200.13-1

Method 200.13

Determination of Trace Elements in Marine Waters by Off-Line

Chelation Preconcentration with Graphite Furnace Atomic Absorption

John T. Creed and Theodore D. Martin

Chemical Expsoure Research Branch

Human Exposure Research Division

Revision 1.0

September 1997

National Exposure Research Laboratory

Office of Research and Development

U.S. Environmental Protection Agency

Cincinnati, Ohio 45268
Revision 1.0 September 1997 200.13 - 2

Chemical Abstracts Service

Element Registry Numbers (CASRN)

Cadmium (Cd) 7440-43-9

Cobalt (Co) 7440-48-4

Copper (Cu) 7440-50-8

Lead (Pb) 7439-92-1

Nickel (Ni) 7440-02-0

Method 200.13

Determination of Trace Elements in Marine Waters by Off-Line Chelation

Preconcentration with Graphite Furnace Atomic Absorption

1.0 Scope and Application

1.1 This method describes procedures for preconcentration and determination of total recoverable trace

elements in marine waters, including estuarine water,

seawater and brines.

1.2 Acid solubilization is required prior to determination of total recoverable elements to facilitate breakdown

of complexes or colloids which might influence trace

element recoveries. This method should only be used for

preconcentration and determination of trace elements in

aqueous samples. 3.1 Calibration Blank (CB) -- A volume of reagent

1.3 This method is applicable to the following standards, but without the analytes, internal standards, or

elements: surrogate analytes.

1.4 Method detection limits (MDLs) for these reagent water or other blank matrix that is placed in a

elements will be dependent on the specific sample container in the laboratory and treated as a

instrumentation employed and the selected operating sample in all respects, including shipment to the sampling

conditions. MDLs in NASS-3 (Reference Material, site, exposure to sampling site conditions, storage,

National Research Council of Canada) were determined preservation, and all analytical procedures. The purpose

using the procedure described in Section 9.2.4 and are of the FRB is to determine if method analytes or other

listed in Table 1. interferences are present in the field environment.

1.5 A minimum of 6-months experience in graphite 3.4 Instrument Performance Check Solution (IPC)

furnace atomic absorption (GFAA) is recommended. -- A solution of one or more method analytes, surrogates,

2.0 Summary of Method

2.1 Nitric acid is dispensed into a beaker containing

an accurately weighed or measured, well-mixed,

homogeneous aqueous sample. The sample volume is

reduced to approximately 20 mL and then covered and

allowed to reflux. The resulting solution is diluted to

volume and is ready for analysis.

2.2 This method is used to preconcentrate trace elements using an iminodiacetate functionalized chelating

resin. Following acid solubilization, the sample is buff- 1,2

ered using an on-line system prior to entering the chelating column. Group I and II metals, as well as most

anions, are selectively separated from the analytes by

elution with ammonium acetate at pH 5.5. The analytes

are subsequently eluted into a simplified matrix consisting

of 0.75 M nitric acid and are determined by GFAA.

3.0 Definitions

water fortified with the same matrix as the calibration

3.2 Calibration Standard (CAL) -- A solution prepared from the primary dilution standard solution or stock

standard solutions and the internal standards and surrogate analytes. The CAL solutions are used to calibrate

the instrument response with respect to analyte concentration.

3.3 Field Reagent Blank (FRB) -- An aliquot of

internal standards, or other test substances used to

evaluate the performance of the instrument system with

respect to a defined set of criteria.

3.5 Laboratory Fortified Blank (LFB) -- An aliquot

of reagent water or other blank matrices to which known

quantities of the method analytes are added in the

laboratory. The LFB is analyzed exactly like a sample,

and its purpose is to determine whether the methodology
200.13 - 3 Revision 1.0 September 1997

is in control, and whether the laboratory is capable of trated solution containing one or more method analytes

making accurate and precise measurements. prepared in the laboratory using assayed reference ma3.6 Laboratory Fortified Sample Matrix (LFM) -- -

An aliquot of an environmental sample to which known 3.14 Total Recoverable Analyte (TRA) -- The conquantities of the method analytes are added in the centration of analyte determined to be in either a solid

laboratory. The LFM is analyzed exactly like a sample, sample or an unfiltered aqueous sample following treatand its purpose is to determine whether the sample matrix ment by refluxing with hot dilute mineral acid(s) as

contributes bias to the analytical results. The background specified in the method.

concentrations of the analytes in the sample matrix must

be determined in a separate aliquot and the measured

values in the LFM corrected for background

concentrations.

3.7 Laboratory Reagent Blank (LRB) -- An aliquot

of reagent water or other blank matrices that are treated

exactly as a sample including exposure to all glassware,

equipment, solvents, reagents, internal standards, and

surrogates that are used with other samples. The LRB is

used to determine if method analytes or other

interferences are present in the laboratory environment,

the reagents, or the apparatus.

3.8 Linear Dynamic Range (LDR) -- The absolute

quantity or concentration range over which the instrument

response to an analyte is linear.

3.9 Matrix Modifier (MM) -- A substance added to

the instrument along with the sample in order to minimize

the interference effects by selective volatilization of either

analyte or matrix components.

3.10 Method Detection Limit (MDL) -- The minimum

concentration of an analyte that can be identified, measured and reported with 99% confidence that the analyte

concentration is greater than zero.

3.11 Quality Control Sample -- A solution of method

analytes of known concentrations which is used to fortify

an aliquot of LRB or sample matrix. The QCS is obtained

from a source external to the laboratory and different

from the source of calibration standards. It is used to

check laboratory performance with externally prepared

test materials.

3.12 Standard Addition -- The addition of a known

amount of analyte to the sample in order to determine the

relative response of the detector to an analyte within the

sample matrix. The relative response is then used to

assess either an operative matrix effect or the sample

analyte concentration.

3.13 Stock Standard Solution (SSS) -- A concenterials or purchased from a reputable commercial source.

4.0 Interferences

4.1 Several interference sources may cause

inaccuracies in the determination of trace elements by

GFAA. These interferences can be classified into three

major subdivisions: spectral, matrix, and memory. Some

of these interferences can be minimized via the preconcentration step, which reduces the Ca, Mg, Na and Cl

concentration in the sample prior to GFAA analysis.

4.2 Spectral interferences are caused by absorbance

of light by a molecule or atom which is not the analyte of

interest or emission from black body radiation.

4.2.1 Spectral interferences caused by an element only

occur if there is a spectral overlap between the wavelength of the interfering element and the analyte of

interest. Fortunately, this type of interference is relatively

uncommon in STPGFAA (Stabilized Temperature Platform Graphite Furnace Atomic Absorption) because of

the narrow atomic line widths associated with STPGFAA.

In addition, the use of appropriate furnace temperature

programs and high spectral purity lamps as light sources

can minimize the possibility of this type of interference.

However, molecular absorbances can span several hundred manometers, producing broadband spectral interferences. This type of interference is far more common

in STPGFAA. The use of matrix modifiers, selective

volatilization, and background correctors are all attempts

to eliminate unwanted nonspecific absorbance. Because

the nonspecific component of the total absorbance can

vary considerably from sample type to sample type, to

provide effective background correction and eliminate the

elemental spectral interference of palladium on copper

and iron on selenium, the exclusive use of Zeeman

background correction is specified in this method.

4.2.2 Spectral interferences are also caused by emissions from black body radiation produced during the

atomization furnace cycle. This black body emission 
Revision 1.0 September 1997 200.13 - 4

reaches the photomultiplier tube, producing erroneous

results. The magnitude of this interference can be minimized by proper furnace tube alignment and monochromator design. In addition, atomization temperatures

which adequately volatilize the analyte of interest without

producing unnecessary black body radiation can help reduce unwanted background emission produced during

atomization.

4.3 Matrix interferences are caused by sample cornponents which inhibit formation of free atomic analyte

atoms during the atomization cycle. In this method the

use of a delayed atomization device which provides

warmer gas phase temperatures is required. These

devices provide an environment which is more conducive

to the formation of free analyte atoms and thereby

minimize this type of interference. This type of interference can be detected by analyzing the sample plus a

sample aliquot fortified with a known concentration of the

analyte. If the determined concentration of the analyte

addition is outside a designated range, a possible matrix

effect should be suspected (Section 9.4).

4.4 Memory interferences result from analyzing a

sample containing a high concentration of an element

(typically a high atomization temperature element) which

cannot be removed quantitatively in one complete set of

furnace steps. The analyte which remains in the furnace

can produce false positive signals on subsequent

sample(s). Therefore, the analyst should establish the

analyte concentration which can be injected into the

furnace and adequately removed in one complete set of

furnace cycles. If this concentration is exceeded, the

sample should be diluted and a blank analyzed to assure

the memory effect has been eliminated before reanalyzing the diluted sample.

4.5 Low recoveries may be encountered in the

preconcentration cycle if the trace elements are

complexed by competing chelators (humic/fulvic) in the

sample or are present as colloidal material. Acid solubilization pretreatment is employed to improve analyte

recovery and to minimize adsorption, hydrolysis and

precipitation effects.

4.6 Memory interferences from the chelating system

may be encountered, especially after analyzing a sample

containing high analyte concentrations. A thorough column rinsing sequence following elution of the analytes is

necessary to minimize such interferences.

5.0 Safety

5.1 The toxicity or carcinogenicity of each reagent

used in this method has not been fully established. Each

chemical should be regarded as a potential health hazard

and exposure to these compounds should be as low as

reasonably achievable. Each laboratory is responsible for

maintaining a current awareness file of OSHA regulations

regarding the safe handling of the chemicals specified in

this method. A reference file of material data handling 3-6

sheets should also be made available to all personnel

involved in the chemical analysis. Specifically,

concentrated nitric and hydrochloric acids present various

hazards and are moderately toxic and extremely irritating

to skin and mucus membranes. Use these reagents in a

fume hood whenever possible and if eye or skin contact

occurs, flush with large volumes of water. Always wear

safety glasses or a shield for eye protection, protective

clothing and observe proper mixing when working with

these reagents.

5.2 Acidification of samples containing reactive materials may result in release of toxic gases, such as cyanides or sulfides. Samples should be acidified in a fume

hood.

5.3 All personnel handling environmental samples

known to contain or to have been in contact with human

waste should be immunized against known disease

causative agents.

5.4 The graphite tube during atomization emits intense UV radiation. Suitable precautions should be taken

to protect personnel from such a hazard.

5.5 The use of the argon/hydrogen gas mixture

during the dry and char steps may evolve a considerable

amount of HCI gas. Therefore, adequate ventilation is

required.

5.6 It is the responsibility of the user of this method to

comply with relevant disposal and waste regulations. For

guidance see Sections 14.0 and 15.0.

6.0 Equipment and Supplies

6.1 Graphite Furnace Atomic Absorption 

Spectrometer

6.1.1 The GFAA spectrometer must be capable of

programmed heating of the graphite tube and the
200.13 - 5 Revision 1.0 September 1997

associated delayed atomization device. The instrument 6.2.5 Eluent pumping system (Gradient Pump) -- Proshould be equipped with an adequate background

correction device capable of removing undesirable nonspecific absorbance over the spectral region of interest.

The capability to record relatively fast (< 1 sec) transient

signals and evaluate data on a peak area basis is 6.2.6 System setup, including sample loop (See

preferred. In addition, a recirculating refrigeration unit is Figure 1).

recommended for improved reproducibility of furnace

temperatures. The data shown in the tables were

obtained using the stabilized temperature platform and

Zeeman background correction.

6.1.2 Single element hollow cathode lamps or single

element electrodeless discharge lamps along with the pump (Dionex QIC pump or equivalent) for delivering 2M

associated power supplies. ammonium acetate buffer solution; carrier pump, peri6.1.3 Argon gas supply (high-purity grade, 99.99%). 1% nitric acid carrier solution; sample pump, peristaltic

6.1.4 A 5% hydrogen in argon gas mix and the

necessary hardware to use this gas mixture during

specific furnace cycles.

6.1.5 Autosampler-- Although not specifically required,

the use of an autosampler is highly recommended.

6.1.6 Graphite Furnace 0perating Conditions -- A

guide to experimental conditions for the applicable

elements is provided in Table 1.

6.2 Preconcentration System -- System containing

no metal parts in the analyte flow path, configured as

shown with a sample loop in Figure 1 and without a

sample loop in Figure 2.

6.2.1 Column -- Macroporous iminodiacetate chelating

resin (Dionex Metpac CC-1 or equivalent).

6.2.2 Control valves -- Inert double stack, pneumatically operated four-way slider valves with connectors.

6.2.2.1 Argon gas supply regulated at 80-100 psi.

6.2.3 Solution reservoirs -- Inert containers, e.g., high

density polyethylene (HDPE), for holding eluent and

carrier reagents.

6.2.4 Tubing -- High pressure, narrow bore, inert tubing

such as Tefzel ETFE (ethylene tetra-fluoro ethylene) or

equivalent for interconnection of pumps/ valve assemblies

and a minimum length for connection of the preconcentration system with the sample collection vessel.

grammable flow, high-pressure pumping system, capable

of delivering either one of three eluents at a pressure up

to 2000 psi and a flow rate of 1-5 mL/min.

6.2.6.1 Sample loop -- 10-mL loop constructed from

narrow bore, high-pressure inert tubing, Tefzel ETFE or

equivalent.

6.2.6.2 Auxiliary pumps -- On-line buffer pump, piston

staltic pump (Gilson Minipuls or equivalent) for delivering

pump for loading sample loop.

6.2.7 System setup without sample loop (See

Figure 2).

6.2.7.1 Auxiliary Pumps - Sample pump (Dionex QIC

Pump or equivalent) for loading sample on the column.

Carrier pump (Dionex QIC Pump or equivalent) used to

flush collection line between samples.

6.3 Labware -- For determination of trace elements,

contamination and loss are of critical consideration.

Potential contamination sources include improperly

cleaned laboratory apparatus and general contamination

within the laboratory environment. A clean laboratory

work area, designated for trace element sample handling

must be used. Sample containers can introduce positive

and negative errors in determination of trace elements by

(1) contributing contaminants through surface desorption

or leaching and (2) depleting element concentrations

through adsorption processes. For these reasons, borosilicate glass is not recommended for use with this

method. All labware in contact with the sample should be

cleaned prior to use. Labware may be soaked overnight

and thoroughly washed with laboratory-grade detergent

and water, rinsed with water, and soaked for 4 h in a

mixture of dilute nitric and hydrochloric acids, followed by

rinsing with ASTM type I water and oven drying.

6.3.1 Griffin beakers, 250 mL, polytetrafluoroethylene

(PTFE) or quartz.

6.3.2 Storage bottles -- Narrow mouth bottles, Teflon

FEP (fluorinated ethylene propylene), or HDPE, 125-mL

and 250-mL capacities.
Revision 1.0 September 1997 200.13 - 6

6.4 Sample Processing Equipment Note: It is recommended that the matrix modifier be

6.4.1 Air displacement pipetter -- Digital pipet system the modifier to the overall laboratory blank.

capable of delivering volumes from 100 to 2500 μL with

an assortment of metal-free, disposable pipet tips.

6.4.2 Balances -- Analytical balance, capable of

accurately weighing to ± 0.1 mg; top pan balance,

accurate to ± 0.01 g. nium hydroxide is recommended.

6.4.3 Hot plate -- Corning PC100 or equivalent. 7.1.5 Ammonium acetate buffer 1M, pH 5.5 -- Add 58

6.4.4 Centrifuge -- Steel cabinet with guard bowl,

electric timer and brake.

6.4.5 Drying oven -- Gravity convection oven with thermostatic control capable of maintaining 105EC ± 5EC.

6.4.6 pH meter -- Bench mounted or hand-held electrode system with a resolution of ± 0.1 pH units.

6.4.7 Class 100 hoods are recommended for all

sample handling.

7.0 Reagents and Standards

7.1 Reagents may contain elemental impurities which

might affect analytical data. Only high-purity reagents

that conform to the American Chemical Society specifications should be used whenever possible. If the purity 7

of a reagent is in question, analyze for contamination. All

acids used for this method must be of ultra high-purity

grade or equivalent. Suitable acids are available from a

number of manufacturers. Redistilled acids prepared by

sub-boiling distillation are acceptable.

7.1.1 Nitric acid, concentrated (sp.gr. 1.41).

7.1.1.1 Nitric acid 0.75M -- Dilute 47.7 mL (67.3g) conc.

nitric acid to 1000 mL with ASTM type I water.

7.1.1.2 Nitric acid (1+1) -- Dilute 500 mL conc. nitric acid

to 1000 mL with ASTM type I water.

7.1.1.3 Nitric acid (1+9) -- Dilute 100 mL conc. nitric acid

to 1000 mL with ASTM type I water.

7.1.2 Matrix Modifier, dissolve 300 mg Palladium (Pd)

powder in a minimum amount of concentrated HN03 (1

mL of HNO , adding concentrated HCl only if necessary). 3

Dissolve 200 mg of Mg(NO ) C6H O in ASTM type I water. 3 2 2

Pour the two solutions together and dilute to 100 mL with

ASTM type I water.

analyzed separately in order to assess the contribution of

7.1.3 Acetic acid, glacial (sp.gr. 1.05). High purity acetic

acid is recommended.

7.1.4 Ammonium hydroxide (20%). High purity ammomL (60.5 g) of glacial acetic acid to 600 mL of ASTM type

I water. Add 65 mL (60 g) of 20% ammonium hydroxide

and mix. Check the pH of the resulting solution by

withdrawing a small aliquot and testing with a calibrated

pH meter, adjusting the solution to pH 5.5 ± 0.1 with small

volumes of acetic acid or ammonium hydroxide as necessary. Cool and dilute to 1 L with ASTM type I water.

7.1.6 Ammonium acetate buffer 2M, pH 5.5 -- Prepare

as for Section 7.1.5 using 116 mL (121 g) glacial acetic

acid and 130 mL (120 g) 20% ammonium hydroxide,

diluted to 1000 mL with ASTM type I water.

Note: If the system is configured as shown in Figure 1,

the ammonium acetate buffer solutions may be further

purified by passing them through the chelating column at

a flow rate of 5.0 mL/min. Collect the purified solution in

a container. Following this, elute the collected contaminants from the column using 0.75M nitric acid for 5 min at

a flow rate of 4.0 mL/min. If the system is configured as

shown in Figure 2, the majority of the buffer is being

purified in an on-line configuration via the clean-up column.

7.1.7 Oxalic acid dihydrate (CASRN 6153-56-6),

0.2M -- Dissolve 25.2 g reagent grade C2H2O4C2H2O in

250 mL ASTM type I water and dilute to 1000 mL with

ASTM type I water. CAUTION - Oxalic acid is toxic;

handle with care.

7.2 Water -- For all sample preparation and dilutions,

ASTM type I water (ASTM D1193) is required.

7.3 Standard Stock Solutions -- May be purchased

from a reputable commercial source or prepared from

ultra high-purity grade chemicals or metals (99.99 -

99.999% pure). All salts should be dried for one hour at

105EC, unless otherwise specified. (CAUTION - Many

metal salts are extremely toxic if inhaled or swallowed.

Wash hands thoroughly after handling.) Stock solutions

should be stored in plastic bottles. The following procedures may be used for preparing standard stock solutions:
200.13 - 7 Revision 1.0 September 1997

Note: Some metals, particularly those which form sur- dards should be sufficiently high to produce good meaface oxides require cleaning prior to being weighed. This surement precision and to accurately define the slope of

may be achieved by pickling the surface of the metal in the response curve.

acid. An amount in excess of the desired weight should

be pickled repeatedly, rinsed with water, dried and 7.5 Blanks -- Four types of blanks are required for

weighed until the desired weight is achieved. this method. A calibration blank is used to establish the

7.3.1 Cadmium solution, stock 1 mL = 1000 μg Cd -- (LRB) is used to assess possible contamination from the

Pickle cadmium metal in (1+9) nitric acid to an exact

weight of 0.100 g. Dissolve in 5 mL (1+1) nitric acid,

heating to effect solution. Cool and dilute to 100 mL with

ASTM type I water.

7.3.2 Cobalt solution, stock 1 mL = 1000 μg Co -- acids (Section 7.1) and ASTM type I water.

Pickle cobalt metal in (1+9) nitric acid to an exact weight

of 0.100 g. Dissolve in 5 mL (1+1) nitric acid, heating to

effect solution. Cool and dilute to 100 mL with ASTM type acid diluent in ASTM type I water. The calibration blank

I water. should be stored in a FEP bottle.

7.3.3 Copper solution, stock 1 mL = 1000 μg Cu --

Pickle copper metal in (1+9) nitric acid to an exact weight

of 0.100 g. Dissolve in 5 mL (1+1) nitric acid, heating to

effect solution. Cool and dilute to 100 mL with ASTM type

I water.

7.3.4 Lead solution, stock 1 mL = 1000 μg Pb --

Dissolve 0.1599 g PbNO3 in 5 mL (1+1) nitric acid. Dilute

to 100 mL with ASTM type I water.

7.3.5 Nickel solution, stock 1 mL = 1000 μg Ni --

Dissolve 0.100 g nickel powder in 5 mL conc. nitric acid,

heating to effect solution. Cool and dilute to 100 mL with

ASTM type I water.

7.4 Multielement Stock Standard Solution -- Care

must be taken in the preparation of multielement stock

standards that the elements are compatible and stable.

Originating element stocks should be checked for the

presence of impurities which might influence the accuracy

of the standard. Freshly prepared standards should be

transferred to acid cleaned, new FEP or HDPE bottles for

storage and monitored periodically for stability. A

multielement stock standard solution containing cadmium, cobalt, copper, lead, and nickel may be prepared

by diluting an appropriate aliquot of each single element

stock in the list to 100 mL with ASTM type I water

containing 1% (v/v) nitric acid.

7.4.1 Preparation of calibration standards -- Fresh

multielement calibration standards should be prepared

weekly. Dilute the stock multielement standard solution

in 1% (v/v) nitric acid to levels appropriate to the required

operating range. The element concentrations in the stananalytical calibration curve, the laboratory reagent blank

sample preparation procedure and to assess spectral

background. The laboratory fortified blank is used to

assess routine laboratory performance, and a rinse blank

is used to flush the instrument autosampler uptake system. All diluent acids should be made from concentrated

7.5.1 The calibration blank consists of the appropriate

7.5.2 The laboratory reagent blanks must contain all

the reagents in the same volumes as used in processing

the samples. The preparation blank must be carried

through the entire sample digestion and preparation

scheme.

7.5.3 The laboratory fortified blank (LFB) is prepared

by fortifying an aliquot of the laboratory reagent blank with

all analytes to provide a final concentration which will

produce an absorbance of approximately 0.1 for each

analyte. The LFB must be carried through the complete

procedure as used for the samples.

7.5.4 The rinse blank is prepared as needed by adding

1.0 mL of conc. HNO and 1.0 mL conc. HCI to 1 L of 3

ASTM Type I water and stored in a convenient manner.

7.6 Instrument Performance Check (IPC) Solution

-- The IPC solution is used to periodically verify instrument

performance during analysis. The IPC solution should be

a fortified seawater prepared in the same acid mixture as

the calibration standards and should contain method

analytes such that the resulting absorbances are near the

midpoint of the calibration curve. The IPC solution should

be prepared from the same standard stock solutions used

to prepare the calibration standards and stored in a FEP

bottle. Agency programs may specify or request that

additional instrument performance check solutions be

prepared at specified concentrations in order to meet

particular program needs.

7.7 Quality Control Sample (QCS) -- A quality control sample having certified concentrations of the analytes

of interest should be obtained from a source outside the
Revision 1.0 September 1997 200.13 - 8

laboratory. Dilute the QCS if necessary with 1% nitric 9.2 Initial Demonstration of Performance 

acid, such that the analyte concentrations fall within the (Mandatory)

proposed instrument calibration range.

8.0 Sample Collection, Preservation and

Storage

8.1 Prior to collection of an aqueous sample,

consideration should be given to the type of data required,

so that appropriate preservation and pretreatment steps

can be taken. Acid preservation, etc., should be

performed at the time of sample collection or as soon

thereafter as practically possible. The pH of all aqueous

samples must be tested immediately prior to aliquoting for

analysis to ensure the sample has been properly

preserved. If properly acid-preserved, the sample can be

held up to 6 months before analysis.

8.2 For determination of total recoverable elements

in aqueous samples, acidify with (1+1) nitric acid at the

time of collection to pH < 2. Normally 3 mL of (1+1) acid

per liter of sample is sufficient. The sample should not be

filtered prior to analysis.

Note: Samples that cannot be acid-preserved at the

time of collection because of sampling limitations or

transport restrictions, or have pH > 2 because of high

alkalinity should be acidified with nitric acid to pH < 2 upon

receipt in the laboratory. Following acidification, the

sample should be held for 16 h and the pH verified to be

<2 before withdrawing an aliquot for sample processing.

8.3 For aqueous samples, a field blank should be

prepared and analyzed as required by the data user. Use

the same container type and acid as used in sample

collection.

9.0 Quality Control

9.1 Each laboratory using this method is required to

operate a formal quality control (QC) program. The

minimum requirements of this program consist of an initial

demonstration of laboratory capability and periodic

analysis of laboratory reagent blanks, fortified blanks and

other laboratory solutions as a continuing check on

performance. The laboratory is required to maintain

performance records that define the quality of the data

generated.

9.2.1 The initial demonstration of performance is used to

characterize instrument performance (determination of

linear dynamic ranges and analysis of quality control

samples) and laboratory performance (determination of

method detection limits) prior to samples being analyzed

by this method.

9.2.2 Linear dynamic range (LDR) -- The upper limit of

the LDR. must be established for the wavelength utilized

for each analyte by determining the signal responses

from a minimum of 6 different concentration standards

across the range, two of which are close to the upper limit

of the LDR. Determined LDRs must be documented and

kept on file. The linear calibration range which may be

used for analysis of samples should be judged by the

analyst from the resulting data. The upper LDR. limit

should be an observed signal no more than 10% below

the level extrapolated from the four lower standards. New

LDRs should be determined whenever there is a

significant change in instrument response, a change in

instrument analytical hardware or operating conditions.

Note: Multiple cleanout furnace cycles may be necessary

in order to fully define or utilize the LDR. for certain

elements such as nickel. For this reason, the upper limit

of the linear calibration range may not correspond to the

upper LDR limit.

Measured sample analyte concentrations that exceed the

upper limit of the linear calibration range must either be

diluted and reanalyzed with concern for memory effects

(Section 4.4) or analyzed by another approved method.

9.2.3 Quality control sample (QCS) -- When beginning

the use of this method, on a quarterly basis or as required

to meet data-quality needs, verify the calibration standards and acceptable instrument performance with the

preparation and analyses of a QCS (Section 7.7). If the

determined concentrations are not within ± 10% of the

stated values, performance of the determinative step of

the method is unacceptable. The source of the problem

must be identified and corrected before either proceeding

on with the initial determination of method detection limits

or continuing with ongoing analyses.

9.2.4 Method detection limit (MDL) -- MDLs must be

established for all analytes, using reagent water (blank)

fortified at a concentration of two to three times the

estimated instrument detection limit. To determine MDL 8

values, take seven replicate aliquots of the fortified
200.13 - 9 Revision 1.0 September 1997

reagent water and process through the entire analytical problem should be identified and resolved before

method. Perform all calculations defined in the method continuing analyses.

and report the concentration values in the appropriate

units. Calculate the MDL as follows: 9.3.3 The laboratory must use LFB analyses data to

MDL = (t) x (S)

where, t = Student's t value for a 99% confidence level

and a standard deviation estimate with n-1

degrees of freedom [t = 3.14 for seven

replicates].

 S= standard deviation of the replicate

analyses.

Note: If the relative standard deviation (RSD) from the

analyses of the seven aliquots is < 15%, the concentration

used to determine the analyte MDL may have been in

appropriately high for the determination. lf so, this could

result in the calculation of an unrealistically low MDL. If

additional confirmation of the MDL is desired, reanalyze

the seven replicate aliquots on two more nonconsecutive

days and again calculate the MDL values for each day.

An average of the three MDL values for each analyte may

provide for a more appropriate MDL estimate. Determination of MDL in reagent water represents a best case

situation and does not reflect possible matrix effects of

real world samples. However, successful analyses of 9.3.4 Instrument Performance Check (IPC) Solution --

LFMs (Section 9.4) can give confidence to the MDL value

determined in reagent water. Typical single laboratory

MDL values using this method are given in Table 1. MDLs

should be determined every 6 months, when a new

operator begins work, or whenever there is a significant

change in the background or instrument response.

9.3 Assessing Laboratory Performance 

(Mandatory)

9.3.1 Laboratory reagent blank (LRB) - The laboratory

must analyze at least one LRB (Section 7.5.2) with each the second analysis of the IPC solution confirms

batch of 20 or fewer samples. LRB data are used to calibration to be outside the limits, sample analysis must

assess contamination from the laboratory environment. be discontinued, the cause determined and/or in the case

LRB values that exceed the MDL indicate laboratory or of drift the instrument recalibrated. All samples following

reagent contamination should be suspected. Any deter- the last acceptable IPC solution must be reanalyzed. The

mined source of contamination must be corrected and the analysis data of the calibration blank and IPC solution

samples reanalyzed for the affected analytes after must be kept on file with the sample analyses data.

acceptable LRB values have been obtained.

9.3.2 Laboratory fortified blank (LFB) -- The laboratory

must analyze at least one LFB (Section 7.5.3) with each control the method blank. Therefore, it is recommended

batch of samples. Calculate accuracy as percent recov- that the calibration blank response be recorded for each

ery (Section 9.4.3). If the recovery of any analyte falls set of samples. This record will aid the laboratory in

outside the required control limits of 85-115%, that assessing both its long- and short-term ability to control

analyte is judged out of control, and the source of the the method blank.

assess laboratory performance against the required control limits of 85-115% (Section 9.3.2). When sufficient

internal performance data become available (usually a

minimum of 20-30 analyses), optional control limits can

be developed from the percent mean recovery (x) and the

standard deviation (S) of the mean recovery. These data

can be used to establish the upper and lower control

limits as follows:

Upper Control Limit = x + 3S

Lower Control Limit = x - 3S

The optional control limits must be equal to or better than

the required control limits of 85-115%. After each 5-10

new recovery measurements, new control limits can be

calculated using only the most recent 20-30 data points.

Also, the standard deviation (S) data should be used to

establish an ongoing precision statement for the level of

concentrations included in the LFB. These data must be

kept on file and be available for review.

For all determinations the laboratory must analyze the

IPC solution (Section 7.6) and a calibration blank immediately following each calibration, after every tenth sample

(or more frequently, if required) and at the end of the

sample run. The IPC solution should be a fortified

seawater matrix. Analysis of the IPC solution and

calibration blank immediately following calibration must

verify that the instrument is within ±10% of calibration.

Subsequent analyses of the IPC solution must be within

±10% of calibration. If the calibration cannot be verified

within the specified limits, reanalyze the IPC solution. If

9.3.5 The overall sensitivity and precision of this

method are strongly influenced by a laboratory’s ability to
Revision 1.0 September 1997 200.13 - 10

9.4 Assessing Analyte Recovery and Data influences the column's ability to preconcentrate the

Quality metals; therefore, a low recovery may be caused by a low

9.4.1 Sample homogeneity and the chemical nature of analyst is advised to make an in furnace analyte addition

the sample matrix can affect analyte recovery and data

quality. Taking separate aliquots from the sample for

replicate and fortified analyses can, in some cases,

assess these effects. Unless otherwise specified by the

data user, laboratory or program, the following laboratory

fortified matrix (LFM) procedure (Section 9.4.2) is

required.

9.4.2 The laboratory must add a known amount of as NASS-3 (from the Research Council of Canada) be

each analyte to a minimum of 10% of routine samples.

In each case, the LFM aliquot must be a duplicate of the

aliquot used for sample analysis and for total recoverable

determinations added prior to sample preparation. For

water samples, the added analyte concentration must be

the same as that used in the laboratory fortified blank

(Section 7.5.3). Over time, samples from all routine

sample sources should be fortified.

9.4.3 Calculate the percent recovery for each analyte,

corrected for concentrations measured in the unfortified

sample, and compare these values to the designated

LFM recovery range of 75-125%. Recovery calculations

are not required if the concentration added is <25% of the

unfortified sample concentration. Percent recovery may

be calculated in units appropriate to the matrix, using the

following equation:

R = Cs - C x 100

s

where, R = percent recovery.

C = fortified sample concentration. s

C = sample background concentration.

s = concentration equivalent of analyte 

added to sample.

9.4.4 If the recovery of any analyte falls outside the

designated LFM recovery range (but is still within the

range of calibration and the background absorbance is <

1 abs.) and the laboratory performance for that analyte is

shown to be in control (Section 9.3), the recovery problem

encountered with the LFM is judged to be either matrix or

solution related, not system related. This situation should

be rare given the matrix elimination preconcentration step

prior to analysis. If a low recovery is found, check the pH

of the sample plus the buffer mixture. The resulting pH

should be about 5.5. The pH of the sample strongly

pH. If the pH for the LFM/buffer mixture is about 5.5, the

to the LFM using the preconcentrated standard solution.

If recovery of the in furnace analyte addition is shown to

be out of control, a matrix interference is confirmed and

the sample must be analyzed by MSA.

9.5 Utilizing Reference Materials

9.5.1 It is recommended that a reference material such

fortified and used as an Instrument Performance Check

Solution.

10.0 Calibration and Standardization

10.1 The preconcentration system can be configured

utilizing a sample loop to define the sample volume

(Figure 1) or the system can be configured such that a

sample pump rate and a pumping time defines the

sample volume (Figure 2). The system illustrated in

Figure 1 is recommended for sample sizes of <10 mL. A

thorough rinsing of the sample loop between samples

with HNO3 is required. This rinsing will minimize the

cross-contamination which may be caused by the sample

loop. The system in Figure 2 should be used for sample

volumes of >10 mL. The sample pump used in Figure 2

must be calibrated to assure that a reproducible/defined

volume is being delivered.

10.2 Specific wavelengths and instrument operating

conditions are listed in Table 1. However, because of

differences among makes and models of spectrophotometers and electrothermal furnace devices, the actual

instrument conditions selected may vary from those listed.

10.3 Prior to the use of this method, instrument operating conditions must be optimized. The analyst should

follow the instructions provided by the manufacturer while

using the conditions listed in Table 1 as a guide. Of

particular importance is the determination of the charring

temperature limit for each analyte. This limit is the furnace temperature setting where a loss in analyte will

occur prior to atomization. This limit should be determined by conducting char temperature profiles for each

analyte and when necessary, in the matrix of question.

The charring temperature selected should minimize background absorbance while providing some furnace temperature variation without loss of analyte. For routine

analytical operation the charring temperature is usually
200.13 - 11 Revision 1.0 September 1997

set at least 100EC below this limit. The optimum condi- 11.1.3 Cover the lip of the beaker with a watch glass to

tions selected should provide the lowest reliable MDLs

and be similar to those listed in Table 1. Once the

optimum operating conditions are determined, they

should be recorded and available for daily reference.

10.4 Prior to an initial calibration, the linear dynamic

range of the analyte must be determined (Section 9.2.2)

using the optimized instrument operating conditions. For

all determinations allow an instrument and hollow cathode lamp warm-up period of not less than 15 min. If an

EDL is to be used, allow 30 min for warm-up.

10.5 Before using the procedure (Section 11.0) to analyze samples, data must be available to document initial

demonstration of performance. The required data and

procedure are described in Section 9.2. This data must be

generated using the same instrument operating

conditions and calibration routine (Section 11.4) to be

used for sample analysis. These documented data must

be kept on file and be available for review by the data

user.

11.0 Procedure

11.1 Sample Preparation -- Total Recoverable

Elements

11.1.1 Add 2 mL (1+1) nitric acid to the beaker

containing 100 mL of sample. Place the beaker on the

hot plate for solution evaporation. The hot plate should

be located in a fume hood and previously adjusted to

provide evaporation at a temperature of approximately but

no higher than 85EC. (See the following note.) The

beaker should be covered with an elevated (ribbed) watch

glass or other necessary steps should be taken to prevent

sample contamination from the fume hood environment.

Note: For proper heating adjust the temperature control

of the hot plate such that an uncovered Griffin beaker

containing 50 mL of water placed in the center of the hot

plate can be maintained at a temperature approximately

but no higher than 85EC. (Once the beaker is covered

with a watch glass the temperature of the water will rise

to approximately 95EC.)

11.1.2 Reduce the volume of the sample aliquot to

about 20 mL by gentle heating at 85EC. DO NOT BOIL.

This step takes about 2 hr for a 100-mL aliquot with the

rate of evaporation rapidly increasing as the sample

volume approaches 20 mL. (A spare beaker containing

20 mL of water can be used as a gauge.)

reduce additional evaporation and gently reflux the

sample for 30 min. Slight boiling may occur, but vigorous

boiling must be avoided.

11.1.4 Allow the beaker to cool. Quantitatively transfer

the sample solution to a 100-mL volumetric flask, dilute

to volume with reagent water, stopper and mix.

11.1.5 Allow any undissolved material to settle overnight, or centrifuge a portion of the prepared sample until

clear. (If after centrifuging or standing overnight the

sample contains suspended solids that would clog or

affect the sample introduction system, a portion of the

sample may be filtered prior to analysis. However, care

should be exercised to avoid potential contamination from

filtration.) The sample is now ready for analysis. Because

the effects of various matrices on the stability of diluted

samples cannot be characterized, all analyses should be

performed as soon as possible after the completed

preparation.

11.2 Prior to first use, the preconcentration system

should be thoroughly cleaned and decontaminated using

0.2M - oxalic acid.

11.2.1 Precleaning the Preconcentration System

11.2.1.1 Place approximately 500 mL 0.2M - oxalic acid

in each of the sample/eluent containers. Flush the entire

system by running the program used for sample analysis

3 times.

11.2.1.2 Rinse the containers with ASTM type I water

and repeat the sequence described in Section 11.2.1.1

using 0.75M nitric acid and again using ASTM type I water

in place of the 0.2M - oxalic acid.

11.2.1.3 Rinse the containers thoroughly with ASTM type

I water, fill them with their designated reagents and run

through the program used for sample analysis in order to

prime the pump and all eluent lines with the correct

reagents.

11.2.2 Peak Profile Determination

11.2.2.1 The peak elution time or the collection window

should be determined using an ICP-AES (Inductively

Coupled Plasma Atomic Emission Spectrometer) or

Flame AA. Figure 3 is a plot of time vs. emission intensity

for Cd, Pb, Ni, and Cu. The collection window is marked

in Figure 3 and should provide about 30 sec buffer on
Revision 1.0 September 1997 200.13 - 12

either side of the peak. If an ICP-AES is not available, it 11.3.2.1 Sample Loading -- With the valves 1 and 2 on

is recommended that the peak profile be determined by and the sample pump on, load the sample on the column

collecting 200-μL samples during the elution part of the buffering the sample utilizing the gradient pump and the

preconcentration cycle and then reconstructing the peak 2M buffer. The actual sample volume is determined by

profile from the analysis of the 200-μL samples. knowing the sample pump rate and the time. While the

11.3 Sample Preconcentration flush the collection line.

11.3.1 Preconcentration utilizing a sample loop. 11.3.2.2 Elution Matrix -- With valve 1 in the off position

11.3.1.1 Loading Sample Loop -- With valve 1 in the off 1M ammonium acetate. During which time the carrier,

position and valve 2 in the on position, load sample buffer and the sample pumps are all off.

through the sample loop to waste using the sample pump

for 4 min at 4 mL/min. Switch on the carrier pump and 11.3.2.3 Elution of Analytes -- With valves l and 2 in the

pump 1 % nitric acid to flush the sample collection line. off position the gradient pump is switched to 0.75M HNO

11.3.1.2 Column Loading -- With valve 1 in the on The analytes should be eluted into a 2 mL sample

position, load sample from the loop onto the column volume.

using 1 M ammonium acetate for 4.5 min at 4.0 mL/min.

Switch on the buffer pump, and pump 2M ammonium 11.3.2.4 Column Reconditioning -- Turn on valve 2 to

acetate at a flow rate of 1 mL/min. The analytes are direct column effluent to waste, and pump 0.75M nitric

retained on the column, while the majority of the matrix is acid, 1M ammonium acetate, 0.75M nitric acid and 1M

passed through to waste. ammonium acetate alternately through the column at 4.0

11.3.1.3 Elution Matrix -- With valve 1 in the on position

the gradient pump is allowed to elute the matrix using the Note: When switching the gradient pump from nitric

1M ammonium acetate. During which time the carrier, acid back to the ammonium acetate it is necessary to

buffer and the sample pumps are all off. flush the line connecting the gradient pump to valve 2 with

11.3.1.4 Elute Analytes -- Turn off valve 1 and begin line contains nitric acid it will elute the metals from the

eluting the analytes by pumping 0.75M nitric acid through cleanup column.

the column and turn off valve 2 and pump the eluted

analytes into the collection flask. The analytes should be 11.3.2.5 Preconcentration of the sample may be aeluted into a 2-mL sample volume. chieved by running through an eluent pump program.

11.3.1.5 Column Reconditioning -- Turn on valve 2 to according to the internal volume of the connecting tubing

direct column effluent to waste, and pump 0.75M nitric and the specific hardware configuration used.

acid, 1M ammonium acetate, 0.75M nitric acid and 1M

ammonium acetate alternately through the column at 4.0 11.4 Repeat the sequence described in Section 11.3.1

mL/min. Each solvent should be pumped through the or 11.3.2 for each sample to be analyzed. At the end of

column for 2 min. During this process, the next sample the analytical run leave the column filled with 1M ammocan be loaded into the sample loop using the sample nium acetate buffer until it is next used.

pump.

11.3.1.6 Preconcentration of the sample may be a- established linear dynamic range should be diluted into

chieved by running through an eluent pump program. range and reanalyzed.

The exact timing of this sequence should be modified

according to the internal volume of the connecting tubing 11.6 Sample Analysis

and the specific hardware configuration used.

11.3.2 Preconcentration utilizing an auxiliary pump to

determine sample volume. sampler injector for any change that would affect

sample is being loaded the carrier pump can be used to

the gradient pump is allowed to elute the matrix using the

3

and the analytes are eluted into the collection vessel.

mL/min.

the ammonium acetate prior to switching the valve. If the

The exact timing of this sequence should be modified

11.5 Samples having concentrations higher than the

11.6.1 Prior to daily instrument calibration, inspect the

graphite furnace, the sample uptake system and autoinstrument performance. Clean the system and replace
200.13 - 13 Revision 1.0 September 1997

the graphite tube and/or platform when needed or on a 11.6.8 During sample analyses, the laboratory must

daily basis. A cotton swab dipped in a 50/50 mixture of

isopropyl alcohol (IPA) and H O (such that it is damp but 2

not dripping) can be used to remove the majority of the

salt buildup. A second cotton swab is dipped in IPA and

the contact rings are wiped down to assure they are

clean. The rings are then allowed to thoroughly dry and

then a new tube is placed in the furnace and conditioned

according to instrument manufacturers specifications.

11.6.2 Configure the instrument system to the selected

optimized operating conditions as determined in Sections

10.1 and 10.2.

11.6.3 Before beginning daily calibration the instrument

should be reconfigured to the optimized conditions. Ini- 11.6.10 Report data as directed in Section 12.

tiate data system and allow a period of not less than 15

min for instrument and hollow cathode lamp warm-up. If

an EDL is to be used, allow 30 min for warm-up.

11.6.4 After the warm-up period but before calibration,

instrument stability must be demonstrated by analyzing a

standard solution with a concentration 20 times the IDL a

minimum of five times. The resulting relative standard

deviation of absorbance signals must be <5%. If the

relative standard deviation is >5%, determine and correct

the cause before calibrating the instrument.

11.6.5 For initial and daily operation calibrate the instrument according to the instrument manufacturer’s recommended procedures using the calibration blank (Section

7.5.1) and calibration standards (Section 7.4) prepared at

three or more concentrations within the usable linear

dynamic range of the analyte (Sections 4.4 & 9.2.2).

11.6.6 An autosampler must be used to introduce all

solutions into the graphite furnace. Once the standard, corrected for nonanalyte signals. The unknown sample

sample or QC solution plus the matrix modifier is injected, concentration C is calculated:

the furnace controller completes furnace cycles and

cleanout period as programmed. Analyte signals must be C = S V C

integrated and collected as peak area measurements. (S -S )V

Background absorbances, background corrected analyte

signals, and determined analyte concentrations on all where, S and S are the analytical signals (corrected for

solutions must be able to be displayed on a CRT for the blank) of solutions A and B, respectively. V and C

immediate review by the analyst and be available as hard should be chosen so that S is roughly twice S on the

copy for documentation to be kept on file. Flush the average. It is best if V is made much less than V , and

autosampler solution uptake system with the rinse blank thus C is much greater than C , to avoid excess dilution

(Section 7.5.4) between each solution injected. of the sample matrix. If a separation or concentration

11.6.7 After completion of the initial requirements of this through the entire procedure. For the results from this

method (Section 9.2), samples should be analyzed in the

same operational manner used in the calibration routine.

comply with the required quality control described in

Sections 9.3 and 9.4.

11.6.9 Determined sample analyte concentrations that

are >90% of the upper limit of calibration must either be

diluted with acidified reagent water and reanalyzed with

concern for memory effects (Section 4.4), or determined

by another approved test procedure that is less sensitive.

Samples with a background absorbance > 1.0 must be

appropriately diluted with acidified reagent water and

reanalyzed (Section 9.4.6). If the method of standard

additions is required, follow the instructions described in

Section 11.5.

11.7 Standard Additions -- If the method of standard

addition is required, the following procedure is recommended:

11.7.1 The standard addition technique involves pre9

paring new standards in the sample matrix by adding

known amounts of standard to one or more aliquots of the

processed sample solution. This technique compensates

for a sample constituent that enhances or depresses the

analyte signal, thus producing a different slope from that

of the calibration standards. It will not correct for additive

interference, which causes a baseline shift. The simplest

version of this technique is the single addition method.

The procedure is as follows: Two identical aliquots of the

sample solution, each of volume Vx, are taken. To the

first (labeled A) is added a small volume VS of a standard

analyte solution of concentration Cs. To the second

(labeled B) is added the same volume V of the solvent. s

The analytical signals of A and B are measured and

x

X B S S

A B X

A B

S S

A B

S X

S X

step is used, the additions are best made first and carried

technique to be valid, the following limitations must be

taken into consideration:
Revision 1.0 September 1997 200.13 - 14

1. The analytical curve must be linear.

2. The chemical form of the analyte added must respond in the same manner as the analyte in the

sample.

3. The interference effect must be constant over the

working range of concern.

4. The signal must be corrected for any additive interference.

12.0 Data Analysis and Calculations

12.1 Sample data should be reported in units of μg/L

for aqueous samples. 14.2 For information about pollution prevention that

12.2 For total recoverable aqueous analytes (Section tions, consult Less is Better: Laboratory Chemical Man11.1), when 100-mL aliquot is used to produce the 100 agement for Waste Reduction, available from the AmerimL final solution, round the data to the tenths place and can Chemical Society’s Department of Government Rereport the data in μg/L up to three significant figures. If an lations and Science Policy, 1155 16th Street N.W., Washaliquot volume other than 100 mL is used for sample ington D.C. 20036, (202)872-4477.

preparation, adjust the dilution factor accordingly. Also,

account for any additional dilution of the prepared sample

solution needed to complete the determination of analytes exceeding the upper limit of the calibration curve.

Do not report data below the determined analyte MDL

concentration or below an adjusted detection limit

reflecting smaller sample aliquots used in processing or

additional dilutions required to complete the analysis.

12.3 The QC data obtained during the analyses

provide an indication of the quality of the sample data and

should be provided with the sample results.

13.0 Method Performance

13.1 Experimental conditions used for single available from the American Chemical Society at the

laboratory testing of the method are summarized in Table address listed in the Section 14.2.

1.

13.2 Table 2 contains precision and recovery data obtained from a single laboratory analysis of a fortified and

a non-fortified sample of NASS-3. The samples were

prepared using the procedure described in Section 11.1.

Four replicates of the non-fortified samples were

analyzed and the average of the replicates was used for

determining the sample analyte concentration. The fortified samples of NASS-3 were also analyzed and the

average percent recovery and the percent relative standard deviation is reported. The reference material certified values are also listed for comparison.

14.0 Pollution Prevention

14.1 Pollution prevention encompasses any technique

that reduces or eliminates the quantity or toxicity of waste

at the point of generation. Numerous opportunities for

pollution prevention exist in laboratory operation. The

EPA has established a preferred hierarchy of environmental management techniques that places pollution

prevention as the management option of first choice.

Whenever feasible, laboratory personnel should use

pollution prevention techniques to address their waste

generation (e.g., Section 7.8). When wastes cannot be

feasibly reduced at the source, the Agency recommends

recycling as the next best option.

may be applicable to laboratories and research institu15.0 Waste Management

15.1 The Environmental Protection Agency requires

that laboratory waste management practices be conducted consistent with all applicable rules and regulations. The Agency urges laboratories to protect the air,

water, and land by minimizing and controlling all releases

from hoods and bench operations, complying with the

letter and spirit of any sewer discharge permits and

regulations, and by complying with all solid and hazardous waste regulations, particularly the hazardous waste

identification rules and land disposal restrictions. For

further information on waste management consult The

Waste Management Manual for Laboratory Personnel,

16.0 References

1. A. Siraraks, H.M. Kingston and J.M. Riviello, Anal

Chem. 62 1185 (1990).

2. E.M. Heithmar, T.A. Hinners, J.T. Rowan and J.M.

Riviello, Anal Chem. 62 857 (1990).

3. OSHA Safety and Health Standards, General

Industry, (29 CFR 1910), Occupational Safety and

Health Administration, OSHA 2206, (Revised,

January 1976).
200.13 - 15 Revision 1.0 September 1997

4. Carcinogens - Working With Carcinogens, Department of Health, Education, and Welfare, Public

Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health,

Publication No. 77-206, Aug. 1977.

5. Proposed OSHA Safety and Health

Standards,Laboratories, Occupational Safety and

Health Administration, Federal Register, July 24,

1986.

6. Safety in Academic Chemistry Laboratories, American Chemical Society Publication, Committee on

Chemical Safety, 3rd Edition, 1979.

7. Rohrbough, W.G. et al. Reagent Chemicals,

American Chemical Society Specifications, 7th

edition. American Chemical Society, Washington,

DC, 1986.

8. Code of Federal Regulations 40, Ch. 1, Pt. 136

Appendix B.

9. Winefordner, J.D., Trace Analysis: Spectroscopic

Methods for Elements, Chemical Analysis, Vol. 46,

pp. 41-42,1976.
Revision 1.0 September 1997 200.13 - 16

17.0 Tables, Diagrams, Flowcharts, and Validation Data

Table 1. Method Detection Limits for Total Recoverable Analytes in Reagent Water1

Recommended

Slit, analytical Char Atomization MDL ,

2

Element nm Wavelengths, nm Temp, EC Temp, EC μg/L

Cadmium 0.7 228.8 800 1600 0.016

Cobalt 0.2 242.5 1400 2500 -

Copper 0.7 324.8 1300 2600 0.36

Lead 0.7 283.3 1250 2000 0.28

Nickel 0.2 232.4 1400 2500 *

 MDLs were calculated using NASS-3 as the matrix. 1

 MDLs were calculated based on a 10-mL sample loop. 2

* MDL was not calculated because the concentration in the matrix exceeds the MDL spike level.

- Not Determined.

Table 2. Precision and Recovery Data for NASS-3 Using System Illustrated in Figure 11,2

Certified Sample Fortified

Value, Conc., Conc., Avg.

Analyte μg/L μg/L μg/L Recovery, % % RSD 3 3

Cd 0.029 ± 0.004 0.026 ± 0.012 0.25 93 3.3

Co 0.004 ± 0.001 - - - -

Cu 0.109 ± 0.011 <0.36 5.0 87 1.4

Pb 0.039 ± 0.006 <0.28 5.0 90 3.7

Ni 0.257 ± 0.027 0.260 ± 0.04 5.0 117 8.3

 Data collected using 10-mL sample loop. 1

 Matrix modifier is Pd/Mg(NO ) /H .

2

3 2 2

 Uncertainties based on 95% confidence limits. 3

- Not determined.
200.13 - 17 Revision 1.0 September 1997

Valves Buffer Carrier Sample

1 2 Pump Pump Pump

Sample Loop 

Loading Off On Off On On

Column

Loading On On On Off Off

Elution of

Matrix On On Off Off Off

Elution of

Analytes Off Off Off Off Off

Column

Recondition Off On Off Off Off
Revision 1.0 September 1997 200.13 - 18

Valves Carrier Sample

Event 1 2 Pump Pump

Sample

Loading On On On On

Elution of

Matrix Off On Off Off

Elution of

Analytes Off Off Off Off

Column

Recondition Off On Off On
200.13 - 19 Revision 1.0 September 1997