12546 Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations

revision to the state implementation

plan shall be considered separately in

light of specific technical, economic,

and environmental factors and in

relation to relevant statutory and

regulatory requirements.

EPA is publishing this action without

prior proposal because the Agency

views this as a noncontroversial

amendment and anticipates no adverse

comments. However, in a separate

document in this Federal Register

publication, the EPA is proposing to

approve the SIP revision should adverse

or critical comments be filed. This

action will be effective May 16, 1997,

unless, by April 16, 1997, adverse or

critical comments are received.

If the EPA receives such comments,

this action will be withdrawn before the

effective date by publishing a

subsequent document that will

withdraw the final action. All public

comments received will then be

addressed in a subsequent final rule

based on this action serving as a

proposed rule. The EPA will not

institute a second comment period on

this action. Any parties interested in

commenting on this action should do so

at this time. If no such comments are

received, the public is advised that this

action will be effective May 16, 1997.

Regulatory Process

Under the Regulatory Flexibility Act,

5 U.S.C. 600 et seq., EPA must prepare

a regulatory flexibility analysis

assessing the impact of any proposed or

final rule on small entities. 5 U.S.C. 603

and 604. Alternatively, EPA may certify

that the rule will not have a significant

impact on a substantial number of small

entities. Small entities include small

businesses, small not-for-profit

enterprises and government entities

with jurisdiction over a population of

less than 50,000.

SIP approvals under sections 110 and

301(a) and subchapter I, Part D of the

CAA do not create any new

requirements, but simply approve

requirements that the State is already

imposing. Therefore, because the

Federal SIP-approval does not impose

any new requirements, I certify that it

does not have a significant impact on

any small entities affected. Moreover,

due to the nature of the Federal-state

relationship under the CAA, preparation

of a regulatory flexibility analysis would

constitute Federal inquiry into the

economic reasonableness of state action.

The CAA forbids EPA to base its

actions concerning SIPs on such

grounds. Union Electric Co. v. U.S.

E.P.A., 427 U.S. 246, 256–66 (S. Ct.

1976); 42 U.S.C. 7410 (a)(2).

Unfunded Mandates

Under Sections 202, 203, and 205 of

the Unfunded Mandates Reform Act of

1995 (‘‘Unfunded Mandates Act’’),

signed into law on March 22, 1995, EPA

must undertake various actions in

association with proposed or final rules

that include a Federal mandate that may

result in estimated costs of $100 million

or more to the private sector or to State,

local, or tribal governments in the

aggregate.

Through submission of this state

implementation plan or plan revision,

the State and any affected local or tribal

governments have elected to adopt the

program provided for under Part D of

the Clean Air Act. These rules may bind

State, local, and tribal governments to

perform certain actions and also require

the private sector to perform certain

duties. The rule being approved by this

action will impose no new requirements

because affected sources are already

subject to these regulations under State

law. Therefore, no additional costs to

State, local, or tribal governments or to

the private sector result from this action.

EPA has also determined that this final

action does not include a mandate that

may result in estimated costs of $100

million or more to State, local, or tribal

governments in the aggregate or to the

private sector.

Under 5 U.S.C. 801(a)(1)(A) as added

by the Small Business Regulatory

Enforcement Fairness Act of 1996, EPA

submitted a report containing this rule

and other required information to the

U.S. Senate, the U.S. House of

Representatives and the Comptroller

General of the General Accounting

Office prior to publication of the rule in

today’s Federal Register. This rule is

not a ‘‘major rule’’ as defined by 5

U.S.C. 804(2).

This action has been classified as a

Table 3 action for signature by the

Regional Administrator under the

procedures published in the Federal

Register on January 19, 1989 (54 FR

2214–2225), as revised by a July 10,

1995 memorandum from Mary Nichols,

Assistant Administrator for Air and

Radiation. The Office of Management

and Budget (OMB) has exempted this

regulatory action from Executive Order

12866 review.

List of Subjects in 40 CFR Part 52

Environmental protection, Air

pollution control, Hydrocarbons,

Incorporation by reference,

Intergovernmental relations, Ozone,

Reporting and recordkeeping

requirements, Volatile organic

compounds.

Note: Incorporation by reference of the

State Implementation Plan for the State of

California was approved by the Director of

the Federal Register on July 1, 1982.

Dated: February 19, 1997.

Nora L. McGee,

Acting Regional Administrator.

Part 52, chapter I, title 40 of the Code

of Federal Regulations is amended as

follows:

PART 52—[AMENDED]

1. The authority citation for Part 52

continues to read as follows:

Authority: 42 U.S.C. 7401–7671q

Subpart D—Arizona

2. Section 52.120 is amended by

adding paragraph (c)(82) to read as

follows:

§ 52.120 Identification of plan.

* * * * *

(c) * * *

(82) New and amended rules and

regulations for the Maricopa County

Environmental Services Department—

Air Pollution Control were submitted on

August 31, 1995, by the Governor’s

designee.

(i) Incorporated by reference.

(A) Rule 343, adopted on February 15,

1995.

* * * * *

[FR Doc. 97–5972 Filed 3–14–97; 8:45 am]

BILLING CODE 6560–50–P

40 CFR Part 63

[FRL–5700–9]

RIN 2060–AE37

Test Methods for the Polymers and

Resins I Rule; Appendix A, Test

Methods 310 A, B, C, 312 A, B, C, 313

A, B

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Final rule.

SUMMARY: This action promulgates test

methods 310 a, b and c, 312 a, b and c,

and 313 a and b for the detection of

residual amounts of hazardous air

pollutants (HAPs) in conjunction with

the recently issued National Emission

Standards for Hazardous Air Pollutants

(NESHAP) for the Manufacture of Major

Elastomers, (commonly referred to as

Polymers and Resins I). The methods

were adapted from industrial methods

submitted by the facilities in the

polymers and resins industry and were

published for public comment as part of

the Polymers and Resins I proposed

rulemaking action. The methods will be
Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations 12547

promulgated, in conjunction with the

Polymers and Resins I rule, as EPA

methods 310 a, b and c, 312 a, b and c,

and 313 a and b, and will be codified

at 40 CFR Part 63, Appendix A.

Methods 310 a, b, and c are applicable

for determining the residual amount of

solvent (hexane being the most

commonly used solvent) and diene

monomer in ethylene-propylene

terpolymer (EPDM) as produced in the

solution polymerization process.

Methods 312 a, b, and c are applicable

for determining the residual amount of

styrene in styrene-butadiene rubber

(SBR) as produced in the emulsion

polymerization process. Methods 313 a

and b are applicable for determining the

residual amount of toluene, dimer, and

styrene in polybutadiene rubber (PBR)

and SBR crumb as produced in the

solution polymerization process. All of

the methods analyses are through the

use of gas chromatography.

EFFECTIVE DATE: These methods are

effective March 17, 1997.

ADDRESS: The background information

for the promulgated test methods may

be obtained from: Air Docket Section

(LE–131), Attention: Docket No. A–92–

44, U.S. Environmental Protection

Agency, 401 M Street SW., Washington,

DC 20460.

The docket is located at the above

address in room M–1500, Waterside

Mall (ground floor), and may be

inspected from 8 a.m. to 4 p.m., Monday

through Friday; telephone number (202)

382–7548. A reasonable fee may be

charged for copying docket materials.

FOR FURTHER INFORMATION CONTACT: For

information concerning the methods,

contact Mr. Solomon Ricks at (919) 541–

5242, Emission Measurement Center,

Emission Monitoring and Analysis

Division (MD–19), U.S. Environmental

Protection Agency, Research Triangle

Park, North Carolina, 27711.

SUPPLEMENTARY INFORMATION: Response

to Comments: Concurrent with the

proposal of subpart U, the EPA

proposed three test residual HAP test

methods—one each for SBRE, PBR/

SBRS, and EPR. In determining the

methods to be included in the proposal,

the industry was given the opportunity

to submit test methods for evaluation

and approval by the EPA. The EPA

selected the test methods submitted by

the Exxon Chemical Company (Method

310), the Goodyear Tire and Rubber

Company (Method 312), and the

American Synthetic Rubber Corporation

(Method 313) as the test methods to be

used to determine residual HAP

concentration.

After proposal of the test methods,

several commenters stated that no single

analytical method would produce

consistent results for all polymers. It

was suggested by the companies that

each company should be allowed to

demonstrate compliance using a

company-specific method that is

comparable to the EPA test method. The

EPA agreed with the commenters and

concluded that it was appropriate to

allow every interested company to

validate their own test method using a

modified version of 40 CFR part 63,

Appendix A, Method 301.

A total of eight test methods were

submitted by seven different companies.

Throughout the process, the affected

industry has been involved with all

activity associated with the EPA’s

promulgation of the residual organic

HAP test methods. The EPA held

meetings with industry representatives

to discuss their comments on the

proposed methods, and to discuss

procedures for validating company test

methods. Representatives of each of

those three companies which did not

submit test methods were in attendance

at one or more of the meetings.

This notice with the promulgated

regulatory language is also available on

the Technology Transfer Network (TTN)

on the EPA’s electronic bulletin boards.

The TTN provides information and

technology exchange in various areas of

air pollution control. The service is free,

except for the cost of a telephone call.

Dial (919) 541–5742 for up to a 14,400

bps modem. If more information on

TTN is needed, call the HELP line at

(919) 541–5384.

Other materials related to this

rulemaking are available for review in

the docket.

Judicial Review: Under section

307(b)(1) of the Act, judicial review of

the final rule is available only by filing

a petition for review in the U. S. Court

of Appeals for the District of Columbia

Circuit within 60 days of today’s

publication of this final rule. Under

section 307(b)(2) of the Act, the

requirements that are the subject of

today’s notice may not be challenged

later in civil or criminal proceedings

brought by the EPA to enforce these

requirements.

I. Introduction

The methods being promulgated are

to be used in testing for residual

amounts of HAPs to determine

compliance with the standards in the

promulgated Polymers and Resins I rule

(September 5, 1996, 61 FR 46906). The

methods were published for comment

along with the Polymers and Resins I

proposal under the authority of section

112(d) of the Clean Air Act as amended

in 1990. Section 112(d) requires the

Administrator to regulate emissions of

HAP listed in section 112(b) of the

Clean Air Act. The Polymers and Resins

I proposal was published for public

comment on June 12, 1995 (60 FR

30801).

The methods being promulgated will

apply to ethylene-propylene elastomers

production, polybutadiene rubber

production, and styrene-butadiene

rubber and latex production, using

stripping technology as the method of

compliance. As stated in the

promulgated Polymers and Resins I rule,

if compliance is to be demonstrated by

sampling, samples of the stripped wet

crumb or stripped latex must be taken

after the stripper and analyzed to

determine the residual HAP content.

II. Summary of Test Methods

A. Methods 310 a, b, and c

The promulgated methods are

adapted from test methods submitted to

the EPA by DSM Copolymer, Uniroyal

Chemical, and Exxon. These companies

are involved in the manufacture of

EPDM rubber. The basic principle of

DSM Copolymer’s methods involve

heating a sample in a sealed bottle with

an internal standard and analyzing the

vapor by gas chromatography. Uniroyal

Chemical extracts residual hexane

contained in wet pieces of EPDM

polymer with methyl isobutyl ketone

(MIBK). The extract is then analyzed by

gas chromatography. Exxon’s principle

involves dissolving an EPDM crumb

rubber sample in toluene to which

heptane has been added as an internal

standard. Acetone is then added to the

solution to precipitate the crumb, and

the supernatant is then analyzed for

hexane and diene by a gas

chromatograph with a flame ionization

detector (FID).

B. Methods 312 a, b, and c

The promulgated methods are

adapted from a test methods submitted

to the EPA by Goodyear Tire and Rubber

Company, Ameripol Synpol

Corporation, and DSM Copolymer. The

basic principle of the Goodyear method

is to coagulate the SBR latex sample

with an an ethyl alcohol solution

containing a specific amount of alphamethyl styrene as the internal standard,

and analyzing the extract to determine

styrene concentration using a gas

chromatograph with a FID. Ameripol

Synpol coagulates the latex sample in

propanol which contains alpha-methyl

styrene as the internal standard. The

extract is then analyzed by a gas

chromatograph to determine the

residual styrene from the latex. DSM

Copolymer utilizes a packed column gas

chromatograph with a FID to determine
12548 Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations

the concentration of residual styrene in

the latex samples.

C. Methods 313 a and b

The promulgated methods are

adapted from test methods submitted to

the EPA by the American Synthetic

Rubber Corporation (ASRC) and the

Goodyear Tire and Rubber Company.

The basic principle of the ASRC method

involves placing the wet crumb sample

in a sealed vial and running on a

headspace sampler which heats the vial

to a specified temperature for a specific

time and then injects a known volume

of vapor into a capillary gas

chromatograph. The method determines

residual toluene and styrene in the

stripper crumb derived from solution

polymerization processes that utilize

toluene as the polymerization solvent.

The Goodyear method uses the

principle of dissolving the polymer

sample in chloroform and coagulating

the cement with an isopropyl alcohol

solution containing a specific amount of

alpha-methyl styrene as the internal

standard. The extract of this coagulation

is then injected into a gas

chromatograph and separated into

individual components.

III. Significant Comments and Changes

to Test Methods

When published with the Polymers

and Resins I proposal, the methods were

proposed as methods 310, 312, and 313.

The industry submitted their test

methods for EPA review, and it was left

to the EPA to decide which method

would be acceptable as the test methods

to be used for compliance purposes.

However, after proposal, the companies

who submitted their methods for

consideration, and whose methods were

not selected, raised the issue that no

single analytical method would produce

consistent results for all polymers. After

review and consideration of this issue,

the EPA concluded that it was

appropriate to allow every interested

company to validate their own test

method using a modified version of 40

CFR part 63, Appendix A, Method 301.

The results of this effort was to have a

total of eight methods submitted as

validated test methods by seven

companies. Only three affected

companies decided not to submit

methods. Therefore, the final methods

rule include methods 310a, b, and c for

EPR, methods 312a, b, and c for SBRE,

and methods 313a and b for PBR/SBRS,

as acceptable residual organic HAP test

methods.

IV. Administrative Requirements

A. Docket

The docket is an organized and

complete file for all information

submitted or otherwise considered by

EPA in the development of this

promulgated rulemaking. The principal

purposes of the docket are: (1) to allow

interested parties to identify and locate

documents so that they can effectively

participate in the rulemaking process,

and (2) to serve as the record in case of

judicial review (except for interagency

review materials) [Clean Air Act Section

307(d)(7)(A)].

B. Office of Management and Budget

Review

Under Executive Order 12866 (58 FR

51735 October 4, 1993), the EPA is

required to judge whether a regulation

is ‘‘significant’’ and therefore subject to

Office of Management and Budget

(OMB) review and the requirements of

this Executive Order to prepare a

regulatory impact analysis (RIA). The

Order defines ‘‘significant regulatory

action’’ as one that is likely to result in

a rule that may: (1) Have an annual

effect on the economy of $100 million

or more or adversely affect in a material

way the economy, a sector of the

economy, productivity, competition,

jobs, the environment, public health or

safety, or State, local, or tribal

governments or communities; (2) create

a serious inconsistency or otherwise

interfere with an action taken or

planned by another agency; (3)

materially alter the budgetary impact of

entitlements, grants, user fees, or loan

programs, or the rights and obligation of

recipients thereof; or (4) raise novel

legal or policy issues arising out of legal

mandates, the President’s priorities, or

the principles set forth in the Executive

Order.

Pursuant to the terms of the Executive

Order, this action has been determined

to be ‘‘not significant.’’

C. Regulatory Flexibility Act

The EPA has determined that it is not

necessary to prepare a regulatory

flexibility analysis in connection with

this final rule. The EPA has also

determined that this rule will not have

a significant adverse impact on a

substantial number of small businesses.

This rulemaking does not impose

emission measurement requirements

beyond those specified in the current

regulations, nor does it change any

emission standard, rather it provides

acceptable test methods that the

businesses regulated by Polymers and

Resins I may use to comply with that

rule. As such, it will not present a

significant economic impact on a

substantial number of small businesses.

D. Small Business Regulatory

Enforcement Fairness Act of 1996

(SBREFA)

Under 5 U.S.C. 801(a)(1)(A) as added

by the Small Business Regulatory

Enforcement Fairness Act of 1996, EPA

submitted a report containing this rule

and other required information to the

U.S. Senate, the U.S. House of

Representatives and the Comptroller

General of the General Accounting

Office prior to publication of the rule in

today’s Federal Register. This rule is

not a ‘‘major rule’’ as defined by 5

U.S.C. 804(2).

E. Paperwork Reduction Act

The rule does not impose or change

any information collection requirements

subject to Office of Management and

Budget review under the Paperwork

Reduction Act of 1980, 44 U.S.C. 3501

et seq.

F. Unfunded Mandates

Under Section 202 of the Unfunded

Mandates Reform Act of 1995

(’’Unfunded Mandates Act’’), signed

into law on March 22, 1995, EPA must

prepare a budgetary impact statement to

accompany any proposed or final rule

that includes a Federal mandate that

may result in estimated costs to State,

local, or tribal governments in the

aggregate; or to the private sector, of

$100 million or more. Under Section

205, EPA must select the most costeffective and least burdensome

alternative that achieves the objectives

of the rule and is consistent with

statutory requirements. Section 203

requires EPA to establish a plan for

significantly or uniquely impacted by

the rule.

EPA has determined that the action

proposed today does not include a

Federal mandate that may result in

estimated costs of $100 million or more

to either State, local, or tribal

governments in the aggregate, or to the

private sector, nor does this action

significantly or uniquely impact small

governments, because this action

contains no requirements that apply to

such govenments or impose obligations

upon them. Therefore, the requirements

of the Unfunded Mandates Act do not

apply to this action.

List of Subjects in 40 CFR Part 63

Environmental protection, Emulsion

polymerization, Gas chromatography,

Residual Hydrocarbon, Styrene,

Solution polymerization.
Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations 12549

Dated: March 4, 1997.

Carol M. Browner,

Administrator.

For the reasons set out in the

preamble, Appendix A of Part 63 of

Title 40 of the CFR is amended as

follows:

PART 63—[AMENDED]

1. The authority citation for Part 63

continues to read as follows:

Authority: 42 U.S.C. 7401, et seq.

2. Appendix A of Part 63 is amended

by adding methods 310, 312, and 313 to

read as follows:

APPENDIX A—TEST METHODS

* * * * *

METHOD 310A—DETERMINATION

OF RESIDUAL HEXANE THROUGH

GAS CHROMATOGRAPHY

1.0 Scope and Application

1.1 This method is used to analyze any

crumb rubber or water samples for

residual hexane content.

1.2 The sample is heated in a sealed

bottle with an internal standard and

the vapor is analyzed by gas

chromatography.

2.0 Summary of Method

2.1 This method, utilizing a capillary

column gas chromatograph with a

flame ionization detector,

determines the concentration of

residual hexane in rubber crumb

samples.

3.0 Definitions

3.1 The definitions are included in the

text as needed.

4.0 Interferences

4.1 There are no known interferences.

5.0 Safety

5.1 It is the responsibility of the user

of this procedure to establish safety

and health practices applicable to

their specific operation.

6.0 Equipment and Supplies

6.1 Gas Chromatograph with a flame

ionization detector and data

handling station equipped with a

capillary column 30 meters long.

6.2 Chromatograph conditions for

Sigma 1:

6.2.1 Helium pressure: 50# inlet A, 14#

aux

6.2.2 Carrier flow: 25 cc/min

6.2.3 Range switch: 100x

6.2.4 DB: 1 capillary column

6.3 Chromatograph conditions for

Hewlett-Packard GC:

6.3.1 Initial temperature: 40 °C

6.3.2 Initial time: 8 min

6.3.3 Rate: 0

6.3.4 Range: 2

6.3.5 DB: 1705 capillary column

6.4 Septum bottles and stoppers

6.5 Gas Syringe—0.5 cc

7.0 Reagents and Standards

7.1 Chloroform, 99.9+%, A.S.C. HPLC

grade

8.0 Sample Collection, Preservation,

and Storage

8.1 A representative sample should be

caught in a clean 8 oz. container

with a secure lid.

8.2 The container should be labeled

with sample identification, date and

time.

9.0 Quality Control

9.1 The instrument is calibrated by

injecting calibration solution

(Section 10.2 of this method) five

times.

9.2 The retention time for components

of interest and relative response of

monomer to the internal standard is

determined.

9.3 Recovery efficiency must be

determined once for each sample

type and whenever modifications

are made to the method.

9.3.1 Determine the percent hexane

in three separate dried rubber

crumb samples.

9.3.2 Weigh a portion of each crumb

sample into separate sample bottles

and add a known amount of hexane

(10 microliters) by microliter

syringe and 20 microliters of

internal standard. Analyze each by

the described procedure and

calculate the percent recovery of the

known added hexane.

9.3.3 Repeat the previous step using

twice the hexane level (20

microliters), analyze and calculate

the percent recovery of the known

added hexane.

9.3.4 Set up two additional sets of

samples using 10 microliters and 20

microliters of hexane as before, but

add an amount of water equal to the

dry crumb used. Analyze and

calculate percent recovery to show

the effect of free water on the

results obtained.

9.3.5 A value of R between 0.70 and

1.30 is acceptable.

9.3.6 R shall be used to correct all

reported results for each compound

by dividing the measured results of

each compound by the R for that

compound for the same sample

type.

10.0 Calibration and Instrument

Settings

10.1 Calibrate the chromatograph

using a standard made by injecting

10 μl of fresh hexane and 20 μl of

chloroform into a sealed septum

bottle. This standard will be 0.6

wt.% total hexane based on 1 gram

of dry rubber.

10.2 Analyze the hexane used and

calculate the percentage of each

hexane isomer (2-methylpentane, 3-

methylpentane, n-hexane, and

methylcyclo-pentane). Enter these

percentages into the method

calibration table.

10.3 Heat the standard bottle for 30

minutes in a 105 °C oven.

10.4 Inject about 0.25 cc of vapor into

the gas chromatograph and after the

analysis is finished, calibrate

according to the procedures

described by the instrument

manufacturer.

11.0 Procedure

11.1 Using a cold mill set at a wide

roller gap (125–150 mm), mill about

250 grams of crumb two times to

homogenize the sample.

11.2 Weigh about 2 grams of wet

crumb into a septum bottle and cap

with a septum ring. Add 20 μl of

chloroform with a syringe and place

in a 105 °C oven for 45 minutes.

11.3 Run the moisture content on a

separate portion of the sample and

calculate the grams of dry rubber

put into the septum bottle.

11.4 Set up the data station on the

required method and enter the dry

rubber weight in the sample weight

field.

11.5 Inject a 0.25 cc vapor sample into

the chromatograph and push the

start button.

11.6 At the end of the analysis, the

data station will print a report

listing the concentration of each

identified component.

11.7 To analyze water samples, pipet 5

ml of sample into the septum bottle,

cap and add 20 μl of chloroform.

Place in a 105 °C oven for 30

minutes.

11.8 Enter 5 grams into the sample

weight field.

11.9 Inject a 0.25 cc vapor sample into

the chromatograph and push the

start button.

11.10 At the end of the analysis, the

data station will print a report

listing the concentration of each

identified component.

12.0 Data Analysis and Calculation

12.1 For samples that are prepared as

in section 11 of this method, ppm
12550 Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations

n-hexane is read directly from the

computer.

12.2 The formulas for calculation of

the results are as follows:

ppmhexane=(Ahexane×Rhexane)/(Ais×Ris)

Where:

Ahexane=area of hexane

Rhexane=response of hexane

Ais=area of the internal standard

Ris=response of the internal standard

% hexane in crumb=(ppmhexane/sample

amount)100

12.3 Correct the results by the value of

R (as determined in sections 9.3.4,

9.3.5, and 9.3.6 of this method).

13.0 Method Performance

13.1 The test has a standard deviation

of 0.14 wt% at 0.66 wt% hexane.

Spike recovery of 12 samples at two

levels of hexane averaged 102.3%.

Note: Recovery must be determined

for each type of sample. The values

given here are meant to be examples

of method performance.

14.0 Pollution Prevention

14.1 Waste generation should be

minimized where possible. Sample

size should be an amount necessary

to adequately run the analysis.

15.0 Waste Management

15.1 All waste shall be handled in

accordance with federal and state

environmental regulations.

16.0 References and Publications

16.1 DSM Copolymer Test Method T–

3380.

METHOD 310B—DETERMINATION OF

RESIDUAL HEXANE THROUGH GAS

CHROMATOGRAPHY

1.0 Scope and Application

Analyte CAS No. Matrix

Method sensitivity (5.5g

sample size)

Hexane ....................................................................................................................... 110–54–3 Rubber crumb ................... .01 wt%.

Ethylidene norbornene (ENB) .................................................................................... 16219–75–3 Rubber crumb ................... .001 wt%.

1.1 Data Quality Objectives:

In the production of ethylenepropylene terpolymer crumb rubber, the

polymer is recovered from solution by

flashing off the solvent with steam and

hot water. The resulting water-crumb

slurry is then pumped to the finishing

units. Certain amounts of solvent

(hexane being the most commonly used

solvent) and diene monomer remain in

the crumb. The analyst uses the

following procedure to determine those

amounts.

2.0 Summary of Method

2.1 The crumb rubber sample is

dissolved in toluene to which

heptane has been added as an

internal standard. Acetone is then

added to this solution to precipitate

the crumb, and the supernatant is

analyzed for hexane and diene by a

gas chromatograph equipped with a

flame ionization detector (FID).

3.0 Definitions

3.1 Included in text as needed.

4.0 Interferences

4.1 None known.

4.2 Benzene, introduced as a

contaminant in the toluene solvent,

elutes between methyl

cyclopentane and cyclohexane.

However, the benzene peak is

completely resolved.

4.3 2,2-dimethyl pentane, a minor

component of the hexane used in

our process, elutes just prior to

methyl cyclopentane. It is included

as ‘‘hexane’’ in the analysis whether

it is integrated separately or

included in the methyl

cyclopentane peak.

5.0 Safety

5.1 This procedure does not purport to

address all of the safety concerns

associated with its use. It is the

responsibility of the user of this

procedure to establish appropriate

safety and health practices and

determine the applicability of

regulatory limitations prior to use.

5.2 Chemicals used in this analysis are

flammable and hazardous (see

specific toxicity information

below). Avoid contact with sources

of ignition during sample prep. All

handling should be done beneath a

hood. Playtex or nitrile gloves

recommended.

5.3 Hexane is toxic by ingestion and

inhalation. Vapor inhalation causes

irritation of nasal and respiratory

passages, headache, dizziness,

nausea, central nervous system

depression. Chronic overexposure

can cause severe nerve damage.

May cause irritation on contact with

skin or eyes. May cause damage to

kidneys.

5.3 ENB may be harmful by inhalation,

ingestion, or skin absorption. Vapor

or mist is irritating to the eyes,

mucous membranes, and upper

respiratory tract. Causes skin

irritation.

5.4 Toluene is harmful or fatal if

swallowed. Vapor harmful if

inhaled. Symptoms: headache,

dizziness, hallucinations, distorted

perceptions, changes in motor

activity, nausea, diarrhea,

respiratory irritation, central

nervous system depression,

unconsciousness, liver, kidney and

lung damage. Contact can cause

severe eye irritation. May cause

skin irritation. Causes irritation of

eyes, nose, and throat.

5.5 Acetone, at high concentrations or

prolonged overexposure, may cause

headache, dizziness, irritation of

eyes and respiratory tract, loss of

strength, and narcosis. Eye contact

causes severe irritation; skin contact

may cause mild irritation.

Concentrations of 20,000 ppm are

immediately dangerous to life and

health.

5.6 Heptane is harmful if inhaled or

swallowed. May be harmful if

absorbed through the skin. Vapor or

mist is irritating to the eyes,

mucous membranes, and upper

respiratory tract. Prolonged or

repeated exposure to skin causes

defatting and dermatitis.

5.7 The steam oven used to dry the

polymer in this procedure is set at

110° C. Wear leather gloves when

removing bottles from the oven.

6.0 Equipment and Supplies

6.1 4000-ml volumetric flask

6.2 100-ml volumetric pipette

6.3 1000-ml volumetric flask

6.4 8-oz. French Square sample bottles

with plastic-lined caps

6.5 Top-loading balance

6.6 Laboratory shaker

6.7 Laboratory oven set at 110° C

(steam oven)

6.8 Gas chromatograph, HewlettPackard 5890A, or equivalent,

interfaced with HP 7673A (or

equivalent) autosampler (equipped

with nanoliter adapter and robotic

arm), and HP 3396 series II or

3392A (or equivalent) integrator/

controller.

6.9 GC column, capillary type, 50m ×

0.53mm, methyl silicone, 5 micron
Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations 12551

film thickness, Quadrex, or

equivalent.

6.10 Computerized data acquisition

system, such as CIS/CALS

6.11 Crimp-top sample vials and HP p/

n 5181–1211 crimp caps.

6.12 Glass syringes, 5-ml, with ‘‘Luerlock’’ fitting

6.13 Filters, PTFE, .45μm pore size,

Gelman Acrodisc or equivalent, to

fit on Luer-lock syringes (in 6.12,

above).

7.0 Reagents and Standards

7.1 Reagent toluene, EM Science

Omnisolv

Purity Check: Prior to using any bottle

of reagent toluene, analyze it

according to section 11.2 of this

method. Use the bottle only if

hexane, heptane, and ENB peak

areas are less than 15 each (note

that an area of 15 is equivalent to

less than 0.01 wt% in a 10g

sample).

7.2 Reagent acetone, EM Science

Omnisolv HR–GC

Purity Check: Prior to using any bottle

of reagent acetone, analyze it

according to section 11.2 of this

method. Use the bottle only if

hexane, heptane, and ENB peak

areas are less than 15 each.

7.3 Reagent heptane, Aldrich Chemical

Gold Label, Cat #15,487–3

Purity Check: Prior to using any bottle

of reagent heptane, analyze it

according to section 11.2 of this

method. Use the bottle only if

hexane and ENB peak areas are less

than 5 each.

7.4 Internal standard solution—used

as a concentrate for preparation of

the more dilute Polymer Dissolving

Solution. It contains 12.00g

heptane/100ml of solution which is

120.0g per liter.

Preparation of internal standard

solution (polymer dissolving stock

solution):

Action Notes

7.4.1 Tare a clean, dry 1-liter volumetric flask on the balance. Record

the weight to three places.

If the 1-liter volumetric flask is too tall to fit in the balance case, you

can shield the flask from drafts by inverting a paint bucket with a

hole cut in the bottom over the balance cover. Allow the neck of the

flask to project through the hole in the bucket.

7.4.2 Weigh 120.00 g of n-heptane into the flask. Record the total

weight of the flask and heptane as well as the weight of heptane

added.

Use 99+% n-heptane from Aldrich or Janssen Chimica.

7.4.3 Fill the flask close to the mark with toluene, about 1 to 2′′ below

the mark.

Use EM Science Omnisolve toluene, Grade TX0737–1, or equivalent.

7.4.4 Shake the flask vigorously to mix the contents ............................ Allow any bubbles to clear before proceeding to the next step.

7.4.5 Top off the flask to the mark with toluene. Shake vigorously, as

in section 5.4.4 of this method, to mix well.

7.4.6 Weigh the flask containing the solution on the three place balance record the weight

7.4.7 Transfer the contents of the flask to a 1 qt Boston round bottle .... Discard any excess solution

7.4.8 Label the bottle with the identity of the contents, the weights of

heptane and toluene used, the date of preparation and the preparer’s

name.

Be sure to include the words ‘‘Hexane in Crumb Polymer Dissolving

Stock Solution’’ on the label.

7.4.9 Refrigerate the completed blend for the use of the routine Technicians.

7.5 Polymer Dissolving Solution

(‘‘PDS’’)—Heptane (as internal

standard) in toluene. This solution

contains 0.3g of heptane internal

standard per 100 ml of solution.

7.5.1 Fill a 4000ml volumetric flask

about 3⁄4 full with toluene.

7.5.2 Add 100 ml of the internal

standard solution (section 7.4 of

this method) to the flask using the

100ml pipette.

7.5.3 Fill the flask to the mark with

toluene. Discard any excess.

7.5.4 Add a large magnetic stirring

bar to the flask and mix by stirring.

7.5.5 Transfer the polymer solvent

solution to the one-gallon labeled

container with 50ml volumetric

dispenser attached.

7.5.6 Purity Check: Analyze

according to section 11.2. NOTE:

You must ‘‘precipitate’’ the sample

with an equal part of acetone (thus

duplicating actual test conditions—

see section 11.1 of this method,

sample prep) before analyzing.

Analyze the reagent 3 times to

quantify the C6 and ENB

interferences. Inspect the results to

ensure good agreement among the

three runs (within 10%).

7.5.7 Tag the bottle with the

following information:

POLYMER DISSOLVING

SOLUTION FOR C6 IN CRUMB

ANALYSIS

PREPARER’S NAME

DATE

CALS FILE ID’S OF THE THREE

ANALYSES FOR PURITY (from

section 7.5.6 of this method)

7.6 Quality Control Solution: the

quality control solution is prepared

by adding specific amounts of

mixed hexanes (barge hexane), nnonane and ENB to some polymer

dissolving solution. Nonane elutes

in the same approximate time

region as ENB and is used to

quantify in that region because it

has a longer shelf life. ENB, having

a high tendency to polymerize, is

used in the QC solution only to

ensure that both ENB isomers elute

at the proper time.

First, a concentrated stock solution is

prepared; the final QC solution can

then be prepared by diluting the

stock solution.

7.6.1 In preparation of stock

solution, fill a 1-liter volumetric

flask partially with polymer

dissolving solution (PDS)—see

section 7.5 of this method. Add 20.0

ml barge hexane, 5.0 ml n-nonane,

and 3 ml ENB. Finish filling the

volumetric to the mark with PDS.

7.6.2 In preparation of quality

control solution, dilute the quality

control stock solution (above)

precisely 1:10 with PDS, i.e. 10 ml

of stock solution made up to 100 ml

(volumetric flask) with PDS. Pour

the solution into a 4 oz. Boston

round bottle and store in the

refrigerator.

8.0 Sample Collection, Preservation

and Storage

8.1 Line up facility to catch crumb

samples. The facility is a special

facility where the sample is drawn.

8.1.1 Ensure that the cock valve

beneath facility is closed.
12552 Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations

8.1.2 Line up the system from the

slurry line cock valve to the cock

valve at the nozzle on the stripper.

8.1.3 Allow the system to flush

through facility for a period of 30

seconds.

8.2 Catch a slurry crumb sample.

8.2.1 Simultaneously close the cock

valves upstream and downstream of

facility.

8.2.2 Close the cock valve beneath

the slurry line in service.

8.2.3 Line up the cooling tower

water through the sample bomb

water jacket to the sewer for a

minimum of 30 minutes.

8.2.4 Place the sample catching

basket beneath facility and open the

cock valve underneath the bomb to

retrieve the rubber crumb.

8.2.5 If no rubber falls by gravity

into the basket, line up nitrogen to

the bleeder upstream of the sample

bomb and force the rubber into the

basket.

8.2.6 Close the cock valve

underneath the sample bomb.

8.3 Fill a plastic ‘‘Whirl-pak’’ sample

bag with slurry crumb and send it

to the lab immediately.

8.4 Once the sample reaches the lab, it

should be prepped as soon as

possible to avoid hexane loss

through evaporation. Samples

which have lain untouched for

more than 30 minutes should be

discarded.

9.0 Quality Control

Quality control is monitored via a

computer program that tracks analyses

of a prepared QC sample (from section

7.6.2 of this method). The QC sample

result is entered daily into the program,

which plots the result as a data point on

a statistical chart. If the data point does

not satisfy the ‘‘in-control’’ criteria (as

defined by the lab quality facilitator), an

‘‘out-of-control’’ flag appears, mandating

corrective action.

In addition, the area of the n-heptane

peak is monitored so that any errors in

making up the polymer dissolving

solution will be caught and corrected.

Refer to section 12.4 of this method.

9.1 Fill an autosampler vial with the

quality control solution (from

section 7.6.2 of this method) and

analyze on the GC as normal (per

section 11 of this method).

9.2 Add the concentrations of the 5

hexane isomers as they appear on

the CALS printout. Also include the

2,2-dimethyl-pentane peak just

ahead of the methyl cyclopentane

(the fourth major isomer) peak in

the event that the peak integration

split this peak out. Do not include

the benzene peak in the sum. Note

the nonane concentration. Record

both results (total hexane and

nonane) in the QC computer

program. If out of control, and GC

appears to be functioning within

normal parameters, reanalyze a

fresh control sample. If the fresh QC

is not in control, check stock

solution for contaminants or make

up a new QC sample with the

toluene currently in use. If

instrument remains out-of-control,

more thorough GC troubleshooting

may be needed.

Also, verify that the instrument has

detected both isomers of ENB

(quantification not necessary—see

section 7.0 of this method).

9.3 Recovery efficiency must be

determined for each sample type

and whenever modifications are

made to the method. Recovery shall

be between 70 and 130 percent. All

test results must be corrected by the

recovery efficiency value (R).

9.3.1 Approximately 10 grams of wet

EPDM crumb (equivalent to about 5

grams of dry rubber) shall be added

to six sample bottles containing 100

ml of hexane in crumb polymer

dissolving solution (toluene

containing 0.3 gram n-heptane/100

ml solution). The polymer shall be

dissolved by agitating the bottles on

a shaker for 4 hours. The polymer

shall be precipitated using 100 ml

acetone.

9.3.2 The supernatant liquid shall be

decanted from the polymer. Care

shall be taken to remove as much of

the liquid phase from the sample as

possible to minimize the effect of

retained liquid phase upon the next

cycle of the analysis. The

supernatant liquid shall be

analyzed by gas chromatography

using an internal standard

quantitation method with heptane

as the internal standard.

9.3.3 The precipitated polymer from

the steps described above shall be

re-dissolved using toluene as the

solvent. The toluene solvent and

acetone precipitant shall be

determined to be free of interfering

compounds.

9.3.4 The rubber which was

dissolved in the toluene shall be

precipitated with acetone as before,

and the supernatant liquid decanted

from the precipitated polymer. The

liquid shall be analyzed by gas

chromatography and the rubber

phase dried in a steam-oven to

determine the final polymer weight.

9.3.5 The ratios of the areas of the

hexane peaks and of the heptane

internal standard peak shall be

calculated for each of the six

samples in the two analysis cycles

outlined above. The area ratios of

the total hexane to heptane (R1)

shall be determined for the two

analysis cycles of the sample set.

The ratio of the values of R1 from

the second analysis cycle to the first

cycle shall be determined to give a

second ratio (R2).

10.0 Calibration and Standardization

The procedure for preparing a Quality

Control sample with the internal

standard in it is outlined in section 7.6

of this method.

10.1 The relative FID response factors

for n-heptane, the internal standard,

versus the various hexane isomers

and ENB are relatively constant and

should seldom need to be altered.

However Baseline construction is a

most critical factor in the

production of good data. For this

reason, close attention should be

paid to peak integration. Procedures

for handling peak integration will

depend upon the data system used.

10.2 If recalibration of the analysis is

needed, make up a calibration

blend of the internal standard and

the analytes as detailed below and

analyze it using the analytical

method used for the samples.

10.2.1 Weigh 5 g heptane into a

tared scintillation vial to five

places.

10.2.2 Add 0.2 ml ENB to the vial

and reweigh.

10.2.3 Add 0.5 ml hexane to the vial

and reweigh.

10.2.4 Cap, and shake vigorously to

mix.

10.2.5 Calculate the weights of ENB

and of hexane added and divide

their weights by the weight of the

n-heptane added. The result is the

known of given value for the

calibration.

10.2.6 Add 0.4 ml of this mixture to

a mixture of 100 ml toluene and 100

ml of acetone. Cap and shake

vigorously to mix.

10.2.7 Analyze the sample.

10.2.8 Divide the ENB area and the

total areas of the hexane peaks by

the n-heptane area. This result is

the ‘‘found’’ value for the

calibration.

10.2.9 Divide the appropriate

‘‘known’’ value from 10.2.5 by the

found value from 10.2.8. The result

is the response factor for the analyte

in question. Previous work has

shown that the standard deviation

of the calibration method is about

1% relative.

11.0 Procedure

11.1 SAMPLE PREPARATION
Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations 12553

11.1.1 Tare an 8oz sample bottle—

Tag attached, cap off; record weight

and sample ID on tag in pencil.

11.1.2 Place crumb sample in bottle:

RLA–1: 20g; RLA–3: 10g—(gives a

dry wt of ∼10g); (gives a dry wt of

∼5.5g).

11.1.3 Dispense 100ml of PDS into

each bottle. SAMPLE SHOULD BE

PLACED INTO SOLUTION ASAP

TO AVOID HEXANE LOSS—Using

‘‘Dispensette’’ pipettor. Before

dispensing, ‘‘purge’’ the dispensette

(25% of its volume) into a waste

bottle to eliminate any voids.

11.1.4 Tightly cap bottles and load

samples into shaker.

11.1.5 Insure that ‘‘ON–OFF’’ switch

on the shaker itself is ‘‘ON.’’

11.1.6 Locate shaker timer. Insure

that toggle switch atop timer control

box is in the middle (‘‘off’’)

position. If display reads ‘‘04:00’’ (4

hours), move toggle switch to the

left position. Shaker should begin

operating.

11.1.7 After shaker stops, add 100

ml acetone to each sample to

precipitate polymer. Shake

minimum of 5 minutes on shaker—

Vistalon sample may not have fully

dissolved; nevertheless, for

purposes of consistency, 4 hours is

the agreed-upon dissolving time.

11.1.8 Using a 5-ml glass Luer-lock

syringe and Acrodisc filter, filter

some of the supernatant liquid into

an autosampler vial; crimp the vial

and load it into the GC autosampler

for analysis (section 11.2 of this

method)—The samples are filtered

to prevent polymer buildup in the

GC. Clean the syringes in toluene.

11.1.9 Decant remaining supernatant

into a hydrocarbon waste sink,

being careful not to discard any of

the polymer. Place bottle of

precipitate into the steam oven and

dry for six hours—Some grades of

Vistalon produce very small

particles in the precipitate, thus

making complete decanting

impossible without discarding some

polymer. In this case, decant as

much as possible and put into the

oven as is, allowing the oven to

drive off remaining supernatant

(this practice is avoided for

environmental reasons). WARNING:

OVEN IS HOT—110 °C (230° F).

11.1.10 Cool, weigh and record final

weight of bottle.

11.2 GC ANALYSIS

11.2.1 Initiate the CALS computer

channel.

11.2.2 Enter the correct instrument

method into the GC’s integrator.

11.2.3 Load sample vial(s) into

autosampler.

11.2.4 Start the integrator.

11.2.5 When analysis is complete,

plot CALS run to check baseline

skim.

12.0 Data Analysis and Calculations

12.1 Add the concentrations of the

hexane peaks as they appear on the

CALS printout. Do not include the

benzene peak in the sum.

12.2 Subtract any hexane interferences

found in the PDS (see section 7.5.6

of this method); record the result.

12.3 Note the ENB concentration on

the CALS printout. Subtract any

ENB interference found in the PDS

and record this result in a ‘‘% ENB

by GC’’ column in a logbook.

12.4 Record the area (from CALS

printout) of the heptane internal

standard peak in a ‘‘C7 area’’

column in the logbook. This helps

track instrument performance over

the long term.

12.5 After obtaining the final dry

weight of polymer used (section

11.1.10 of this method), record that

result in a ‘‘dry wt.’’ column of the

logbook.

12.6 Divide the %C6 by the dry weight

to obtain the total PHR hexane in

crumb. Similarly, divide the %ENB

by the dry weight to obtain the total

PHR ENB in crumb. Note that PHR

is an abbreviation for ‘‘parts per

hundred’’. Record both the hexane

and ENB results in the logbook.

12.7 Correct all results by the recovery

efficiency value (R).

13.0 Method Performance

13.1 The method has been shown to

provide 100% recovery of the

hexane analyte. The method was

found to give a 6% relative standard

deviation when the same six

portions of the same sample were

carried through the procedure.

Note: These values are examples;

each sample type must be tested for

sample recovery.

14.0 Pollution Prevention

14.1 Dispose of all hydrocarbon

liquids in the appropriate disposal

sink system; never pour

hydrocarbons down a water sink.

14.2 As discussed in section 11.1.9 of

this method, the analyst can

minimize venting hydrocarbon

vapor to the atmosphere by

decanting as much hydrocarbon

liquid as possible before oven

drying.

15.0 Waste Mamagement

15.1 The Technician conducting the

analysis should follow the proper

waste management practices for

their laboratory location.

16.0 References

16.1 Baton Rouge Chemical Plant

Analytical Procedure no. BRCP

1302

16.2 Material Safety Data Sheets (from

chemical vendors) for hexane, ENB,

toluene, acetone, and heptane

METHOD 310C—DETERMINATION OF

RESIDUAL N-HEXANE IN EPDM

RUBBER THROUGH GAS

CHROMATOGRAPHY

1.0 Scope and Application

1.1 This method describes a procedure

for the determination of residual

hexane in EPDM wet crumb rubber

in the 0.01—2% range by solvent

extraction of the hexane followed

by gas chromatographic analysis

where the hexane is detected by

flame ionization and quantified via

an internal standard.

1.2 This method may involve

hazardous materials operations and

equipment. This method does not

purport to address all the safety

problems associated with it use, if

any. It is the responsibility of the

user to consult and establish

appropriate safety and health

practices and determine the

applicability of regulatory

limitations prior to use.

2.0 Summary

2.1 Residual hexane contained in wet

pieces of EPDM polymer is

extracted with MIBK. A known

amount of an internal standard (IS)

is added to the extract which is

subsequently analyzed via gas

chromatography where the hexane

and IS are separated and detected

utilizing a megabore column and

flame ionization detection (FID).

From the response to the hexane

and the IS, the amount of hexane in

the EPDM polymer is calculated.

3.0 Definitions

3.1 Hexane—refers to n-hexane

3.2 Heptane—refers to n-heptane

3.3 MIBK—methyl isobutyl ketone (4

methyl 2—Pentanone)

4.0 Interferences

4.1 Material eluting at or near the

hexane and/or the IS will cause

erroneous results. Prior to

extraction, solvent blanks must be

analyzed to confirm the absence of

interfering peaks.

5.0 Safety

5.1 Review Material Safety Data Sheets

of the chemicals used in this

method.
12554 Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations

6.0 Equipment and Supplies

6.1 4 oz round glass jar with a wide

mouth screw cap lid.

6.2 Vacuum oven.

6.3 50 ml pipettes.

6.4 A gas chromatograph with an auto

sampler and a 50 meter, 0.53 ID,

methyl silicone column with 5

micron phase thickness.

6.5 Shaker, large enough to hold 10, 4

oz. jars.

6.6 1000 and 4000 ml volumetric

flasks.

6.7 Electronic integrator or equivalent

data system.

6.8 GC autosampler vials.

6.9 50 uL syringe.

7.0 Reagents and Standards

7.1 Reagent grade Methyl-Iso-ButylKetone (MIBK)

7.2 n-heptane, 99% + purity

7.3 n-hexane, 99% + purity

8.0 Sample Collection

8.1 Trap a sample of the EPDM crumb

slurry in the sampling apparatus.

Allow the crumb slurry to circulate

through the sampling apparatus for

5 minutes; then close off the values

at the bottom and top of the

sampling apparatus, trapping the

crumb slurry. Run cooling water

through the water jacket for a

minimum of 30 minutes. Expel the

cooled crumb slurry into a sample

catching basket. If the crumb does

not fall by gravity, force it out with

demineralized water or nitrogen.

Send the crumb slurry to the lab for

analysis.

9.0 Quality Control

9.1 The Royalene crumb sample is

extracted three times with MIBK

containing an internal standard.

The hexane from each extraction is

added together to obtain a total

hexane content. The percent hexane

in the first extraction is then

calculated and used as the recovery

factor for the analysis.

9.2 Follow this test method through

section 11.4 of the method. After

removing the sample of the first

extraction to be run on the gas

chromatograph, drain off the

remainder of the extraction solvent,

retaining the crumb sample in the

sample jar. Rinse the crumb with

demineralized water to remove any

MIBK left on the surface of the

crumb. Repeat the extraction

procedure with fresh MIBK with

internal standard two more times.

9.3 After the third extraction, proceed

to section 11.5 of this method and

obtain the percent hexane in each

extraction. Use the sample weight

obtained in section 12.1 of this

method to calculate the percent

hexane in each of the extracts.

9.4 Add the percent hexane obtained

from the three extractions for a total

percent hexane in the sample.

9.5 Use the following equations to

determine the recovery factor (R):

% Recovery of the first extraction=(%

hexane in the first extract/total %

hexane)×100

Recovery Factor (R)=(% Hexane

Recovered in the first extract)/100

10.0 Calibration

10.1 Preparation of Internal Standard

(IS) solution:

Accuracy weigh 30 grams of nheptane into a 1000 ml volumetric

flask. Dilute to the mark with

reagent grade MIBK. Label this

Solution ‘‘A’’. Pipette 100 mls. of

Solution A into a 4 liter volumetric

flask. Fill the flask to the mark with

reagent MIBK. Label this Solution

‘‘B’’. Solution ‘‘B’’ will have a

concentration of 0.75 mg/ml of

heptane.

10.2 Preparation of Hexane Standard

Solution (HS):

Using a 50 uL syringe, weigh by difference,

20 mg of n-hexane into a 50 ml volumetric

flask containing approximately 40 ml of

Solution B. Fill the flask to the mark with

Solution B and mix well.

10.3 Conditions for GC analysis of

standards and samples:

Temperature:

Initial=40 °C

Final=150 °C

Injector=160 °C

Detector=280 °C

Program Rate=5.0 °C/min

Initial Time=5 minutes Final Time=6

minutes

Flow Rate=5.0 ml/min

Sensitivity=detector response must be

adjusted to keep the hexane and IS

on scale.

10.4 Fill an autosampler vial with the

HS, analyze it three times and

calculate a Hexane Relative

Response Factor (RF) as follows:

RF=(AIS × CHS × PHS)/(AHS × CIS × PIS) (1)

Where:

A IS=Area of IS peak (Heptane)

AHS=Area of peak (Hexane Standard)

CHS=Mg of Hexane/50 ml HS

CIS=Mg of Heptane/50 ml IS Solution B

PIS=Purity of the IS n-heptane

PHS=Purity of the HS n-hexane

11.0 Procedure

11.1 Weight 10 grams of wet crumb

into a tared (W1), wide mouth 4 oz.

jar.

11.2 Pipette 50 ml of Solution B into

the jar with the wet crumb rubber.

11.3 Screw the cap on tightly and

place it on a shaker for 4 hours.

11.4 Remove the sample from the

shaker and fill an autosampler vial

with the MIBK extract.

11.5 Analyze the sample two times.

11.6 Analyze the HS twice, followed

by the samples. Inject the HS twice

at the end of each 10 samples or at

the end of the run.

12.0 Calculations

12.1 Drain off the remainder of the

MIBK extract from the polymer in

the 4 oz. jar. Retain all the polymer

in the jar. Place the uncovered jar

and polymer in a heated vacuum

oven until the polymer is dry.

Reweigh the jar and polymer (W2)

and calculate the dried sample

weight of the polymer as follows:

Dried SW=W2—W1 (2)

12.2 Should the polymer be oil

extended, pipette 10 ml of the

MIBK extract into a tared

evaporating dish (W1) and

evaporate to dryness on a steam

plate.

Reweigh the evaporating dish

containing the extracted oil (W2).

Calculate the oil content of the polymer

as follows:

Gram of oil extracted =5 (W2—W1) (3)

% Hexane in polymer=(As X RF X CIS

X PIS)/(AIS X SW) (4)

Where:

As=Area of sample hexane sample peak.

AIS=Area of IS peak in sample.

CIS=Concentration of IS in 50 ml.

PIS=Purity of IS.

SW=Weight of dried rubber after

extraction. (For oil extended

polymer, the amount of oil

extracted is added to the dry rubber

weight).

% Corrected Hexane=(% Hexane in

Polymer)/R (5)

R=Recovery factor determined in

section 9 of this method.

13.0 Method Performance

13.1 Performance must be determined

for each sample type by following

the procedures in section 9 of this

method.

14.0 Waste Generation

14.1 Waste generation should be

minimized where possible.

15.0 Waste Management

15.1 All waste shall be handled in

accordance with Federal and State

environmental regulations.

16.0 References

(Reserved)
Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations 12555

METHOD 312A—DETERMINATION

OF STYRENE IN LATEX STYRENEBUTADIENE RUBBER, THROUGH

GAS CHROMATOGRAPHY

1. Scope and Application

1.1 This method describes a procedure

for determining parts per million

(ppm) styrene monomer (CAS No.

100–42–5) in aqueous samples,

including latex samples and styrene

stripper water.

1.2 The sample is separated in a gas

chromatograph equipped with a

packed column and a flame

ionization detector.

2.0 Summary of Method

2.1 This method utilizes a packed

column gas chromatograph with a

flame ionization detector to

determine the concentration of

residual styrene in styrene

butadiene rubber (SBR) latex

samples.

3.0 Definitions

3.1 The definitions are included in the

text as needed.

4.0 Interferences

4.1 In order to reduce matrix effects

and emulsify the styrene, similar

styrene free latex is added to the

internal standard. There are no

known interferences.

4.2 The operating parameters are

selected to obtain resolution

necessary to determine styrene

monomer concentrations in latex.

5.0 Safety

5.1 It is the responsibility of the user

of this procedure to establish

appropriate safety and health

practices.

6.0 Equipment and Supplies

6.1 Adjustable bottle-top dispenser, set

to deliver 3 ml. (for internal

standard), Brinkmann Dispensette,

or equivalent.

6.2 Pipettor, set to 10 ml., Oxford

Macro-set, or equivalent.

6.3 Volumetric flask, 100-ml, with

stopper.

6.4 Hewlett Packard Model 5710A

dual channel gas chromatograph

equipped with flame ionization

detector.

6.4.1 11 ft. × 1⁄8 in. stainless steel

column packed with 10% TCEP on

100/120 mesh Chromosorb P, or

equivalent.

6.4.2 Perkin Elmer Model 023 strip

chart recorder, or equivalent.

6.5 Helium carrier gas, zero grade.

6.6 Liquid syringe, 25-μl.

6.7 Digital MicroVAX 3100 computer

with VG Multichrom software, or

equivalent data handling system.

6.6 Wire Screens, circular, 70-mm, 80-

mesh diamond weave.

6.7 DEHA—(N,N-Diethyl

hydroxylamine), 97+% purity, CAS

No. 3710–84–7

6.8 p-Dioxane, CAS No. 123–91–1

7.0 Reagents and Standards

7.1 Internal standard preparation.

7.1.1 Pipette 5 ml p-dioxane into a

1000-ml volumetric flask and fill to

the mark with distilled water and

mix thoroughly.

7.2 Calibration solution preparation.

7.2.1 Pipette 10 ml styrene-free latex

(eg: NBR latex) into a 100-ml

volumetric flask.

7.2.2 Add 3 ml internal standard

(section 7.1.1 of this method).

7.2.3 Weigh exactly 10μl fresh styrene

and record the weight.

7.2.4 Inject the styrene into the flask

and mix well.

7.2.5 Add 2 drops of DEHA, fill to the

mark with water and mix well

again.

7.2.6 Calculate concentration of the

calibration solution as follows:

mg/l styrene=(mg styrene added)/0.1 L

8.0 Sample Collection, Preservation,

and Storage

8.1 A representative SBR emulsion

sample should be caught in a clean,

dry 6-oz. teflon lined glass

container. Close it properly to

assure no sample leakage.

8.2 The container should be labeled

with sample identification, date and

time.

9.0 Quality Control

9.1 The instrument is calibrated by

injecting calibration solution

(Section 7.2 of this method) five

times.

9.2 The retention time for components

of interest and relative response of

monomer to the internal standard is

determined.

9.3 Recovery efficiency must be

determined once for each sample

type and whenever modifications

are made to the method.

9.3.1 A set of six latex samples shall be

collected. Two samples shall be

prepared for analysis from each

sample. Each sample shall be

analyzed in duplicate.

9.3.2 The second set of six latex

samples shall be analyzed in

duplicate before spiking each

sample with approximately 1000

ppm styrene. The spiked samples

shall be analyzed in duplicate.

9.3.3 For each hydrocarbon, calculate

the average recovery efficiency (R)

using the following equations:

where:

R=Σ(Rn)/6

where:

Rn=(cns¥cv)/Sn

n=sample number

cns=concentration of compound

measured in spiked sample number

n.

cnu= concentration of compound

measured in unspiked sample

number n.

Sn=theoretical concentration of

compound spiked into sample n.

9.3.4 A value of R between 0.70 and

1.30 is acceptable.

9.3.5 R is used to correct all reported

results for each compound by

dividing the measured results of

each compound by the R for that

compound for the same sample

type.

10.0 Calibration and Instrument

Settings

10.1 Injection port temperature, 250°C.

10.2 Oven temperature, 110°C,

isothermal.

10.3 Carrier gas flow, 25 cc/min.

10.4 Detector temperature, 250°C.

10.5 Range, 1X.

11.0 Procedure

11.1 Turn on recorder and adjust

baseline to zero.

11.2 Prepare sample.

11.2.1 For latex samples, add 3 ml

Internal Standard (section 7.1 of

this method) to a 100-ml volumetric

flask. Pipet 10 ml sample into the

flask using the Oxford pipettor,

dilute to the 100-ml mark with

water, and shake well.

11.2.2 For water samples, add 3 ml

Internal Standard (section 7.1 of

this method) to a 100-ml volumetric

flask and fill to the mark with

sample. Shake well.

11.3 Flush syringe with sample.

11.4 Carefully inject 2 μl of sample

into the gas chromatograph column

injection port and press the start

button.

11.5 When the run is complete the

computer will print a report of the

analysis.

12.0 Data Analysis and Calculation

12.1 For samples that are prepared as

in section 11.2.1 of this method:

ppm styrene = A x D

Where:

A = ‘‘ppm’’ readout from computer

D = dilution factor (10 for latex samples)

12.2 For samples that are prepared as

in section 11.2.2 of this method,
12556 Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations

ppm styrene is read directly from

the computer.

13.0 Method Performance

13.1 This test has a standard deviation

(1) of 3.3 ppm at 100 ppm styrene.

The average Spike Recovery from

six samples at 1000 ppm Styrene

was 96.7 percent. The test method

was validated using 926 ppm

styrene standard. Six analysis of the

same standard provided average

97.7 percent recovery. Note: These

are example recoveries and do not

replace quality assurance

procedures in this method.

14.0 Pollution Prevention

14.1 Waste generation should be

minimized where possible. Sample

size should be an amount necessary

to adequately run the analysis.

15.0 Waste Management

15.1 All waste shall be handled in

accordance with Federal and State

environmental regulations.

16.0 References and Publications

16.1 40 CFR 63 Appendix A—Method

301 Test Methods Field Validation

of Pollutant Measurement

16.2 DSM Copolymer Test Method T–

3060, dated October 19, 1995,

entitled: Determination of Residual

Styrene in Latex, Leonard, C.D.,

Vora, N.M.et al

METHOD 312B—DETERMINATION OF

RESIDUAL STYRENE IN STYRENEBUTADIENE (SBR) RUBBER LATEX

BY CAPILLARY GAS

CHROMATOGRAPHY

1.0 Scope

1.1 This method is applicable to SBR

latex solutions.

1.2 This method quantitatively

determines residual styrene

concentrations in SBR latex

solutions at levels from 80 to 1200

ppm.

2.0 Principle of Method

2.1 A weighed sample of a latex

solution is coagulated with an ethyl

alcohol (EtOH) solution containing

a specific amount of alpha-methyl

styrene (AMS) as the internal

standard. The extract of this

coagulation is then injected into a

gas chromatograph and separated

into individual components.

Quantification is achieved by the

method of internal standardization.

3.0 Definitions

3.1 The definitions are included in the

text as needed.

4.0 Interferences

(Reserved)

5.0 Safety

5.1 This method may involve

hazardous materials, operations,

and equipment. This method does

not purport to address all of the

safety problems associated with its

use. It is the responsibility of the

user of this method to establish

appropriate safety and health

practices and determine the

applicability of regulatory

limitations prior to use.

6.0 Equipment and Supplies

6.1 Analytical balance, 160 g capacity,

and 0.1 mg resolution

6.2 Bottles, 2-oz capacity, with polycap screw lids

6.3 Mechanical shaker

6.4 Syringe, 10-ul capacity

6.5 Gas chromatograph, Hewlett

Packard model 5890A, or

equivalent, configured with FID

with a megabore jet, splitless

injector packed with silanized glass

wool.

6.5.1 Establish the following gas

chromatographic conditions, and

allow the system to thoroughly

equilibrate before use.

Injection technique = Splitless

Injector temperature = 225 deg C

Oven temperature = 70 deg C

(isothermal)

Detector: temperature = 300 deg C

range = 5

attenuation = 0

Carrier gas: helium = 47 ml/min

Detector gases: hydrogen = 30 ml/min

air = 270 ml/min

make-up = 0 ml/min

Analysis time: = 3.2 min at the specified

carrier gas flow rate and column

temperature.

6.6 Gas chromatographic column, DB–

1, 30 M X 0.53 ID, or equivalent,

with a 1.5 micron film thickness.

6.7 Data collection system, PerkinElmer/Nelson Series Turbochrom 4

Series 900 Interface, or equivalent.

6.8 Pipet, automatic dispensing, 50-ml

capacity, and 2-liter reservoir.

6.9 Flasks, volumetric, class A, 100-ml

and 1000-ml capacity.

6.10 Pipet, volumetric delivery, 10-ml

capacity, class A.

7.0 Chemicals and Reagents

CHEMICALS:

7.1 Styrene, C8H8, 99+%, CAS 100–

42–5

7.2 Alpha methyl styrene, C9H10,

99%, CAS 98–83–9

7.3 Ethyl alcohol, C2H5OH, denatured

formula 2B, CAS 64–17–5

REAGENTS:

7.4 Internal Standard Stock Solution:

5.0 mg/ml AMS in ethyl alcohol.

7.4.1 Into a 100-ml volumetric flask,

weigh 0.50 g of AMS to the nearest

0.1 mg.

7.4.2 Dilute to the mark with ethyl

alcohol. This solution will contain

5.0 mg/ml AMS in ethyl alcohol

and will be labeled the AMS

STOCK SOLUTION.

7.5 Internal Standard Working

Solution: 2500 ug/50 ml of AMS in

ethyl alcohol.

7.5.1 Using a 10 ml volumetric

pipet, quantitatively transfer 10.0

ml of the AMS STOCK SOLUTION

into a 1000-ml volumetric flask.

7.5.2 Dilute to the mark with ethyl

alcohol. This solution will contain

2500 ug/50ml of AMS in ethyl

alcohol and will be labeled the

AMS WORKING SOLUTION.

7.5.3 Transfer the AMS WORKING

SOLUTION to the automatic

dispensing pipet reservoir.

7.6 Styrene Stock Solution: 5.0 mg/ml

styrene in ethyl alcohol.

7.6.1 Into a 100-ml volumetric flask,

weigh 0.50 g of styrene to the

nearest 0.1 mg.

7.6.2 Dilute to the mark with ethyl

alcohol. This solution will contain

5.0 mg/ml styrene in ethyl alcohol

and will be labeled the STYRENE

STOCK SOLUTION.

7.7 Styrene Working Solution: 5000

ug/10 ml of styrene in ethyl alcohol.

7.7.1 Using a 10-ml volumetric

pipet, quantitatively transfer 10.0

ml of the STYRENE STOCK

SOLUTION into a 100-ml

volumetric flask.

7.7.2 Dilute to the mark with ethyl

alcohol. This solution will contain

5000 ug/10 ml of styrene in ethyl

alcohol and will be labeled the

STYRENE WORKING SOLUTION.

8.0 Sample Collection, Preservation

and Storage

8.1 Label a 2-oz sample poly-cap lid

with the identity, date and time of

the sample to be obtained.

8.2 At the sample location, open

sample valve for at least 15 seconds

to ensure that the sampling pipe has

been properly flushed with fresh

sample.

8.3 Fill the sample jar to the top (no

headspace) with sample, then cap it

tightly.

8.4 Deliver sample to the Laboratory

for testing within one hour of

sampling.

8.5 Laboratory testing will be done

within two hours of the sampling

time.

8.6 No special storage conditions are

required unless the storage time
Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations 12557

exceeds 2 hours in which case

refrigeration of the sample is

recommended.

9.0 Quality Control

9.1 For each sample type, 12 samples

of SBR latex shall be obtained from

the process for the recovery study.

Half the vials and caps shall be

tared, labeled ‘‘spiked’’, and

numbered 1 through 6. The other

vials are labeled ‘‘unspiked’’ and

need not be tared, but are also

numbered 1 through 6.

9.2 The six vials labeled ‘‘spiked’’

shall be spiked with an amount of

styrene to approximate 50% of the

solution’s expected residual styrene

level.

9.3 The spiked samples shall be

shaken for several hours and

allowed to cool to room

temperature before analysis.

9.4 The six samples of unspiked

solution shall be coagulated and a

mean styrene value shall be

determined, along with the

standard deviation, and the percent

relative standard deviation.

9.5 The six samples of the spiked

solution shall be coagulated and the

results of the analyses shall be

determined using the following

equations:

Mr=Ms¥Mu

R=Mr/S

where:

Mu=Mean value of styrene in the

unspiked sample

Ms=Measured amount of styrene in the

spiked sample

Mr=Measured amount of the spiked

compound

S=Amount of styrene added to the

spiked sample

R=Fraction of spiked styrene recovered

9.6 A value of R between 0.70 and 1.30

is acceptable.

9.7 R is used to correct all reported

results for each compound by

dividing the measured results of

each compound by the R for that

compound for the same sample

type.

10.0 Calibration

10.1 Using a 10-ml volumetric pipet,

quantitatively transfer 10.0 ml of

the STYRENE WORKING

SOLUTION (section 7.7.2 of this

method) into a 2-oz bottle.

10.2 Using the AMS WORKING

SOLUTION equipped with the

automatic dispensing pipet (section

7.5.3 of this method), transfer 50.0

ml of the internal standard solution

into the 2-oz bottle.

10.3 Cap the 2-oz bottle and swirl.

This is the calibration standard,

which contains 5000 μg of styrene

and 2500 μg of AMS.

10.4 Using the conditions prescribed

(section 6.5 of this method),

chromatograph 1 μl of the

calibration standard.

10.5 Obtain the peak areas and

calculate the relative response

factor as described in the

calculations section (section 12.1 of

this method).

11.0 Procedure

11.1 Into a tared 2-oz bottle, weigh

10.0 g of latex to the nearest 0.1 g.

11.2 Using the AMS WORKING

SOLUTION equipped with the

automatic dispensing pipet (section

7.5.3 of this method), transfer 50.0

ml of the internal standard solution

into the 2-oz bottle.

11.3 Cap the bottle. Using a

mechanical shaker, shake the bottle

for at least one minute or until

coagulation of the latex is complete

as indicated by a clear solvent.

11.4 Using the conditions prescribed

(section 6.5 of this method),

chromatograph 1 ul of the liquor.

11.5 Obtain the peak areas and

calculate the concentration of

styrene in the latex as described in

the calculations section (Section

12.2 of this method).

12.0 Calculations

12.1 Calibration:

RF=(Wx×Ais) / (Wis×Ax)

where:

RF=the relative response factor for

styrene

Wx=the weight (ug) of styrene

Ais=the area of AMS

Wis=the weight (ug) of AMS

Ax=the area of styrene

12.2 Procedure:

ppmstyrene=(AxRF×Wis) / (Ais×Ws)

where:

ppmstyrene=parts per million of styrene in

the latex

Ax=the area of styrene

RF=the response factor for styrene

Wis=the weight (ug) of AMS

Ais=the area of AMS

Ws=the weight (g) of the latex sample

12.3 Correct for recovery (R) as

determined by section 9.0 of this

method.

13.0 Precision

13.1 Precision for the method was

determined at the 80, 144, 590, and

1160 ppm levels. The standard

deviations were 0.8, 1.5, 5 and 9

ppm respectively. The percent

relative standard deviations

(%RSD) were 1% or less at all

levels. Five degrees of freedom were

used for all precision data except at

the 80 ppm level, where nine

degrees of freedom were used. Note:

These are example results and do

not replace quality assurance

procedures in this method.

14.0 Pollution Prevention

14.1 Waste generation should be

minimized where possible. Sample

size should be an amount necessary

to adequately run the analysis.

15.0 Waste Management

15.1 Discard liquid chemical waste

into the chemical waste drum.

15.2 Discard latex sample waste into

the latex waste drum.

15.3 Discard polymer waste into the

polymer waste container.

16.0 References

16.1 This method is based on

Goodyear Chemical Division Test

Method E–889.

METHOD 312C—DETERMINATION OF

RESIDUAL STYRENE IN SBR LATEX

PRODUCED BY EMULSION

POLYMERIZATION

1.0 Scope

1.1 This method is applicable for

determining the amount of residual

styrene in SBR latex as produced in

the emulsion polymerization

process.

2.0 Principle of Method

2.1 A weighed sample of latex is

coagulated in 2-propanol which

contains alpha-methyl styrene as an

Internal Standard. The extract from

the coagulation will contain the

alpha-methyl styrene as the Internal

Standard and the residual styrene

from the latex. The extract is

analyzed by a Gas Chromatograph.

Percent styrene is calculated by

relating the area of the styrene peak

to the area of the Internal Standard

peak of known concentration.

3.0 Definitions

3.1 The definitions are included in the

text as needed.

4.0 Interferences

(Reserved)

5.0 Safety

5.1 When using solvents, avoid contact

with skin and eyes. Wear hand and

eye protection. Wash thoroughly

after use.

5.2 Avoid overexposure to solvent

vapors. Handle only in well

ventilated areas.
12558 Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations

6.0 Equipment and Supplies

6.1 Gas Chromatograph—Hewlett

Packard 5890, Series II with flame

ionization detector, or equivalent.

Column—HP 19095F–123, 30m ×

0.53mm, or equivalent. Substrate

HP FFAP (cross-linked) film

thickness 1 micrometer. Glass

injector port liners with silanized

glass wool plug.

Integrator—HP 3396, Series II, or

equivalent.

6.2 Wrist action shaker

6.3 Automatic dispenser

6.4 Automatic pipet, calibrated to

deliver 5.0 ±0.01 grams of latex

6.5 Four-ounce wide-mouth bottles

with foil lined lids

6.6 Crimp cap vials, 2ml, teflon lined

septa

6.7 Disposable pipets

6.8 Qualitative filter paper

6.9 Cap crimper

6.10 Analytical balance

6.11 10ml pipette

6.12 Two-inch funnel

7.0 Reagents and Standards

7.1 2-Propanol (HP2C grade)

7.2 Alpha methyl styrene (99+%

purity)

7.3 Styrene (99+% purity)

7.4 Zero air

7.5 Hydrogen (chromatographic grade)

7.6 Helium

7.7 Internal Standard preparation

7.7.1 Weigh 5.000–5.005 grams of

alpha-methyl styrene into a 100ml

volumetric flask and bring to mark

with 2-propanol to make Stock ‘‘A’’

Solution.

Note: Shelf life—6 months.

7.7.2 Pipette 10ml of Stock ‘‘A’’

Solution into a 100ml volumetric

flask and bring to mark with 2-

propanol to prepare Stock ‘‘B’’

Solution.

7.7.3 Pipette 10ml of the Stock ‘‘B’’

solution to a 1000ml volumetric

flask and bring to the mark with 2-

propanol. This will be the Internal

Standard Solution (0.00005 grams/

ml).

7.8 Certification of Internal Standard—

Each batch of Stock ‘‘B’’ Solution

will be certified to confirm

concentration.

7.8.1 Prepare a Standard Styrene

Control Solution in 2-propanol by

the following method:

7.8.1.1 Weigh 5.000 ±.005g of

styrene to a 100ml volumetric flask

and fill to mark with 2-propanol to

make Styrene Stock ‘‘A’’ Solution.

7.8.1.2 Pipette 10ml of Styrene Stock

‘‘A’’ Solution to a 100ml volumetric

flask and fill to mark with 2-

propanol to make Styrene Stock

‘‘B’’ Solution.

7.8.1.3 Pipette 10ml of Styrene Stock

‘‘B’’ soluion to a 250ml volumtric

flask and fill to mark wtih 2-

propanol to make the Certification

Solution.

7.8.2 Certify Alpha-Methyl Styrene

Stock ‘‘B’’ Solution.

7.8.2.1 Pipette 5ml of the

Certification Solution and 25ml of

the Alpha Methyl Styrene Internal

Standard Solution to a 4-oz. bottle,

cap and shake well.

7.8.2.2 Analyze the resulting

mixture by GC using the residual

styrene method. (11.4–11.6 of this

method)

7.8.2.3 Calculate the weight of alpha

methyl styrene present in the 25ml

aliquat of the new Alpha Methyl

Styrene Standard by the following

equation:

Wx = FxxWis(Ax/Ais)

Where

Ax = Peak area of alpha methyl styrene

Ais = Peak area of styrene

Wx = Weight of alpha methyl styrene

Wis = Weight of styrene (.00100)

Fx = Analyzed response factor = 1

The Alpha Methyl Styrene Stock

Solution used to prepare the Internal

Standard Solution may be considered

certified if the weight of alpha methyl

styrene analyzed by this method is

within the range of .00121g to .00129g.

8.0 Sampling

8.1 Collect a latex sample in a capped

container. Cap the bottle and

identify the sample as to location

and time.

8.2 Deliver sample to Laboratory for

testing within one hour.

8.3 Laboratory will test within two

hours.

8.4 No special storage conditions are

required.

9.0 Quality Control

9.1 The laboratory is required to

operate a formal quality control

program. This consists of an initial

demonstration of the capability of

the method as well as ongoing

analysis of standards, blanks, and

spiked samples to demonstrate

continued performance.

9.1.1 When the method is first set

up, a calibration is run and the

recovery efficiency for each type of

sample must be determined.

9.1.2 If new types of samples are

being analyzed, then recovery

efficiency for each new type of

sample must be determined. New

type includes any change, such as

polymer type, physical form or a

significant change in the

composition of the matrix.

9.2 Recovery efficiency must be

determined once for each sample

type and whenever modifications

are made to the method.

9.2.1 In determining the recovery

efficiency, the quadruplet sampling

system shall be used. Six sets of

samples (for a total of 24) shall be

taken. In each quadruplet set, half

of the samples (two out of the four)

shall be spiked with styrene.

9.2.2 Prepare the samples as described

in section 8 of this method. To the

vials labeled ‘‘spiked’’, add a

known amount of styrene that is

expected to be present in the latex.

9.2.3 Run the spiked and unspiked

samples in the normal manner.

Record the concentrations of

styrene reported for each pair of

spiked and unspiked samples with

the same vial number.

9.2.4 For each hydrocarbon, calculate

the average recovery efficiency (R)

using the following equation:

R=Σ(Rn)/12

Where: n = sample number

Rn=(Ms¥Mu)/S

Ms=total mass of compound (styrene)

measured in spiked sample (μg)

Mu=total mass of compound (styrene)

measured in unspiked sample (μg)

S=theoretical mass of compound

(styrene) spiked into sample (μg)

R=fraction of spiked compound

(styrene) recovered

9.2.5 A different R value should be

obtained for each sample type. A

value of R between 0.70 and 1.30 is

acceptable.

9.2.6 R is used to correct all reported

results for each compound by

dividing the measured results of

each compound by the R for that

compound for the same sample

type.

10.0 Calibration

A styrene control sample will be

tested weekly to confirm the FID

response and calibration.

10.1 Using the Styrene Certification

Solution prepared in 7.8.1, perform

test analysis as described in 7.8.2

using the equation in 7.8.2.3 to

calculate results.

10.2 Calculate the weight of styrene in

the styrene control sample using the

following equation:

Wsty=(FxxAstyxWis)Ais

The instrument can be considered

calibrated if the weight of the styrene

analyzed is within range of 0.00097—

0.00103gms.
Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations 12559

11.0 Procedure

11.1 Using an auto pipet, add 25ml of

Internal Standard Solution to a 4 oz.

wide-mouth bottle.

11.2 Using a calibrated auto pipet, add

5.0 ± 0.01g latex to the bottle

containing the 25ml of Internal

Standard Solution.

11.3 Cap the bottle and place on the

wrist action shaker. Shake the

sample for a minimum of five

minutes using the timer on the

shaker. Remove from shaker.

11.4 Using a disposable pipet, fill the

2ml sample vial with the clear

alcohol extract. (If the extract is not

clear, it should be filtered using a

funnel and filter paper.) Cap and

seal the vial.

11.5 Place the sample in the

autosampler tray and start the GC

and Integrator. The sample will be

injected into the GC by the autoinjector, and the Integrator will

print the results.

11.6 Gas Chromatograph Conditions

Oven Temp—70 °C

Injector Temp—225 °C

Detector Temp—275 °C

Helium Pressure—500 KPA

Column Head Pressure—70 KPA

Makeup Gas—30 ml/min.

Column—HP 19095F—123, 30m x

0.53mm Substrate: HP—FFAP

(cross-linked) 1 micrometer film

thickness

12.0 Calculations

12.1 The integrator is programmed to

do the following calculation at the

end of the analysis:

%ResidualStyrene=(AxXWis)/

(AisXWx)XFxX100

Where:

Ax=Peak area of styrene

Ais=Peak area of internal standard

Wx=Weight of sample = 5g

Wis=Weight of internal std. = 0.00125g

Fx=Analyzed response factor = 1.0

12.2 The response factor is determined

by analyzing a solution of 0.02g of

styrene and 0.02g of alpha methyl

styrene in 100ml of 2-propanol.

Calculate the factor by the following

equation:

Fx=(WxxAis)/(WisxAx)

Where:

Wx=Weight of styrene

Ax=Peak area of styrene

Wis=Weight of alpha methyl styrene

Ais=Peak area of alpha methyl styrene

13.0 Method Performance

13.1 Performance must be determined

for each sample type by following

the procedures in section 9 of this

method.

14.0 Waste Generation

14.1 Waste generation should be

minimized where possible.

15.0 Waste Management

15.1 All waste shall be handled in

accordance with Federal and State

environmental regulations.

16.0 References

(Reserved)

METHOD 313A—DETERMINATION

OF RESIDUAL HYDROCARBONS IN

RUBBER CRUMB

1.0 Scope and Application

1.1 This method determines residual

toluene and styrene in stripper crumb of

the of the following types of rubber:

polybutadiene (PBR) and styrene/

butadiene rubber (SBR), both derived

from solution polymerization processes

that utilize toluene as the

polymerization solvent.

1.2 The method is applicable to a

wide range of concentrations of toluene

and styrene provided that calibration

standards cover the desired range. It is

applicable at least over the range of 0.01

to 10.0 % residual toluene and from 0.1

to 3.0 % residual styrene. It is probably

applicable over a wider range, but this

must be verified prior to use.

1.3 The method may also be

applicable to other process samples as

long as they are of a similar composition

to stripper crumb. See section 3.1 of this

method for a description of stripper

crumb.

2.0 Summary of Method

2.1 The wet crumb is placed in a

sealed vial and run on a headspace

sampler which heats the vial to a

specified temperature for a specific time

and then injects a known volume of

vapor into a capillary GC. The

concentration of each component in the

vapor is proportional to the level of that

component in the crumb sample and

does not depend on water content of the

crumb.

2.2 Identification of each component

is performed by comparing the retention

times to those of known standards.

2.3 Results are calculated by the

external standard method since

injections are all performed in an

identical manner. The response for each

component is compared with that

obtained from dosed samples of crumb.

2.4 Measured results of each

compound are corrected by dividing

each by the average recovery efficiency

determined for the same compound in

the same sample type.

3.0 Definitions

3.1 Stripper crumb refers to pieces

of rubber resulting from the steam

stripping of a toluene solution of the

same polymer in a water slurry. The

primary component of this will be

polymer with lesser amounts of

entrained water and residual toluene

and other hydrocarbons. The amounts of

hydrocarbons present must be such that

the crumb is a solid material, generally

less that 10 % of the dry rubber weight.

4.0 Interferences

4.1 Contamination is not normally a

problem since samples are sealed into

vials immediately on sampling.

4.2 Cross contamination in the

headspace sampler should not be a

problem if the correct sampler settings

are used. This should be verified by

running a blank sample immediately

following a normal or high sample.

Settings may be modified if necessary if

this proves to be a problem, or a blank

sample may be inserted between

samples.

4.3 Interferences may occur if

volatile hydrocarbons are present which

have retention times close to that of the

components of interest. Since the

solvent makeup of the processes

involved are normally fairly well

defined this should not be a problem. If

it is found to be the case, switching to

a different chromatographic column will

probably resolve the situation.

5.0 Safety

5.1 The chemicals specified in this

method should all be handled according

to standard laboratory practices as well

as any special precautions that may be

listed in the MSDS for that compound.

5.2 Sampling of strippers or other

process streams may involve high

pressures and temperatures or may have

the potential for exposure to chemical

fumes. Only personnel who have been

trained in the specific sampling

procedures required for that process

should perform this operation. An

understanding of the process involved is

necessary. Proper personal protective

equipment should be worn. Any

sampling devices should be inspected

prior to use. A detailed sampling

procedure which specifies exactly how

to obtain the sample must be written

and followed.

6.0 Equipment and Supplies

6.1 Hewlett Packard (HP) 7694

Headspace sampler, or equivalent, with

the following conditions:

Times (min.): GC cycle time 6.0 , vial

equilibration 30.0 , pressurization

0.25 , loop fill 0.25, loop

equilibration 0.05 , inject 0.25

Temperatures (deg C): oven 70, loop 80,

transfer line 90

Pressurization gas: He @ 16 psi
12560 Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations

6.2 HP 5890 Series II capillary gas

chromatograph, or equivalent, with the

following conditions:

Column: Supelco SPB–1, or equivalent,

15m × .25mm × .25μ film

Carrier: He @ 6 psi

Run time: 4 minutes

Oven: 70 deg C isothermal

Injector: 200 deg C split ratio 50:1

Detector: FID @ 220 deg C

6.3 HP Chemstation consisting of

computer, printer and Chemstation

software, or an equivalent

chromatographic data system.

6.4 20 ml headspace vials with caps

and septa.

6.5 Headspace vial crimper.

6.6 Microliter pipetting syringes.

6.7 Drying oven at 100 deg C vented

into cold trap or other means of trapping

hydrocarbons released.

6.8 Laboratory shaker or tumbler

suitable for the headspace vials.

6.9 Personal protective equipment

required for sampling the process such

as rubber gloves and face and eye

protection.

7.0 Reagents and Standards

7.1 Toluene, 99.9+% purity, HPLC

grade.

7.2 Styrene, 99.9+% purity, HPLC

grade.

7.3 Dry rubber of same type as the

stripper crumb samples.

8.0 Sample Collection, Preservation

and Storage

8.1 Collect a sample of crumb in a

manner appropriate for the process

equipment being sampled.

8.1.1 If conditions permit, this may

be done by passing a stream of the

crumb slurry through a strainer, thus

separating the crumb from the water.

Allow the water to drain freely, do not

attempt to squeeze any water from the

crumb. Results will not depend on the

exact water content of the samples.

Immediately place several pieces of

crumb directly into a headspace vial.

This should be done with rubber gloves

to protect the hands from both the heat

and from contact with residual

hydrocarbons. The vial should be

between 1⁄4 and 1⁄3 full. Results do not

depend on sample size as long as there

is sufficient sample to reach an

equilibrium vapor pressure in the

headspace of the vial. Cap and seal the

vial. Prepare each sample at least in

duplicate. This is to minimize the effect

of the variation that naturally occurs in

the composition of non homogeneous

crumb. The free water is not analyzed

by this method and should be disposed

of appropriately along with any unused

rubber crumb.

8.1.2 Alternatively the process can

be sampled in a specially constructed

sealed bomb which can then be

transported to the laboratory. The bomb

is then cooled to ambient temperature

by applying a stream of running water.

The bomb can then be opened and the

crumb separated from the water and the

vials filled as described in section 8.1.1

of this method. The bomb may be stored

up to 8 hours prior to transferring the

crumb into vials.

8.2 The sealed headspace vials may

be run immediately or may be stored up

to 72 hours prior to running. It is

possible that even longer storage times

may be acceptable, but this must be

verified for the particular type of sample

being analyzed (see section 9.2.3 of this

method). The main concern here is that

some types of rubber eventually may

flow, thus compacting the crumb so that

the surface area is reduced. This may

have some effect on the headspace

equilibration.

9.0 Quality Control

9.1 The laboratory is required to

operate a formal quality control

program. This consists of an initial

demonstration of the capability of the

method as well as ongoing analysis of

standards, blanks and spiked samples to

demonstrate continued performance.

9.1.1 When the method is first set up

a calibration is run (described in section

10 of this method) and an initial

demonstration of method capability is

performed (described in section 9.2 of

this method). Also recovery efficiency

for each type of sample must be

determined (see section 9.4 of this

method).

9.1.2 It is permissible to modify this

method in order to improve separations

or make other improvements, provided

that all performance specifications are

met. Each time a modification to the

method is made it is necessary to repeat

the calibration (section 10 of this

method), the demonstration of method

performance (section 9.2 of this method)

and the recovery efficiency for each type

of sample (section 9.4 of this method).

9.1.3 Ongoing performance should

be monitored by running a spiked

rubber standard. If this test fails to

demonstrate that the analysis is in

control, then corrective action must be

taken. This method is described in

section 9.3 of this method.

9.1.4 If new types of samples are

being analyzed then recovery efficiency

for each new type of sample must be

determined. New type includes any

change, such as polymer type, physical

form or a significant change in the

composition of the matrix.

9.2 Initial demonstration of method

capability to establish the accuracy and

precision of the method. This is to be

run following the calibration described

in section 10 of this method.

9.2.1 Prepare a series of identical

spiked rubber standards as described in

section 9.3 of this method. A sufficient

number to determine statistical

information on the test should be run.

Ten may be a suitable number,

depending on the quality control

methodology used at the laboratory

running the tests. These are run in the

same manner as unknown samples (see

section 11 of this method).

9.2.2 Determine mean and standard

deviation for the results. Use these to

determine the capability of the method

and to calculate suitable control limits

for the ongoing performance check

which will utilize the same standards.

9.2.3 Prepare several additional

spiked rubber standards and run 2 each

day to determine the suitability of

storage of the samples for 24, 48 and 72

hours or longer if longer storage times

are desired.

9.3 A spiked rubber standard should

be run on a regular basis to verify

system performance. This would

probably be done daily if samples are

run daily. This is prepared in the same

manner as the calibration standards

(section 10.1 of this method), except

that only one concentration of toluene

and styrene is prepared. Choose

concentrations of toluene and styrene

that fall in the middle of the range

expected in the stripper crumb and then

do not change these unless there is a

major change in the composition of the

unknowns. If it becomes necessary to

change the composition of this standard

the initial performance demonstration

must be repeated with the new standard

(section 9.2 of this method).

9.3.1 Each day prepare one spiked

rubber standard to be run the following

day. The dry rubber may be prepared in

bulk and stored for any length of time

consistent with the shelf life of the

product. The addition of water and

hydrocarbons must be performed daily

and all the steps described under

section 10.1 of this method must be

followed.

9.3.2 Run the spiked rubber

standard prepared the previous day.

Record the results and plot on an

appropriate control chart or other means

of determining statistical control.

9.3.3 If the results for the standard

indicate that the test is out of control

then corrective action must be taken.

This may include a check on

procedures, instrument settings,

maintenance or recalibration. Samples

may be stored (see section 8.2 of this
Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations 12561

method) until compliance is

demonstrated.

9.4 Recovery efficiency must be

determined once for each sample type

and whenever modifications are made

to the method.

9.4.1 For each sample type collect

12 samples from the process (section 8.1

of this method). This should be done

when the process is operating in a

normal manner and residual

hydrocarbon levels are in the normal

range. Half the vials and caps should be

tared, labeled ‘‘spiked’’ and numbered 1

through 6. The other vials are labeled

‘‘unspiked’’ and need not be tared but

are also numbered 1 through 6.

Immediately on sampling, the vials

should be capped to prevent loss of

volatiles. Allow all the samples to cool

completely to ambient temperature.

Reweigh each of the vials labeled

‘‘spiked’’ to determine the weight of wet

crumb inside.

9.4.2 The dry weight of rubber

present in the wet crumb is estimated by

multiplying the weight of wet crumb by

the fraction of nonvolatiles typical for

the sample. If this is not known, an

additional quantity of crumb may be

sampled, weighed, dried in an oven and

reweighed to determine the fraction of

volatiles and nonvolatiles prior to

starting this procedure.

9.4.3 To the vials labeled ‘‘spiked’’

add an amount of a mixture of toluene

and styrene that is between 40 and 60

% of the amount expected in the crumb.

This is done by removing the cap,

adding the mixture by syringe, touching

the tip of the needle to the sample in

order to remove the drop and then

immediately recapping the vials. The

mixture is not added through the

septum, because a punctured septum

may leak and vent vapors as the vial is

heated. The weights of toluene and

styrene added may be calculated from

the volumes of the mixture added, its

composition and density, or may be

determined by the weight of the vials

and caps prior to and after addition. The

exact dry weight of rubber present and

the concentration of residual toluene

and styrene are not known at this time

so an exact calculation of the

concentration of hydrocarbons is not

possible until the test is completed.

9.4.4 Place all the vials onto a shaker

or tumbler for 24 ± 2 hours. This is

essential in order for the hydrocarbons

to be evenly distributed and completely

absorbed into the rubber. If this is not

followed the toluene and styrene will be

mostly at the surface of the rubber and

high results will be obtained.

9.4.5 Remove the vials from the

shaker and tap them so that all the

crumb settles to the bottom of the vials.

Allow them to stand for 1 hour prior to

analysis to allow any liquid to drain

fully to the bottom.

9.4.6 Run the spiked and unspiked

samples in the normal manner. Record

the concentrations of toluene and

styrene reported for each pair of spiked

and unspiked samples with the same

vial number.

9.4.7 Open each of the vials labeled

‘‘spiked’’, remove all the rubber crumb

and place it into a tarred drying pan.

Place in a 100 deg C oven for two hours,

cool and reweigh. Subtract the weight of

the tare to give the dry weight of rubber

in each spiked vial. Calculate the

concentration of toluene and styrene

spiked into each vial as percent of dry

rubber weight. This will be slightly

different for each vial since the weights

of dry rubber will be different.

9.4.8 For each hydrocarbon calculate

the average recovery efficiency (R) using

the following equations:

R=RlΣ (Ρn

)/6 (average of the 6 individual Rn

values)

Where:

Rn

=(Cns—Cnu) / Sn

Where:

n=vial number

Cns=concentration of compound

measured in spiked sample number

n.

Cnu=concentration of compound

measured in unspiked sample

number n.

Sn=theoretical concentration of

compound spiked into sample n

calculated in step 9.4.7

9.4.9 A different R value should be

obtained for each compound (styrene

and toluene) and for each sample type.

9.4.10 A value of R between 0.70

and 1.30 is acceptable.

9.4.11 R is used to correct all

reported results for each compound by

dividing the measured results of each

compound by the R for that compound

for the same sample type (see section

12.2 of this method.)

10.0 Calibration

10.1 Calibration standards are

prepared by dosing known amounts of

the hydrocarbons of interest into vials

containing known amounts of rubber

and water.

10.1.1 Cut a sufficient quantity of

dry rubber of the same type as will be

analyzed into pieces about the same size

as that of the crumb. Place these in a

single layer on a piece of aluminum foil

or other suitable surface and place into

a forced air oven at 100° C for four

hours. This is to remove any residual

hydrocarbons that may be present. This

step may be performed in advance.

10.1.2 Into each of a series of vials

add 3.0 g of the dry rubber.

10.1.3 Into each vial add 1.0 ml

distilled water or an amount that is

close to the amount that will be present

in the unknowns. The exact amount of

water present does not have much effect

on the analysis, but it is necessary to

have a saturated environment. The

water will also aid in the uniform

distribution of the spiked hydrocarbons

over the surface of the rubber after the

vials are placed on the shaker (in step

10.1.5 of this method).

10.1.4 Into each vial add varying

amounts of toluene and styrene by

microliter syringe and cap the vials

immediately to prevent loss. The tip of

the needle should be carefully touched

to the rubber in order to transfer the last

drop to the rubber. Toluene and styrene

may first be mixed together in suitable

proportions and added together if

desired. The weights of toluene and

styrene added may be calculated from

the volumes of the mixture added, its

composition and density, or may be

determined by the weight of the vials

and caps prior to and after addition.

Concentrations of added hydrocarbons

are calculated as percent of the dry

rubber weight. At least 5 standards

should be prepared with the amounts of

hydrocarbons added being calculated to

cover the entire range possible in the

unknowns. Retain two samples with no

added hydrocarbons as blanks.

10.1.5 Place all the vials onto a

shaker or tumbler for 24 ± 2 hours. This

is essential in order for the

hydrocarbons to be evenly distributed

and completely absorbed into the

rubber. If this is not followed the

toluene and styrene will be mostly at

the surface of the rubber and high

results will be obtained.

10.1.6 Remove the vials from the

shaker and tap them so that all the

crumb settles to the bottom of the vials.

Allow them to stand for 1 hour prior to

analysis to allow any liquid to drain

fully to the bottom.

10.2 Run the standards and blanks

in the same manner as described for

unknowns (section 11 of this method),

starting with a blank, then in order of

increasing hydrocarbon content and

ending with the other blank.

10.3 Verify that the blanks are

sufficiently free from toluene and

styrene or any interfering hydrocarbons.

10.3.1 It is possible that trace levels

may be present even in dry product. If

levels are high enough that they will

interfere with the calibration then the

drying procedure in section 10.1.1 of

this method should be reviewed and

modified as needed to ensure that

suitable standards can be prepared.

10.3.2 It is possible that the final

blank is contaminated by the previous
12562 Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations

standard. If this is the case review and

modify the sampler parameters as

needed to eliminate this problem. If

necessary it is possible to run blank

samples between regular samples in

order to reduce this problem, though it

should not be necessary if the sampler

is properly set up.

10.4 Enter the amounts of toluene

and styrene added to each of the

samples (as calculated in section 10.1.4

of this method) into the calibration table

and perform a calibration utilizing the

external standard method of analysis.

10.5 At low concentrations the

calibration should be close to linear. If

a wide range of levels are to be

determined it may be desirable to apply

a nonlinear calibration to get the best fit.

11.0 Procedure

11.1 Place the vials in the tray of the

headspace sampler. Enter the starting

and ending positions through the

console of the sampler. For unknown

samples each is run in duplicate to

minimize the effect of variations in

crumb composition. If excessive

variation is noted it may be desirable to

run more than two of each sample.

11.2 Make sure the correct method is

loaded on the Chemstation. Turn on the

gas flows and light the FID flame.

11.3 Start the sequence on the

Chemstation. Press the START button

on the headspace unit. The samples will

be automatically injected after

equilibrating for 30 minutes in the oven.

As each sample is completed the

Chemstation will calculate and print out

the results as percent toluene and

styrene in the crumb based on the dry

weight of rubber.

12.0 Data Analysis and Calculations

12.1 For each set of duplicate

samples calculate the average of the

measured concentration of toluene and

styrene. If more than two replicates of

each sample are run calculate the

average over all replicates.

12.2 For each sample correct the

measured amounts of toluene and

styrene using the following equation:

Corrected Result = Cm/R

Where:

Cm = Average measured concentration

for that compound.

R = Recovery efficiency for that

compound in the same sample type

(see section 9.4 of this method)

12.3 Report the recovery efficiency

(R) and the corrected results of toluene

and styrene for each sample.

13.0 Method Performance

13.1 This method can be very

sensitive and reproducible. The actual

performance depends largely on the

exact nature of the samples being

analyzed. Actual performance must be

determined by each laboratory for each

sample type.

13.2 The main source of variation is

the actual variation in the composition

of non homogeneous crumb in a

stripping system and the small sample

sizes employed here. It therefore is the

responsibility of each laboratory to

determine the optimum number of

replicates of each sample required to

obtain accurate results.

14.0 Pollution Prevention

14.1 Samples should be kept sealed

when possible in order to prevent

evaporation of hydrocarbons.

14.2 When drying of samples is

required it should be done in an oven

which vents into a suitable device that

can trap the hydrocarbons released.

14.3 Dispose of samples as described

in section 15.

15.0 Waste Management

15.1 Excess stripper crumb and

water as well as the contents of the used

sample vials should be properly

disposed of in accordance with local

and federal regulations.

15.2 Preferably this will be

accomplished by having a system of

returning unused and spent samples to

the process.

16.0 References

16.1 ‘‘HP 7694 Headspace

Sampler—Operating and Service

Manual’’, Hewlett-Packard Company,

publication number G1290–90310, June

1993.

METHOD 313B—THE

DETERMINATION OF RESIDUAL

HYDROCARBON IN SOLUTION

POLYMERS BY CAPILLARY GAS

CHROMATOGRAPHY

1.0 Scope

1.1 This method is applicable to

solution polymerized polybutadiene

(PBD).

1.2 This method quantitatively

determines n-hexane in wet crumb

polymer at levels from 0.08 to 0.15% by

weight.

1.3 This method may be extended to

the determination of other hydrocarbons

in solution produced polymers with

proper experimentation and

documentation.

2.0 Principle of Method

2.1 A weighed sample of polymer is

dissolved in chloroform and the cement

is coagulated with an isopropyl alcohol

solution containing a specific amount of

alpha-methyl styrene (AMS) as the

internal standard. The extract of this

coagulation is then injected into a gas

chromatograph and separated into

individual components. Quantification

is achieved by the method of internal

standardization.

3.0 Definitions

3.1 The definitions are included in

the text as needed.

4.0 Interferences

(Reserved)

5.0 Safety

5.1 This method may involve

hazardous materials, operations, and

equipment. This method does not

purport to address all of the safety

problems associated with its use. It is

the responsibility of the user of this

method to establish appropriate safety

and health practices and determine the

applicability of regulatory limitations

prior to use.

6.0 Equipment and Supplies

6.1 Analytical balance, 160 g capacity,

0.1 mg resolution

6.2 Bottles, 2-oz capacity with polycap screw lids

6.3 Mechanical shaker

6.4 Syringe, 10–ul capacity

6.5 Syringe, 2.5–ml capacity, with 22

gauge 1.25 inch needle, PP/PE

material, disposable

6.6 Gas chromatograph, HewlettPackard model 5890, or equivalent,

configured with FID, split injector

packed with silanized glass wool.

6.6.1 Establish the following gas

chromatographic conditions, and

allow the system to thoroughly

equilibrate before use.

6.6.2 Injector parameters:

Injection technique=Split

Injector split flow=86 ml/min

Injector temperature=225 deg C

6.6.3 Oven temperature program:

Initial temperature=40 deg C

Initial time=6 min

Program rate=10 deg C/min

Upper limit temperature=175 deg C

Upper limit interval=10 min

6.6.4 Detector parameters:

Detector temperature=300 deg C

Hydrogen flow=30 ml/min

Air flow=350 ml/min

Nitrogen make up=26 ml/min

6.7 Gas chromatographic columns: SE–

54 (5%-phenyl) (1%-vinyl)-

methylpolysiloxane, 15 M×0.53 mm

ID with a 1.2 micron film thickness,

and a Carbowax 20M (polyethylene

glycol), 15 M×0.53 mm ID with a

1.2 micron film thickness.

6.7.1 Column assembly: using a 0.53

mm ID butt connector union, join

the 15 M×0.53 mm SE–54 column
Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations 12563

to the 15 M×0.53 mm Carbowax

20M. The SE–54 column will be

inserted into the injector and the

Carbowax 20M inserted into the

detector after they have been joined.

6.7.2 Column parameters:

Helium flow=2.8 ml/min

Helium headpressure=2 psig

6.8 Centrifuge

6.9 Data collection system, HewlettPackard Model 3396, or equivalent

6.10 Pipet, 25–ml capacity, automatic

dispensing, and 2 liter reservoir

6.11 Pipet, 2–ml capacity, volumetric

delivery, class A

6.12 Flasks, 100 and 1000-ml capacity,

volumetric, class A

6.13 Vial, serum, 50-ml capacity, red

rubber septa and crimp ring seals

6.14 Sample collection basket

fabricated out of wire mesh to allow

for drainage

7.0 Chemicals and Reagents

CHEMICALS:

7.1 alpha-Methyl Styrene, C9H10,

99+% purity, CAS 98–83–9

7.2 n-Hexane, C6H14, 99+% purity,

CAS 110–54–3

7.3 Isopropyl alcohol, C3H8O 99.5+%

purity, reagent grade, CAS 67–63–0

7.4 Chloroform, CHCl3, 99% min.,

CAS 67–66–3

REAGENTS:

7.5 Internal Standard Stock Solution:

10 mg/25 ml AMS in isopropyl

alcohol.

7.5.1 Into a 25-ml beaker, weigh 0.4

g of AMS to the nearest 0.1 mg.

7.5.2 Quantitatively transfer this

AMS into a 1-L volumetric flask.

Dilute to the mark with isopropyl

alcohol.

7.5.3 Transfer this solution to the

automatic dispensing pipet

reservoir. This will be labeled the

AMS STOCK SOLUTION.

7.6 n-Hexane Stock Solution: 13mg/

2ml hexane in isopropyl alcohol.

7.6.1 Into a 100-ml volumetric flask,

weigh 0.65 g of n-hexane to the

nearest 0.1 mg.

7.6.2 Dilute to the mark with

isopropyl alcohol. This solution

will be labeled the n-HEXANE

STOCK SOLUTION.

8.0 Sample Collection, Preservation

and Storage

8.1 A sampling device similar to

Figure 1 is used to collect a nonvented crumb rubber sample at a

location that is after the stripping

operation but before the sample is

exposed to the atmosphere.

8.2 The crumb rubber is allowed to

cool before opening the sampling

device and removing the sample.

8.3 The sampling device is opened and

the crumb rubber sample is

collected in the sampling basket.

8.4 One pound of crumb rubber

sample is placed into a

polyethylene bag. The bag is labeled

with the time, date and sample

location.

8.5 The sample should be delivered to

the laboratory for testing within one

hour of sampling.

8.6 Laboratory testing will be done

within 3 hours of the sampling

time.

8.7 No special storage conditions are

required unless the storage time

exceeds 3 hours in which case

refrigeration of the samples is

recommended.

9.0 Quality Control

9.1 For each sample type, 12 samples

shall be obtained from the process

for the recovery study. Half of the

vials and caps shall be tared,

labeled ‘‘spiked’’, and numbered 1

through 6. The other vials shall be

labeled ‘‘unspiked’’ and need not be

tared, but are also numbered 1

through 6.

9.2 Determine the % moisture content

of the crumb sample. After

determining the % moisture

content, the correction factor for

calculating the dry crumb weight

can be determined by using the

equation in section 12.2 of this

method.

9.3 Run the spiked and unspiked

samples in the normal manner.

Record the concentrations of the nhexane content of the mixed hexane

reported for each pair of spiked and

unspiked samples.

9.4 For the recovery study, each

sample of crumb shall be dissolved

in chloroform containing a known

amount of mixed hexane solvent.

9.5 For each hydrocarbon, calculate

the recovery efficiency (R) using the

following equations:

Mr=Ms¥Mu

R=Mr/S

Where:

Mu=Measured amount of compound in

the unspiked sample

Ms=Measured amount of compound in

the spiked sample

Mr=Measured amount of the spiked

compound

S=Amount of compound added to the

spiked sample

R=Fraction of spiked compound

recovered

9.6 Normally a value of R between

0.70 and 1.30 is acceptable.

9.7 R is used to correct all reported

results for each compound by

dividing the measured results of

each compound by the R for that

compound for the same sample

type.

10.0 Calibration

10.1 Using the AMS STOCK

SOLUTION equipped with the

automatic dispensing pipet (7.5.3 of

this method), transfer 25.0 ml of the

internal standard solution into an

uncapped 50-ml serum vial.

10.2 Using a 2.0 ml volumetric pipet,

quantitatively transfer 2.0 ml of the

n-HEXANE STOCK SOLUTION

(7.6.2 of this method) into the 50-

ml serum vial and cap. This

solution will be labeled the

CALIBRATION SOLUTION.

10.3 Using the conditions prescribed

(6.6 of this method), inject 1 μl of

the supernate.

10.4 Obtain the peak areas and

calculate the response factor as

described in the calculations

section (12.1 of this method).

11.0 Procedure

11.1 Determination of Dry Polymer

Weight

11.1.1 Remove wet crumb from the

polyethylene bag and place on

paper towels to absorb excess

surface moisture.

11.1.2 Cut small slices or cubes from

the center of the crumb sample to

improve sample uniformity and

further eliminate surface moisture.

11.1.3 A suitable gravimetric

measurement should be made on a

sample of this wet crumb to

determine the correction factor

needed to calculate the dry polymer

weight.

11.2 Determination of n-Hexane in

Wet Crumb

11.2.1 Remove wet crumb from the

polyethylene bag and place on

paper towels to absorb excess

surface moisture.

11.2.2 Cut small slices or cubes from

the center of the crumb sample to

improve sample uniformity and

further eliminate surface moisture.

11.2.3 Into a tared 2 oz bottle, weigh

1.5 g of wet polymer to the nearest

0.1 mg.

11.2.4 Add 25 ml of chloroform to

the 2 oz bottle and cap.

11.2.5 Using a mechanical shaker,

shake the bottle until the polymer

dissolves.

11.2.6 Using the autodispensing

pipet, add 25.0 ml of the AMS

STOCK SOLUTION (7.5.3 of this

method) to the dissolved polymer

solution and cap.

11.2.7 Using a mechanical shaker,

shake the bottle for 10 minutes to
12564 Federal Register / Vol. 62, No. 51 / Monday, March 17, 1997 / Rules and Regulations

coagulate the dissolved polymer.

11.2.8 Centrifuge the sample for 3

minutes at 2000 rpm.

11.2.9 Using the conditions

prescribed (6.6 of this method),

chromatograph 1 μl of the

supernate.

11.2.10 Obtain the peak areas and

calculate the concentration of the

component of interest as described

in the calculations (12.2 of this

method).

12.0 Calculations

12.1 Calibration:

RFx=(Wx × Ais) / (Wis × Ax)

Where:

RFx=the relative response factor for nhexane

Wx=the weight (g) of n-hexane in the

CALIBRATION

SOLUTION

Ais=the area of AMS

Wis=the weight (g) of AMS in the

CALIBRATION SOLUTION

Ax=the area of n-hexane

12.2 Procedure:

12.2.1 Correction Factor for

calculating dry crumb weight.

F=1—(% moisture / 100)

Where:

F=Correction factor for calculating dry

crumb weight

% moisture determined by appropriate

method

12.2.2 Moisture adjustment for

chromatographic determination.

Ws=F × Wc

Where:

Ws=the weight (g) of the dry polymer

corrected for moisture

F=Correction factor for calculating dry

crumb weight

Wc=the weight (g) of the wet crumb in

section 9.6

12.2.3 Concentration (ppm) of

hexane in the wet crumb.

ppmx=(Ax * RFx * Wis * 10000) / (Ais *

Ws)

Where:

ppmx=parts per million of n-hexane in

the polymer

Ax=the area of n-hexane

RFx=the relative response factor for nhexane

Wis=the weight (g) of AMS in the sample

solution

Ais=the area of AMS

Ws=the weight (g) of the dry polymer

corrected for moisture

13.0 Method Performance

13.1 Precision for the method was

determined at the 0.08% level.

The standard deviation was 0.01 and

the percent relative standard deviation

(RSD) was 16.3 % with five degrees of

freedom.

14.0 Waste Generation

14.1 Waste generation should be

minimized where possible.

15.0 Waste Management

15.1 Discard liquid chemical waste

into the chemical waste drum.

15.2 Discard polymer waste into the

polymer waste container.

16.0 References

16.1 This method is based on

Goodyear Chemical Division Test

Method E–964.

[FR Doc. 97–6506 Filed 3–14–97; 8:45 am]

BILLING CODE 6560–50–P

40 CFR Part 79

[FRL–5707–7]

Registration of Fuels and Fuel

Additives: Changes in Requirements,

and Applicability to Blenders of

Deposit Control Gasoline Additives

AGENCY: Environmental Protection

Agency.

ACTION: Final rule.

SUMMARY: This action finalizes several

specific changes to existing regulations

which require the registration and

testing of designated motor vehicle fuels

and fuel additives (F/FAs) by their

manufacturers. Included are changes to

the regulatory definitions of ‘‘fuel

manufacturer,’’ ‘‘additive,’’ and ‘‘small

business,’’ as well as modifications to

grouping rules for biodiesel and

synthetic fuels. These changes will

streamline F/FA registration and testing

burdens and reduce the number of

respondents, while maintaining the

informational value of the program and

its contributions to the public health

and environmental goals of the Clean

Air Act.

Another previously proposed change,

to establish a de minimis provision for

F/FAs containing certain ‘‘atypical’’

elements, is not addressed in this

action. However, in a direct final rule

also published elsewhere in this issue of

the Federal Register, certain deadlines

related to testing of atypical F/FAs are

extended while EPA determines the

most appropriate disposition of the de

minimis proposal.

EFFECTIVE DATE: This action will be

effective on May 16, 1997.

ADDRESSES: Documents related to this

final rule have been placed in Public

Docket No. A–90–07 located at the U.S.

EPA, Air Docket Section, Room M–

1500, 401 M Street S.W., Washington,

DC 20460. The docket is open for public

inspection from 8:00 a.m. until 5:30

p.m., Monday through Friday, except on

Federal holidays. A reasonable fee may

be charged for photocopying.

FOR FURTHER INFORMATION CONTACT: Jim

Caldwell (202–233–9303) or Joseph

Fernandes (202–233–9016), U.S. EPA,

Office of Mobile Sources, Fuels and

Energy Division, Mail Code 6406J, 401

M Street SW, Washington, DC 20460.

SUPPLEMENTARY INFORMATION: Electronic

copies of this rule and earlier

rulemaking documents related to the F/

FA Registration Program are available

free of charge on EPA’s Technology

Transfer Network Bulletin Board System

(TTNBBS, phone access 919–541–5742)

and on the Internet (http://

www.epa.gov/omswww). Parties

requiring assistance may call Mr.

Fernandes at (202) 233–9016.

I. Regulated Entities

Regulated categories and entities

potentially affected by this action

include:

Category Examples of regulated entities

Industry Manufacturers of gasoline and diesel fuel.

Manufacturers of additives for gasoline and diesel fuel.

This table is not intended to be

exhaustive, but rather provides a guide

for readers regarding entities likely to be

regulated by this action. This table lists

the types of entities that EPA is now

aware could potentially be regulated by

this action. Other types of entities not

listed in the table could also be

regulated. To determine whether your

entity is regulated by this action, you

should carefully examine this preamble

and the changes to the regulatory text.

You should also carefully examine all

provisions of the registration program at

40 CFR part 79.

II. Introduction

A. Background

The F/FA registration program is

authorized by section 211 of the Clean

Air Act (CAA) and codified in 40 CFR

part 79. In accordance with CAA

sections 211(a) and (b)(1), basic

registration requirements applicable to

gasoline and diesel fuels and their

additives were issued in 1975. These

regulations require manufacturers to

submit information on their F/FA

products, such as the commercial

identity, chemical composition,

purpose-in-use, and range of

concentration, in order to have such

products registered by the EPA.

Additional registration requirements,

implementing sections 211(b)(2) and (e),

were proposed in April 1992 and