SPECIAL REPORT 96-3

Sampling Trace-Level Organics

with Polymeric Tubings

Louise V. Parker and Thomas A. Ranney February 1996

(revised October 1996)
Abstract

There is concern whether tubings used to sample groundwater can affect contaminant concentrations. Tubings might sorb contaminants, thereby giving

falsely low values, or they might leach contaminants, thereby giving falsely

high values. There also is concern that a tubing used previously in a well with

high concentrations of contaminants might subsequently desorb contaminants into samples taken from other wells if decontamination is insufficient.

Our review of the literature indicated that these concerns are valid, although a

comprehensive study of this subject does not exist. In our laboratory study,

we looked for sorption of a suite of organic solutes by 20 polymeric tubings

under static conditions. Seven of these tubings were flexible and the others

were rigid. We found that among the rigid tubings tested, the three fluoropolymers (fluorinated ethylene propylene [FEP], FEP-lined polyethylene, and

polyvinylidene fluoride [PVDF]) were the least sorptive tubings. However,

even these tubings readily sorbed some of the analytes. Among the flexible

tubings tested, a fluoroelastomer tubing and a tubing made of a copolymer of

vinylidene fluoride and hexafluoropropylene (P[VDF-HFP]) were the least

sorptive. We also found that several of the 20 tubings appeared to leach

constituents into the test solution. We were unable to detect any evidence that

constituents leached from the polyethylene tubings, the rigid fluoropolymer

tubings, and one of the plasticized polypropylene tubings. Currently, we are

conducting studies to see whether the effects we observed in this study increase, decrease, or remain the same under dynamic conditions.

For conversion of SI units to non-SI units of measurement consult Standard

Practice for Use of the International System of Units (SI), ASTM Standard E380-

93, published by the American Society for Testing and Materials, 1916 Race St.,

Philadelphia, Pa. 19103.

This report is printed on paper that contains a minimum of 50% recycled

material.
Special Report 96-3

Sampling Trace-Level Organics

with Polymeric Tubings

Louise V. Parker and Thomas A. Ranney February 1996

(revised October 1996)

Prepared for

U.S. ARMY ENVIRONMENTAL CENTER

SFIM-AEC-ET-CR-95072

Approved for public release; distribution is unlimited.

US Army Corps


of Engineers

Cold Regions Research &


Engineering Laboratory
PREFACE

This report was prepared by Louise V. Parker, Research Physical Scientist, Applied Research Division, Research and Engineering Directorate, U.S. Army Cold

Regions Research and Engineering Laboratory (CRREL) and Thomas A. Ranney,

Staff Scientist, Science and Technology Corporation, Hanover, New Hampshire.

Funding for this work was provided by the U.S. Army Environmental Center

(USAEC), Aberdeen Proving Ground, Maryland, Martin H. Stutz, Project Monitor.

The authors thank Martin Stutz and USAEC for their support of this work. They

also thank Franceska D. Wilde, Ground-water Quality Hydrologist, U.S. Geological

Survey National Center, Reston, Virginia, and Dr. Clarence L. Grant, Chemistry Professor Emeritus, University of New Hampshire, Durham, New Hampshire, for their

technical reviews of this manuscript.

This publication reflects the personal views of the authors and does not suggest

or reflect the policy, practices, programs, or doctrine of the U.S. Army or Government of the United States. The contents of this report are not to be used for advertising or promotional purposes. Citation of brand names does not constitute an official

endorsement or approval of the use of such commercial products.

ii
CONTENTS

Preface ...................................................................................................................................... ii

Introduction............................................................................................................................. 1

Literature review .................................................................................................................... 1

Leaching of organic constituents .................................................................................... 1

Sorption of organic contaminants ................................................................................... 2

Research study ........................................................................................................................ 4

Purpose of study ................................................................................................................ 4

Materials and methods ..................................................................................................... 4

Results and discussion .......................................................................................................... 6

Sorption studies ................................................................................................................. 6

Leaching study ................................................................................................................... 10

Conclusions ............................................................................................................................. 11

Literature cited ........................................................................................................................ 11

Appendix A: Test results ....................................................................................................... 15

Appendix B: Analyte losses .................................................................................................. 31

Abstract .................................................................................................................................... 33

ILLUSTRATION

Figure

1. Sorption of analytes by tubing materials ..................................................................... 7

TABLES

Table

1. Polymeric tubing used in sampling trace-level organics ........................................... 5

2. Method detection limits for analytes used in the tubing material study ................ 6

3. Summary of sorption study ............................................................................................ 9

4. Estimated percent loss of PCE and PDCB after 5 and 10 minutes’ contact with

selected tubing materials ......................................................................................... 9

5. Number of spurious HPLC peaks found during tubing material study and

possible identification .............................................................................................. 10

iii
Sampling Trace-Level Organics with Polymeric Tubings

LOUISE V. PARKER AND THOMAS A. RANNEY

INTRODUCTION

It is important that the reported concentrations

of contaminants in samples taken from groundwater monitoring wells accurately reflect in-situ

values. Recent studies suggest that, among currently used sampling methods, low-flow-rate

(~100 mL/min) purging and sampling may cause

the least disturbance to the well during the sampling process. Samples taken using this method

have lower turbidity (Kearl et al. 1992, Puls et al.

1992, Puls and Powell 1992, Backhus et al. 1993)

and yield perhaps the most accurate values for

inorganic contaminants (Puls and Powell 1992,

Puls et al. 1992). There is some evidence that indicates that low-flow-rate purging and sampling

may also produce samples that reflect the true insitu values of at least some organic contaminants,

such as polycyclic aromatic hydrocarbons (Backhus et al. 1993).

One concern about the slow-rate pumping

methods for sampling groundwater is that there

may be interactions between the sampling tubing

(which can be several hundred feet in length) and

the sample as it is pumped to the surface. The

tubing could either leach inorganic or organic

contaminants, thereby giving inaccurate high

values, or sorb these contaminants from the sample, thus giving inaccurate low values. Also, if

pump tubing is not dedicated to a particular well,

it is possible that tubing that was used previously

to sample a well with high concentrations of contaminants would release sorbed contaminants

into the next sample, thereby giving inaccurate

high values. The diffusion of gases, especially

oxygen, through the tubing may also affect the

sample as it is pumped to the surface (Holm et al.

1988, Kjeldsen 1993). In this paper we will focus on

the biases caused by sorption of organic analytes

by polymeric tubings and leaching of organic constituents from these tubings.

LITERATURE REVIEW

When assessing these studies it is important to

differentiate between flexible and rigid formulations of the same polymer, and to note whether the

material that was tested was actually sampling

tubing. This is because the formulations can vary

between different products made of the same

polymer and between flexible and rigid formulations of the same polymer, especially polyvinyl

chloride (PVC). It is also useful to note whether a

biocide was used. This is especially true for sorption studies that last several days or longer, because losses of analytes could be due to biodegradation rather than by sorption by the polymer.

For the purpose of clarity in this review, we will

discuss separately those studies that were conducted using polymeric products other than tubings.

Leaching of organic constituents

With respect to leaching, the importance of discerning between rigid and flexible formulations is

most clearly shown with PVC. Several studies (Jaeger and Rubin 1970 and 1972, Junk et al. 1974,

Christensen et al. 1976, Fayz et al. 1977, Barcelona

et al. 1985) have shown that flexible PVC (FPVC)

products leach considerable quantities of phthalate ester plasticizers into a variety of fluids (blood,

plasma, saline, water). However, this has not been

observed with rigid PVC (RPVC) (Miller 1982,

Curran and Tomson 1983, Ranney and Parker
1994). Much of the reason for this difference is

that the plasticizer content of FPVC ranges from

30 to 50% by weight (Junk et al. 1974, Aller et al.

1989), while RPVC contains virtually no plasticizers (<0.01%) (Barcelona et al. 1984).

Leaching studies that tested tubings

Junk et al. (1974) tested several plastic tubings

to determine if they leached organic constituents

when water was pumped through them. The materials they tested included rigid polyethylene

(PE), rigid polypropylene (PP), black latex, and

six formulations of FPVC tubing. They found that

all the tubings leached constituents even though

they had been prerinsed. Leached concentrations

were the highest from a food- and beveragegrade FPVC and were much lower (three orders

of magnitude) from laboratory-grade FPVC, PP,

and PE tubings. They noted that most (50–90%) of

the total contamination was due to the leaching of

only a few (4–6) constituents. Many of the contaminants that leached from the PVC and black

latex tubing were identified as plasticizers and

other additives. However, they were unable to

identify the major contaminants that leached

from the PE and PP tubing. They also found that

the amount of contamination leached from the

PVC tubing was related to the linear velocity of

the water flowing through the tubing, with more

contamination occurring at the higher flow rates.

They suggested that this was due to an erosion

mechanism occurring at the polymer/water interface at the higher flow rates. They found that

although an initial flushing of PVC tubing with

water had a salutary effect in lowering contaminant leaching, extensive washing served no useful purpose. They concluded that FPVC tubing

contained a nearly inexhaustible supply of contaminants because of its high concentration of

plasticizers, but that this would not be the case

for PE and PP tubings.

Curran and Tomson (1983) compared the

leachates from PP, PE, polytetrafluoroethylene

(PTFE, a type of Teflon), and FPVC (Tygon) tubings and RPVC (pipe). They found that PTFE did

not leach any detectable organic contaminants.

Leachate concentrations were highest from the

FPVC tubing. They noted that the total amount of

contaminants leaching from the PE and PP tubings was less than Junk et al. (1974) had observed.

They felt that this may have been because of differences in flow rate, tubing conditioning, or

manufacturing.

Barcelona et al. (1985) looked at a variety of

tubings: silicone rubber, linear polyethylene

(which, according to Charrier [1990], is high-density PE [HDPE]), PP, FPVC, and PTFE. They found

that all but the PTFE leached significant amounts

of organic carbon in 30 minutes. The FPVC and

silicone rubber tubings leached the most.

Devlin (1987) was unable to detect any constituents leaching into water pumped through an

unspecified type of fluoropolymer (Teflon) tubing or PE tubing.

Leaching studies of polymeric products

other than tubing

Miller (1982) was unable to detect any organic

constituents leaching from two rigid materials:

low-density PE (LDPE) and PP (purchased directly from the plastics manufacturer).

In a static study conducted by this laboratory

(Ranney and Parker 1994), no organic constituents were detected leaching into water from either PTFE (well casings) or fluorinated ethylene

propylene (FEP) (sampling pipe). (These test

solutions were analyzed using reversed-phase

high-performance liquid chromatography (RPHPLC) analyses. In most of the previous studies,

samples were concentrated and analyzed by gas

chromatography-flame ionization detection [GCFID], or GC-FID and gas chromatography-mass

spectrometry [GC-MS].)

Summary of the leaching studies

These studies show that FPVC and rubber tubings leach substantial quantities of organic constituents, and that leaching tends to be less from

the more rigid formulation (e.g., PE and PP). The

fluoropolymers tested (PTFE, FEP) do not appear

to leach any constituents. For at least one polymer (FPVC), higher flow rates increase leaching,

possibly due to erosion of the polymer matrix.

Sorption of organic contaminants

With respect to sorption, again the importance

of differentiating between flexible products and

rigid products has been demonstrated with PVC.

Gillham and O’Hannesin (1990) found FPVC tubing was much more highly sorptive of organic

solutes than RPVC (pipe). As an example, there

was no loss of benzene after one hour in samples

exposed to RPVC, but there was approximately a

55% loss in samples exposed to FPVC tubing.

Sorption studies that tested tubings

A field study by Pearsall and Eckhardt (1987)

documented that concentrations of two volatile

2
organic compounds (VOCs) (1,2-dichloroethylene

and trichloroethylene [TCE]) were substantially

lower in samples pumped through silicone rubber

tubing than those pumped through a type of fluoropolymer tubing. (Flow rates were ∼0.7 to 1.0 L/

min.)

Several laboratory studies have also documented that sampling tubings can sorb organic

solutes. Curran and Tomson (1983) found that 50-

ft lengths of PP, PE, and a fluoropolymer sorbed

very little naphthalene or p-dichlorobenzene

from low-ppb-level aqueous solutions pumped

through them. In contrast, the FPVC tubing

(Tygon) sorbed ~50% of these analytes from solutions pumped through it.

Ho (1983) found that the recovery of nine halogenated VOCs (alkanes and alkenes) from an

aqueous test solution was always lower in samples taken using medical-grade silicone rubber

than in samples taken using PTFE tubing. (Flow

rates varied from 2.6 L/min to 4.0 L/min.)

In a static study, Barcelona et al. (1985) exposed

five common tubings (PP, PE, FPVC, PTFE, and silicone rubber) to a solution containing ppb levels of

chloroform and to an aqueous solution containing

a mixture of four organics (chloroform, trichloroethane, TCE, and tetrachloroethylene [perchloroethylene or PCE]), each at ppb levels. In both experiments, they found that PTFE was the least

sorptive material and that the FPVC and silicone

rubber tubings were the most sorptive. For example, these tubings sorbed 80% of the chloroform

within one hour.

Barcelona et al. (1985) also tested the effect of

additional organic carbon (low ppm levels of

polyethylene glycol) on sorption. They found that

additional organic carbon affected sorption differently depending on the polymer. For example, significant decreases in the sorption of chloroform

were observed for PP and PE, but sorption was

greater for FPVC and silicone rubber.

Barcelona et al. (1985) noted that sorption by

the FPVC and PP tubings was at least two orders

of magnitude greater than Miller (1982) had observed for RPVC and PP materials. They felt that

the higher density and greater crystallinity of

PTFE, PP, and PE may explain why these materials were generally more inert in their study. They

concluded that sorption of chlorinated organic

solvents from aqueous solutions by flexible tubing

materials occurs by absorption into the polymer

matrix. They concluded that flexible materials,

such as silicone rubber and FPVC tubing, represent a virtual sink for chlorinated solvent sorbates.

In a laboratory study, Devlin (1987) found that

when a test solution containing a suite of ppb-level

VOCs was pumped through PE and Teflon (fluoropolymer) tubings, PE tubing was more sorptive.

Devlin also noted that after flushing the two systems with 2 L of the test solution, concentrations of

the analytes in samples taken from either type of

tubing were equivalent. However, Devlin noted

that a larger amount of test solution was required

to “equilibrate” the tubings for two of the analytes

(tetrachloroethane [both tubings] and chlorobenzene [PE tubing]).

The results from Devlin’s field studies, however, do not show a consistent trend. At one site,

concentrations of contaminants in the samples taken using the fluoropolymer tubing were virtually

identical to those taken with PE tubing, while at

other sites concentrations of contaminants were

~30 to 50% higher in samples collected using the

PE tubing.

Sorption studies of polymeric products

other than tubing

Miller (1982) compared sorption of low ppb levels of six volatile organics (bromoform, PCE, TCE,

trichlorofluoromethane, 1,1,1-trichloroethane, and

1,1,2-trichloroethane) by three polymeric materials: RPVC, LDPE, and PP. These products were

purchased directly from the plastics manufacturer.

RPVC was by far the least sorptive of these three

materials and LDPE was the most sorptive polymer tested.

Reynolds and Gillham (1985) compared sorption of ppb levels of five halogenated aliphatic

organic compounds (1,1,1-trichloroethane, 1,1,2,2-

tetrachloroethane, hexachloroethane, bromoform,

and PCE) by six polymeric materials. The polymers they tested included RPVC rod and a polyamide (nylon) plate, and four types of tubing: PTFE,

LDPE, PP, and latex rubber. They found that LDPE

and latex rubber were the most sorptive polymers

tested. A 10% loss of all five analytes was seen

within the first five minutes for samples exposed

to rubber and for four of the analytes exposed to

the LDPE. RPVC and PTFE were the least sorptive

materials; it generally took days to weeks to see a

10% loss with these materials.

For all these polymers, Reynolds and Gillham

(1985) attributed losses to absorption within the

polymer matrix. They were able to successfully

model loss as a function of the partition coefficient

of the organic compound between the aqueous

solution and the polymer (K), the diffusion coefficient in the polymer (D), time, and surface area.

3
Gillham and O’Hannesin (1990) compared

sorption of low ppm levels of six monoaromatic

hydrocarbons (benzene, toluene, ethylbenzene,

and m-, o-, and p-xylene) by seven materials used

in sampling groundwater wells. The materials included stainless steel (SS) tubing, RPVC pipe,

FPVC tubing, PTFE tubing, polyvinylidene fluoride (PVDF) rectangular wire, epoxy-impregnated

fiberglass (FG) tubing, and flexible PE tubing.

They found that flexible tubings, PE and FPVC,

showed the highest rates of uptake, with significant losses (10% or more) of all six compounds

within the first five minutes. They found the more

rigid polymeric products were much less sorptive,

and SS did not sorb any of the analytes. They

ranked the materials from most sorptive to least

sorptive as follows: FPVC > PE > PTFE > PVDF > FG

> RPVC > SS. For the rigid polymeric products,

they found that sorption agreed well with their

diffusion model (described previously by Reynolds and Gillham [1985]).

Studies by our laboratory (Parker et al. 1990,

Parker and Ranney 1994) have also shown that

RPVC well casings were less sorptive of a suite of

organic solutes than PTFE well casings and that

SS well casings did not sorb any of the analytes

tested. These studies also showed that the relative

rate of sorption by PTFE and RPVC was not affected by concentration, i.e., ppb vs. ppm levels.

Summary of sorption studies

From these studies, it appears that rigid tubings are much less sorptive of organic solutes than

flexible tubings. Two of the most sorptive tubings

were FPVC and silicone rubber. PTFE was among

the least sorptive polymeric tubings tested,

although SS products have been shown to be nonsorptive of organic solutes.

RESEARCH STUDY

Purpose of study

The previous studies show that flexible tubing

materials can affect analyte concentrations by

sorbing organic contaminants and by leaching organic constituents. This is especially true for

FPVC. The fluoropolymers were among the least

sorptive tubings tested but were still highly sorptive of some organic solutes. A comprehensive

comparison of the many tubings that are commercially available, especially for the various types of

fluoropolymers that are now available, does not

exist.

The purpose of this study was to compare sorption of organic solutes by twenty of the sampling

tubings that are commercially available and to

look for leaching of contaminants from these materials. The tubings we selected are given in Table

1, where they are categorized by their flexibility.

Thirteen tubings were very flexible and thus nonrigid (i.e., easy to collapse with only finger pressure), and seven tubings were slightly flexible

(coilable) but rigid (i.e, a person could stand on the

tubing without collapsing the tubing). Table 1 also

gives the abbreviations for the polymers tested,

and the tubings’ dimensions and cost. Cost of the

tubings used in this study ranged from $19 (LDPE)

to $870 (fluoroelastomer) per 100 ft.

Materials and methods

Initial sorption study

The test solution for this study consisted of

mg/L concentrations of eight organic compounds: nitrobenzene (NB), trans–1,2-dichloroethylene (TDCE), m-nitrotoluene (MNT), trichloroethylene (TCE), chlorobenzene (CLB), o-dichlorobenzene (ODCB), p-dichlorobenzene (PDCB),

and tetrachloroethylene (PCE). The test solution

was prepared by using a microliter syringe to add

a volume of neat organic solvent directly to well

water (taken from a deep water well in Hartland,

Vermont) contained in a 2-L glass bottle. Mercuric

chloride was added to the solution (40 mg/L) to

prevent any losses due to biological activity. After

adding all of the analytes, the bottle was filled to

capacity with well water to eliminate any headspace, capped with a glass stopper, tightly

wrapped with parafilm, and stirred for two days

using a magnetic stirring device. Prior to pouring

the solution into the tubings, we examined the solution using a magnifying glass to make certain

that there were not any undissolved droplets of

organic solvents in the mixed test solution. The

initial concentrations of the organic solutes varied

from 10 to 16 mg/L (Table A1).

The twenty tubings were cut into different

lengths so that they would all have the same internal surface area, 40 cm2 (Table 1). This was necessary because three types of tubing (PTFE, ethylene

tetrafluoroethylene [ETFE], and polyamide) had

different internal diameters than the other tubings

(Table 1). The tubing surface-area-to-solution-volume ratios and the solution-volume-to-materialvolume ratios differed for these three materials

and for one material (FEP-lined PE), which had a

different wall thickness (Table 1).

The cut tubing sections were rinsed with sev4
5

Table 1. Polymeric tubing used in sampling trace-level organics.

Surface-areaCost to-solutionper foota Dimensions (cm) Length volume ratio

($) I.D. O.D. wall (cm) (cm–1)

Flexible polymersb

polyproplyene-based material with plasticizer, (formulation 1) 0.58 0.64 0.95 0.16 20 6.3

polypropylene-based material with plasticizer, (formulation 2) 2.48 0.64 0.95 0.16 20 6.3

polyvinylchloride (PVC) 0.89 0.64 0.95 0.16 20 6.3

thermoplastic elastomerc (TPE) 0.96 0.64 0.95 0.16 20 6.3

linear copolymer of vinylidene fluoride and

hexafluoropropylene P(VDF-HFP) 1.99 0.64 0.80 0.08 20 6.3

polyurethane 0.64 0.64 0.95 0.16 20 6.3

fluoroelastomer 8.70 0.64 0.95 0.16 20 6.3

Rigid polymersd

polyethylene, low density (LDPE) 0.19 0.64 0.95 0.16 20 6.3

polyethylene, cross-linked high density (XLPE) 0.43 0.64 0.95 0.16 20 6.3

polyethylene liner in ethyl vinyl acetate shell 0.57 0.64 0.95 0.16 20 6.3

polyethylene liner cross-linked to ethyl vinyl acetate shell 1.08 0.64 0.95 0.16 20 6.3

co-extruded polyester lining in PVC shell 0.77 0.64 0.95 0.16 20 6.3

polypropylene (PP) 0.27 0.64 0.95 0.16 20 6.3

polyamide (nylon) 0.71 0.71 0.95 0.12 18 5.6

polytetrafluoroethylene (PTFE) 4.27 0.75 0.95 0.10 17 5.3

perfluoroalkoxy (PFA) 5.58 0.64 0.95 0.16 20 6.3

ethylene tetrafluoroethylene (ETFE) 5.50 0.48 0.64 0.08 27 8.4

polyvinylidene fluoride (PVDF) 1.80 0.64 0.95 0.16 20 6.3

fluorinated ethylene-propylene (FEP) 3.90 0.64 0.95 0.16 20 6.3

FEP-lined polyethylene 3.00 0.64 0.80 0.08 20 6.3

a Cost varies with quantity, dimensions, and supplier.

b Finger pressure can collapse tubing.

c Styrene-ethylene-butylene block copolymer modified with silicon oil.

d Can be stepped on without collapsing the tubing.

loss of the analytes during the filling process, the

solutions in these vials served as controls and thus

were used to determine the initial analyte concentrations for each sampling time.

When it was time to sample a tubing, one of the

plugged ends of the tubing was cut with a special

cutter for rigid tubings and then a Pasteur pipet

was used to transfer an aliquot of the test solution

to a 1.8-mL HPLC autosampler vial. The control

solutions were removed from the refrigerator and

allowed to warm before analysis.

Analytical determinations were performed using RP-HPLC. A modular system was employed

consisting of a Spectra Physics SP8875 autosampler with a 100-μL injection loop, a Spectra Physics

SP8810 isocratic pump, a Spectra Physics SP8490

variable wavelength detector set at 215 nm, and a

Hewlett Packard 3396 series II digital integrator.

Separations were obtained on a 25-cm × 0.46-cm (5

μm) LC–18 column (Supelco) eluted with 65/35

(V/V) methanol/water at a flow rate of 2.0 mL/

min. The detector response was obtained from the

digital integrator operating in the peak height

mode.

For each analyte, a single compound standard

was made by adding the neat (undiluted) comeral volumes of deionized water and left to air-dry.

One end of each of the tubings was plugged with a

glass rod whose diameter matched the internal

diameter of the tubing. The glass rod was inserted

in the tubing to a depth of 1 cm, and then the outside of the tubing was clamped with a plastic tubing clamp. (The length of the glass plugs was taken

into account when figuring the surface areas and

solution volumes.) For each type of tubing, there

were five sampling times (1, 8, 24, 48, and 72 hours)

and two replicates for each sampling time (i.e., 10

tubing pieces of each material).

For each sample time, the tubings were filled in

random order using a glass re-pipettor. The top of

the tubings was sealed immediately after filling by

inserting a glass plug, leaving no head space, and

then clamped as described previously. The tubings

were stored in the dark at room temperature. During this process, three high-performance liquid

chromatography (HPLC) autosampler vials (1.8

mL) were filled with the test solution at the beginning and at the end of filling each set of tubings

(i.e., for each time period). The vials were filled so

there was no headspace, capped with Teflon-lined

plastic caps, and stored in the dark in a refrigerator. Because we anticipated there would be some
pound to methanol contained in a 50-mL glass

volumetric flask on a balance so that the concentration was approximately 2000 mg/L. A combined standard (∼200 mg/L for each analyte) was

made by pipeting 10 mL of each single compound

standard into a 100-mL glass volumetric flask partially filled with methanol and then bringing to

volume with methanol. These standards were

kept in a freezer. Working standards (∼10 mg/L)

were made by pipeting 5 mL of the combined

standard (warmed to room temperature) into a

50-mL glass volumetric flask partially filled with

deionized water, then bringing to volume with

deionized water. This working standard was serially diluted in deionized water, giving standards

of approximately 1.00, 0.100, and 0.0100 mg/L for

each analyte. These working standard solutions

were made fresh each sampling period and run in

triplicate. The method detection limits (MDL) for

the analytes (Table 2) were obtained according to

the EPA protocol described elsewhere (Federal

Register 1984).

Second sorption study

Because three of the tubings used in this study

(PTFE, ETFE, and polyamide) had different surface-area-to-solution-volume ratios than the other

tubings, this study was conducted so that we

could compare sorption of organic solutes by

these tubings with the other seventeen tubings.

In this study, 5-cm pieces of the three tubing

types were placed in three different-sized glass vials (9, 25, and 40 mL). The test solution was made

of the same organic compounds and in the same

manner as in the previous study. The solution was

poured into the vials so there was no headspace,

and the vials were capped with Teflon-lined plastic caps. The total surface-area-to-solution-volume

ratios for PTFE were 0.70, 1.15, 3.55; for ETFE, 0.45,

0.74, and 2.15; and for nylon, 0.69, 1.14, and 3.59.

Samples were taken after one hour, eight hours,

and 24 hours. There were duplicates for each sample time and tubing type. The same-sized vials (9,

25, and 40 mL) filled with test solution (without

tubing) served as controls. The controls were used

6

Table 2. Method detection limits (MDL) for analytes used in the tubing

material study.

MDL MDL

Analyte (mg/L) Analyte (mg/L)

nitrobenzene (NB) 0.0017 chlorobenzene (CLB) 0.0017

trans-1,2-dichloroethylene (TDCE) 0.0019 o-dichlorobenzene (ODCB) 0.0056

m-nitrotoluene (MNT) 0.0022 p-dichlorobenzene (PDCB) 0.0086

trichloroethylene (TCE) 0.0032 tetrachloroethylene (PCE) 0.0035

to account for any losses due to volatiles leaking

through loose caps or sorption by the glass vials,

Teflon liners, or plastic caps. There were two controls for each size vial and sampling time. All samples were kept in the dark at room temperature.

When it was time to take a sample, an aliquot of

each sample was transfered from each of the test

vials to an autosampler vial using a Pasteur pipet.

Analysis was performed as described previously.

Analysis of leachates

Several of the chromatograms for solutions

exposed to the various tubings contained spurious

peaks. Thus, leaching of some type of constituents

occurred in samples exposed to nine types of tubing. In order to determine what some of these contaminants were, we analyzed one of each of the

final (72 hr) samples for each of the twenty tubings

for semivolatile organics using GC-MS. Two GCMS systems were used, each with a different column. The first system consisted of a Hewlett Packard (HP) 5890 series II gas chromatograph and an

HP 5970 mass selective detector with an HP–1 capillary column, 25-m ×0.2-mm ID (0.33 μm). The

second GC-MS system consisted of an HP 5890

series II gas chromatograph, an HP 5972 mass

selective detector, and an HP 7673 auto-injector

with an HP–5 capillary column, 30-m ×0.25-mm

ID (0.25 μm). Operating parameters were the same

on both instruments: initial column temperature of

60°C (hold 1 min.), then ramp to 300°C at 6°C/

min. (hold 19 min.). The injector/detector temperatures were 250°C and 300°C, respectively. Carrier

gas was helium with a linear velocity of 20 cm/s

set at 60°C. For the first instrument, 3 μL were injected manually, while for the second instrument, 1

μL was injected by auto injection. Both injections

had a splitless hold time of 45 sec. Mass scan was

from 45 to 550.

RESULTS AND DISCUSSION

Sorption studies

For the first study, the data for all the replicates

for each analyte, tubing, and time can be found in
7

b. TDCE

e. CLB

f. ODCB

c. MNT g. PDCB

a. Nitrobenzene

Figure 1. Sorption of analytes by tubing materials. (Values for PTFE, ETFE, and polyamide were adjusted to

comparable surface-area-to-solution-volume ratios.)

d. TCE h. PCE

FEP

FEP lining in PE shell

Fluoroelastomer

PVDF

Plasticized PP (formulation 2)

TPE

PVC

P(VDF-HFP)

Polyamide

Plasticized PP (formulation 1)

ETFE

Polyurethane

PFA

PTFE

PP

Polyester lining in PVC shell

PE cross linked to EVA shell

PE lining in EVA shell

XLPE

LDPE

0

1.2

1.0

0.8

0.6

0.4

0.2

20 40 60 80

Relative Concentration

FEP

FEP lining in PE shell

Fluoroelastomer

PVDF

Plasticized PP (formulation 2)

TPE

PVC

P(VDF-HFP)

Polyamide

Plasticized PP (formulation 1)

ETFE

Polyurethane

PFA

PTFE

PP

Polyester lining in PVC shell

PE cross-linked to EVA shell

PE lining in EVA shell

XLPE

LDPE

0

1.2

1.0

0.8

0.6

0.4

0.2

20 40 60 80

Relative Concentration

FEP

FEP lining in PE shell

Fluoroelastomer

PVDF

Plasticized PP (formulation 2)

TPE

PVC

P(VDF-HFP)

Polyamide

Plasticized PP (formulation 1)

ETFE

Polyurethane

PFA

PTFE

PP

Polyester lining in PVC shell

PE cross-linked to EVA shell

PE lining in EVA shell

XLPE

LDPE

0

1.2

1.0

0.8

0.6

0.4

0.2

20 40 60 80

Relative Concentration

FEP

FEP lining in PE shell

Fluoroelastomer

PVDF

Plasticized PP (formulation 2)

TPE

PVC

P(VDF-HFP)

Polyamide

Plasticized PP (formulation 1)

ETFE

Polyurethane

PFA

PTFE

PP

Polyester lining in PVC shell

PE cross-linked to EVA shell

PE lining in EVA shell

XLPE

LDPE

0

1.2

1.0

0.8

0.6

0.4

0.2

20 40 60 80

Contact Time (hr)

Relative Concentration

FEP

FEP lining in PE shell

Fluoroelastomer

PVDF

Plasticized PP (formulation 2)

TPE

PVC

P(VDF-HFP)

Polyamide

Plasticized PP (formulation 1)

ETFE

Polyurethane

PFA

PTFE

PP

Polyester lining in PVC shell

PE cross-linked to EVA shell

PE lining in EVA shell

XLPE

LDPE

0

1.2

1.0

0.8

0.6

0.4

0.2

20 40 60 80

Relative Concentration

FEP

FEP lining in PE shell

Fluoroelastomer

PVDF

Plasticized PP (formulation 2)

TPE

PVC

P(VDF-HFP)

Polyamide

Plasticized PP (formulation 1)

ETFE

Polyurethane

PFA

PTFE

PP

Polyester lining in PVC shell

PE cross-linked to EVA shell

PE lining in EVA shell

XLPE

LDPE

0

1.2

1.0

0.8

0.6

0.4

0.2

20 40 60 80

Relative Concentration

FEP

FEP lining in PE shell

Fluoroelastomer

PVDF

Plasticized PP (formulation 2)

TPE

PVC

P(VDF-HFP)

Polyamide

Plasticized PP (formulation 1)

ETFE

Polyurethane

PFA

PTFE

PP

Polyester lining in PVC shell

PE cross-linked to EVA shell

PE lining in EVA shell

XLPE

LDPE

0

1.2

1.0

0.8

0.6

0.4

0.2

20 40 60 80

Relative Concentration

FEP

FEP lining in PE shell

Fluoroelastomer

PVDF

Plasticized PP (formulation 2)

TPE

PVC

P(VDF-HFP)

Polyamide

Plasticized PP (formulation 1)

ETFE

Polyurethane

PFA

PTFE

PP

Polyester lining in PVC shell

PE cross-linked to EVA shell

PE lining in EVA shell

XLPE

LDPE

0

1.2

1.0

0.8

0.6

0.4

0.2

20 40 60 80

Contact Time (hr)

Relative Concentration
Table A1. For each analyte and time, analysis of

variance (ANOVA) tests were conducted to determine if the tubings had any significant effect (at

the 95% confidence level) on the analyte concentrations. When significant differences were found,

Fisher’s Protected Least Significant Difference

Test was performed to determine which tubing

materials were significantly different from the

controls and each other. The results of these analyses can be seen in Table A2. Because three of the

tubing materials (PTFE, ETFE, and the polyamide

[nylon]) had different material surface-area-tosolution-volume ratios than the other tubing materials, the data for these tubings were marked

with an asterisk.

Mean normalized concentration values were

derived (Table A3) by taking the mean concentration of a given analyte exposed to a given tubing

at a given sampling time and dividing it by the

mean concentration for the control samples for the

same analyte and time. Thus a mean normalized

value of 1.00 represents no loss of analyte for a

given tubing and time.

A second study was conducted so that sorption

of the analytes by the three tubings with different

surface-area-to-solution-volume ratios could be

compared with the other seventeen tubings. This

study compared sorption of the same analytes by

the three tubings with three different surface-areato-solution-volume ratios. The results from this

study can be found in Table A4. These data show

that the material surface-area-to-solution volume

does affect sorption and that, as this ratio increases, sorption of the more hydrophobic analytes also

increases. Normalized values were derived as described previously and are given in Table A5.

(Also included in Table A5 are the normalized values from the previous study for these three materials. This gave us a fourth surface-area-tosolution-volume ratio for comparison.) The best

fit equation was obtained for these data for each

material, analyte, and time using Cricket Graph

software. These equations were then used to

determine what the adjusted normalized values

would have been for these three materials if the

surface-area-to-solution volume had been the

same as the other seventeen tubings. This meant

that we had to extrapolate values for PTFE and

the polyamide and interpolate values for ETFE.

These adjusted normalized values can be found in

Table A3, in parentheses next to the original mean

normalized values. For each analyte, the mean

normalized concentrations have been plotted for

all 20 materials in Figures 1a-h. These figures

show the adjusted mean normalized concentrations for the three materials that had different

surface-area-to-volume ratios (PTFE, ETFE, and

the polyamide).

As we have found in previous studies that tested PVC and PTFE well casings (Parker et al. 1990,

Parker and Ranney 1994), the more hydrophobic

analytes—ODCB, PDCB, and PCE—were the

most readily sorbed, and NB and MNT were the

least sorbed analytes. All the tubings sorbed at

least some of the more sorption-prone analytes.

For some tubings, sorption of some organic solutes was very rapid; i.e., losses equalled or exceeded 95% after only a one-hour contact time.

For polyurethane this was true for seven analytes. For FPVC, the silicone-modified thermoplastic elastomer (TPE), and one of the plasticized

PP tubings, it was true for six analytes. For the coextruded polyester lining in a PVC shell and the

other plasticized PP, it was true for five analytes.

For LDPE, cross-linked high-density polyethylene (XLPE), and PE cross-linked to an ethyl vinyl

acetate (EVA) shell, it was true for three analytes.

For the PE liner in an EVA shell, it was true for

two analytes. These ten materials generally were

the most sorptive, and among this group the flexible tubings were the most sorptive. Among all

the flexible materials tested, only the two fluorinated products, the fluoroelastomer and P(VDFHFP), were not highly sorptive.

Using Figures 1a-h and the results from the

ANOVAs and the least significant difference tests

(Table A2), we compiled a summary table showing the least sorptive materials (Table 3). We see

that generally the rigid fluoropolymers (FEP,

FEP-lined PE, PVDF, PTFE, perfluoroalkoxy

(PFA), and ETFE) were the least sorptive. Specifically, PVDF was the least sorptive material for

TDCE, TCE, and PCE. FEP and FEP-lined PE

were the least sorptive materials for the other five

analytes (NB, MNT, CLB, ODCB, and PDCB).

However, even though FEP, FEP-lined PE, and

PVDF were generally the least sorptive materials

tested, they were still highly sorptive of the more

hydrophobic analytes (Fig. 1g and 1h). For example, after 24 hours, losses of PCE and PDCB by

these three materials ranged from approximately

60 to 80%. Clearly, long-term storage of aqueous

solutions of organic compounds in fluoropolymer containers can be problematic.

With respect to shorter contact times, we see

that in the first hour, sorption of PCE and PDCB

by FEP, FEP-lined PE, and PVDF tubings ranged

from approximately 25 to 40%. However, the con8
9

Table 3. Summary of sorption study.

Least sorptive Next least Other less

Analyte tubings sorptive tubings sorptive tubings

NB FEP-lined PE PTFE ETFE

nitrobenzene FEP

PFA

TDCE PVDF FEP PFA

trans-dichloroethylene FEP-lined PE ETFE

MNT FEP-lined PE PFA PTFE

m-nitrotoluene FEP ETFE

TCE PVDF FEP-lined PE ETFE

trichloroethylene FEP PFA

CLB FEP-lined PE PFA PVDF

chlorobenzene FEP ETFE

ODCB FEP-lined PE PFA ETFE

o-dichlorobenzene FEP PVDF

PDCB FEP-lined PE PVDF PFA

p-dichlorobenzene FEP ETFE

PCE PVDF FEP-lined PE PFA

tetrachloroethylene ETFE

FEP

tact time between a groundwater sample and the

tubing used to pump it to the surface would be

considerably shorter than one hour. The actual

contact time will vary depending on the tubing

diameter and flow rate. For the internal diameter

tubing used most often in this study (0.64 cm), the

contact time for a 50-ft well would be ∼5 minutes

and for a 100-ft well it would be ∼10 minutes if

slow flow rate pumping were used (∼100 mL/

min).

Because there are no data for contact times of

less than an hour, we would like to estimate what

the losses might be for these four materials for the

two most readily sorbed analytes (PCE and

PDCB) if the contact time was either five or ten

minutes. Because we were unable to model our

data in a meaningful way for very short contact

times, we used data of Barcelona et al. (1985) to

predict what these losses might be. Barcelona and

co-workers provide us with data on the sorption

of four VOCs by five polymeric tubings (silicone

rubber, FPVC, PE, PP, and PTFE) after five, ten,

and 60 minutes’ contact. We used these data to

determine what percent of the analyte was

sorbed after five and ten minutes compared with

the amount sorbed after 60 minutes for both the

sorptive, flexible tubings and the less sorptive,

more rigid tubings. (An example of these calculations is given in Table B1.) For example, after ten

minutes, losses to the more sorptive tubings they

tested (silicone rubber and FPVC) were approximately 75% of that observed after 60 minutes, and

for the less sorptive tubings (PE, PP, and PTFE),

losses were approximately 60%. These values

were then used to estimate what the percent losses of PCE and PDCB by the four materials used in

our study (polyurethane, FPVC, FEP, and PVDF)

might have been for contact times of five and ten

minutes (Table 4).

While these values are only gross estimates,

they do indicate that for relatively short contact

times (five and ten minutes), sorption of the more

sorptive analytes (PDCB and PCE) by the relatively nonsorptive tubings (FEP and PVDF) can

still be substantial (∼5–25%). For the highly sorptive tubings (polyurethane and FPVC), approximately 45 to 75% of these analytes could be lost in

ETFE = ethylene tetrafluoroethylene

FEP = fluorinated ethylene propylene

PE = polyethylene

PFA = perfluoroalkoxy

PTFE = polytetrafluoroethylene

PVDF = polyvinylidene fluoride

Table 4. Estimated percent loss of PCE

and PDCB after 5 and 10 minutes’ contact with selected tubing materials.*

PCE PDCB

Material 5 min. 10 min. 5 min. 10 min.

FEP 17.0 26.0 12.0 18.0

PVDF 5.6 8.3 16.0 23.0

PUR* 44.0 74.0 44.0 74.0

PVC 44.0 74.0 44.0 74.0

* Values were estimated using the data of Barcelona et al. (1985). An example of these calculations is given in Table B1.

PUR = polyurethane
five to ten minutes. These losses reflect what

might be sorbed by a virgin material. However,

conditions in the tubing are dynamic and fresh

water would be continually replenished as it is

pumped through the system. One might anticipate that once equilibrium is reached, little or no

more losses of analytes would be expected, unless

transfer to the atmosphere through the tubing was

significant. The question that then remains is how

much time is needed for the tubing to reach equilibrium under dynamic conditions. Currently

there are no data available that answer this question.

Leaching study

When we compared the chromatograms of

sample solutions exposed to the tubings with the

control sample solutions, we saw additional

peaks in the solutions exposed to some of the tubings. By the end of the experiment (72 hr), solutions exposed to nine of the tubings had extra or

spurious peaks, most likely indicating that some

constituents had leached (Table 5). The chromatograms for the solutions exposed to the polyurethane, polyamide, and PVC tubings contained at

least eight spurious peaks, with polyurethane

having the most (12). The chromatograms for the

solutions exposed to the polyester-lined PVC shell

10

Table 5. Number of spurious HPLC peaks found during tubing material study

and possible identification.

Contact time (hr) Possible identification

1 72 ( % match )

Flexible tubings

Plasticized PP (formulation 1) 1 1 not identified

Plasticized PP (formulation 2) 0 0

PVC 3 8 hexacosane (90%)

TPE 1 4 hexanedioic acid, dioctyl ester (83%)

P(VDF-HFP) 1 1 not identified

Polyurethane 5 12 hexanoic acid, 2-ethyl (78%)

Fluoroelastomer 1 1 not identified

Rigid tubings

LDPE 0 0

XLPE 0 0

PE in an EVA shell 0 0

PE cross-linked to EVA shell 0 0

Polyester lining in a PVC shell 1 4 not identified

PP 1 1 hexanedioic acid, dioctyl ester (87%)

Polyamide 2 9 benzenesulfonamide, N-butyl (90%)

PTFE 0 0

PFA 0 0

ETFE 0 0

PVDF 0 0

FEP 0 0

FEP-lined PE 0 0

Boldface = Materials that leached several contaminants during the study.

and the silicone-modified TPE tubings had four

spurious peaks, and chromatograms for the solutions exposed to the PP, one of the plasticized

polypropylenes (formulation 1), the P(VDFHFP), and the fluoroelastomer tubings each contained one spurious peak. The chromatograms

for the solutions exposed to the rigid fluoropolymers, the polyethylenes, and one of the plasticized polypropylenes (formulation 2) did not

contain any spurious peaks. This plasticized PP

tubing was the only flexible tubing that did not

appear to leach any contaminants.

One test solution from each of the tubings that

was found to leach contaminants was analyzed

for semivolatile organics by GC-MS. We reported

only those matches where the quality of the

match was greater than 75%. Unfortunately, we

were unable to identify most of the leachates using this method. The sample solutions exposed to

PP and the TPE tubings had one major peak,

which was tentatively identified as hexanedioic

dioctyl ester (90% match). This compound is

commonly used as a plasticizer and lubricant in

the manufacture of polymeric materials. The

polyamide tubing leached one primary contaminant that we tentatively identified as n-butylbenzene sulfonamide (90% match). The GC chromatogram for the sample solutions exposed to
11

the polyurethane tubing had a number of peaks,

but we were unable to identify any of the compounds that leached. The best match was for the

largest peak, which was tentatively identified as 2-

ethyl hexanoic acid, with a 78% match. Hexanoic

acid (caproic acid) is used in the manufacture of

rubber chemicals and resins. The sample solution

exposed to the PVC tubing had one major peak;

hexacosane (a 26-carbon alkane) was a 90% match.

However, we are at a loss to explain its presence

unless it was used as a lubricant. The sample solution exposed to the polyester-lined PVC tubing

had a number of peaks but no good matches.

Based on these findings, the following tubing

materials appear to be least desirable for sampling

organics, since each of them appeared to leach

several contaminants: polyurethane, polyamide,

FPVC, polyester-lined PVC, and silicone-modified

TPE. In addition, PP, plasticized PP (formulation

1), P(VDF-HFP), and the fluoroelastomer tubings

each appeared to leach one contaminant and thus

may be less desirable than those tubings that did

not leach any contaminants (i.e., the PE and rigid

fluoropolymer tubings).

CONCLUSIONS

Based on the results from these studies, the rigid fluoropolymers appear to be the best materials

for sampling groundwater because they were the

least sorptive of organic solutes and do not appear

to leach any contaminants. Among the fluoropolymers, FEP, FEP-lined PE, and PVDF were the least

sorptive materials tested. If one also considers

cost, PVDF is the least expensive of these three

materials: its price was approximately 50–60% of

the FEP and FEP-lined PE tubings. In fact, PVDF

was the least expensive of all the rigid fluoropolymers tested.

In some instances, a more flexible tubing may

be required—for example, in the head of a peristaltic pump. Among the flexible tubings, the two fluorinated tubings (the fluoroelastomer and P[VDFHFP]) were much less sorptive of organic solutes

than the other flexible tubings. In addition, these

two tubings and the two plasticized polypropylenes appeared to leach the fewest constituents.

However, if we also consider cost, we see that the

fluoroelastomer was the most expensive of all the

tubings tested, while the price of the P(VDF-HFP)

tubing was less than 25% of the cost of the fluoroelastomer tubing.

Because all the fluoropolymer tubings tend to

be expensive, a less expensive material would be

desirable if it did not affect sample quality during

the relatively short contact time typical of most

sampling situations. It is possible that the biases

we observed in this study may either increase

or decrease under dynamic conditions. With respect to sorption of organic solutes, we expect that

losses due to sorption would be reduced, or possibly eliminated, with time as equilibrium is

approached. The unanswered question is how

much time is required for equilibration to occur.

Leaching of constituents, however, may increase

or decrease with exposure. Several leaching studies (Packham 1971a,b; Gross et al. 1974, Boettner et

al. 1981) have shown that much of the leaching

that occurs from RPVC pipe decreases with time

and is considered a surface phenomenon. It is possible that leaching of contaminants from other

polymers may also be a surface phenomenon. If

this is the case, we would expect that leaching

would be minimized under dynamic conditions.

On the other hand, if higher flow rates increase

leaching as Junk et al. (1974) observed with FPVC,

then it may be leaching rather than sorption that

dictates which types of tubing are acceptable for

sampling groundwater. Only a series of studies

conducted under dynamic conditions with a suite

of organic contaminants will determine whether

the biases we observed in this study disappear

under dynamic conditions. We are currently conducting studies to address these issues.

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15

APPENDIX A: TEST RESULTS

* Analyses of two 24-hr control samples were not recorded by the integrator.

D–Concentration of analyte was below MDL.

Table A1. Concentration (mg/L) of analyte solutions exposed to various tubing

materials.

Exposure time Analyte

(hr) NB TDCE MNT TCE CLB ODCB PDCB PCE

Controls

1 11.6 10.9 11.4 15.7 12.6 12.2 11.4 13.1

1 11.6 11.0 11.5 16.0 12.8 12.4 11.6 13.4

1 11.7 11.2 11.6 16.2 12.9 12.5 11.7 13.5

1 11.5 10.9 11.4 15.9 12.7 12.3 11.5 13.3

1 11.5 10.7 11.3 15.7 12.6 12.2 11.4 13.0

1 11.8 11.0 11.6 15.9 12.8 12.4 11.6 13.1

 

X 11.61 10.94 11.46 15.91 12.74 12.32 11.53 13.24

8 11.9 12.4 11.8 17.5 13.7 12.8 11.3 14.4

8 10.9 11.0 10.9 16.2 12.3 11.9 11.5 13.4

8 11.2 10.9 11.1 16.0 12.2 11.8 11.4 13.3

8 11.0 11.0 11.0 16.3 12.3 12.0 11.9 14.1

8 11.2 10.9 11.1 16.1 12.3 11.9 11.5 13.7

8 11.2 10.8 11.2 16.0 12.3 12.0 11.4 13.5

 

X 11.25 11.17 11.18 16.36 12.51 12.07 11.50 13.75

24* 11.1 10.2 11.1 15.1 12.1 11.8 11.2 12.2

24 11.3 10.1 11.2 15.0 12.2 11.8 11.0 11.7

24 11.3 10.4 11.2 15.5 12.4 12.0 11.4 12.4

24 11.5 10.2 11.3 15.1 12.2 11.8 11.0 11.8

 

X 11.32 10.25 11.20 15.16 12.21 11.85 11.18 12.02

48 11.5 9.66 11.5 14.4 12.0 11.9 11.1 11.6

48 11.6 9.93 11.6 14.8 12.3 12.1 11.4 12.0

48 11.4 9.47 11.4 14.2 11.9 11.7 10.8 11.2

48 10.9 9.60 10.8 14.1 11.5 11.3 10.6 11.4

48 11.4 9.87 11.4 14.6 12.1 11.9 11.1 11.8

48 11.2 9.17 11.0 13.6 11.4 11.1 10.1 10.4

 

X 11.34 9.616 11.27 14.27 11.89 11.66 10.86 11.39

72 11.3 9.60 11.3 14.3 11.8 11.6 10.9 11.8

72 11.1 9.64 11.1 13.8 11.5 11.3 10.5 11.2

72 11.4 9.59 11.2 14.3 11.8 11.5 10.6 11.5

72 11.3 9.24 11.3 13.8 11.5 11.4 10.6 11.2

72 11.2 9.09 11.2 13.6 11.4 11.3 10.4 11.0

72 11.2 9.24 11.1 13.8 11.6 11.4 10.5 11.2

 

X 11.25 9.401 11.20 13.93 11.61 11.41 10.59 11.32

Polyurethane

1 0.773 0.395 0.431 0.375 0.252 0.241 0.199 0.286

1 0.882 0.406 0.543 0.342 0.231 0.224 0.178 0.228

 

X 0.827 0.401 0.487 0.359 0.242 0.232 0.188 0.257

8 0.294 0.137 0.054 0.075 0.032 0.010 D 0.028

8 0.307 0.124 0.053 0.070 0.032 0.012 D 0.023

 

X 0.301 0.130 0.053 0.072 0.032 0.011 D 0.025

24 0.245 0.036 0.032 0.039 0.018 0.007 D 0.016

24 0.230 0.046 0.030 0.037 0.018 0.006 D 0.028

 

X 0.237 0.041 0.031 0.038 0.018 0.006 D 0.022

48 0.227 D 0.021 0.017 0.013 D D 0.007

48 0.244 D 0.024 0.018 0.014 D D 0.008

 

X 0.236 D 0.022 0.018 0.013 D D 0.007
16

72 0.158 D 0.018 0.011 0.005 D D 0.007

72 0.165 D 0.020 0.013 0.009 0.006 D 0.009

 

X 0.162 D 0.019 0.012 0.007 <0.006 D 0.008

PVC

1 1.22 0.676 0.402 0.451 0.258 0.203 0.169 0.242

1 1.28 0.701 0.401 0.450 0.253 0.191 0.158 0.231

 

X 1.25 0.689 0.402 0.451 0.255 0.197 0.164 0.236

8 0.874 0.238 0.081 0.115 0.049 0.016 0.013 0.036

8 0.960 0.269 0.090 0.130 0.058 0.020 0.016 0.031

 

X 0.917 0.253 0.085 0.122 0.053 0.018 0.015 0.033

24 1.11 0.131 0.054 0.068 0.032 0.011 0.010 0.016

24 1.09 0.129 0.052 0.066 0.031 0.015 0.019 0.019

 

X 1.10 0.130 0.053 0.067 0.031 0.013 0.014 0.018

48 1.35 0.072 0.037 0.046 0.024 0.007 D 0.013

48 1.18 0.158 0.037 0.045 0.022 0.006 D 0.012

 

X 1.26 0.115 0.037 0.045 0.023 0.007 D 0.013

72 0.862 0.035 0.031 0.032 0.017 0.009 D 0.011

72 0.771 0.033 0.028 0.029 0.017 0.007 D 0.017

 

X 0.816 0.034 0.030 0.030 0.017 0.008 D 0.014

TPE

1 1.72 0.454 0.640 0.351 0.239 0.228 0.188 0.237

1 ††††††††

 

X 1.72 0.454 0.640 0.351 0.239 0.228 0.188 0.237

8 0.545 0.119 0.143 0.062 0.034 0.011 D 0.012

8 0.554 0.114 0.139 0.061 0.033 0.012 D 0.012

 

X 0.549 0.116 0.141 0.061 0.034 0.012 D 0.012

24 0.376 0.042 0.080 0.023 0.016 0.007 D 0.006

24 0.373 0.042 0.078 0.021 0.016 0.007 D 0.005

 

X 0.374 0.042 0.079 0.022 0.016 0.007 D 0.005

48 0.244 0.048 0.060 0.008 0.007 D D D

48 0.260 0.048 0.060 0.005 0.006 D D D

 

X 0.252 0.048 0.060 0.006 0.006 D D D

72 0.123 D 0.058 0.007 0.008 D D D

72 0.165 D 0.067 D 0.009 D D D

 

X 0.144 D 0.062 <0.003 0.009 D D D

Plasticized PP (formulation 2)

1 2.48 0.569 0.861 0.369 0.248 0.204 0.165 0.198

1 2.20 0.537 0.749 0.342 0.221 0.182 0.145 0.186

 

X 2.34 0.553 0.805 0.356 0.235 0.193 0.155 0.192

8 0.728 0.164 0.186 0.085 0.045 0.012 0.010 0.009

8 0.760 0.171 0.190 0.083 0.045 0.015 0.009 0.015

 

X 0.744 0.168 0.188 0.084 0.045 0.014 0.010 0.012

24 0.318 0.056 0.089 0.045 0.031 0.010 D 0.005

24 0.329 0.040 0.089 0.045 0.028 0.010 0.010 0.009

 

X 0.324 0.048 0.089 0.045 0.030 0.010 <0.005 0.007

48 0.145 0.004 0.043 0.011 0.011 0.006 D 0.006

48 0.158 0.004 0.045 0.009 0.009 0.006 D 0.006

 

X 0.152 0.004 0.044 0.010 0.010 0.006 D 0.006

72 0.110 D 0.017 0.016 0.010 D D D

72 0.089 D 0.020 0.022 0.015 D D D

 

X 0.100 D 0.019 0.019 0.013 D D D

Table A1 (cont’d). Concentration (mg/L) of analyte solutions exposed to various

tubing materials.

Exposure time Analyte

(hr) NB TDCE MNT TCE CLB ODCB PDCB PCE

† Sample tubing was found incompletely filled with the test solution.

D–Concentration of analyte was below MDL.
17

Table A1 (cont’d).

Exposure time Analyte

(hr) NB TDCE MNT TCE CLB ODCB PDCB PCE

Plasticized PP (formulation 1)

1 2.40 0.587 0.831 0.388 0.256 0.207 0.167 0.212

1 2.47 0.614 0.861 0.412 0.272 0.230 0.188 0.243

 

X 2.44 0.600 0.846 0.400 0.264 0.218 0.177 0.227

8 0.837 0.178 0.220 0.084 0.049 0.016 0.010 0.013

8 0.861 0.185 0.219 0.088 0.049 0.018 0.011 0.015

 

X 0.849 0.181 0.219 0.086 0.049 0.017 0.010 0.014

24 0.426 0.048 0.115 0.043 0.030 0.010 D 0.007

24 0.426 0.045 0.113 0.037 0.026 0.009 D 0.007

 

X 0.426 0.046 0.114 0.040 0.028 0.010 D 0.007

48 0.182 0.008 0.060 0.012 0.011 0.006 D 0.006

48 0.229 0.008 0.068 0.016 0.015 0.007 D 0.005

 

X 0.206 0.008 0.064 0.014 0.013 0.006 D 0.006

72 0.108 D 0.039 0.007 0.011 D D 0.006

72 0.087 D 0.030 D 0.009 D D D

 

X 0.098 D 0.034 <0.003 0.010 D D <0.002

Polyester lining in PVC shell

1 1.54 1.08 0.730 0.837 0.488 0.357 0.293 0.463

1 1.44 1.06 0.618 0.719 0.396 0.251 0.203 0.360

 

X 1.49 1.07 0.674 0.778 0.442 0.304 0.248 0.411

8 0.547 0.547 0.168 0.257 0.109 0.032 0.023 0.068

8 0.518 0.487 0.165 0.234 0.099 0.030 0.022 0.063

 

X 0.533 0.517 0.166 0.246 0.104 0.031 0.023 0.066

24 0.434 0.340 0.125 0.168 0.076 0.026 0.016 0.044

24 0.425 0.319 0.118 0.160 0.072 0.026 0.016 0.039

 

X 0.429 0.329 0.122 0.164 0.074 0.026 0.016 0.041

48 0.338 0.244 0.087 0.116 0.054 0.029 0.013 0.029

48 0.339 0.215 0.091 0.111 0.052 0.029 0.011 0.028

 

X 0.339 0.229 0.089 0.114 0.053 0.029 0.012 0.028

72 0.319 0.166 0.083 0.087 0.042 0.024 0.009 0.026

72 0.307 0.153 0.085 0.084 0.042 0.025 0.010 0.027

 

X 0.313 0.160 0.084 0.085 0.042 0.025 0.010 0.026

LDPE

1 8.37 3.41 4.87 2.22 1.33 0.627 0.430 0.563

1 8.67 3.43 4.97 2.26 1.37 0.655 0.449 0.584

 

X 8.52 3.42 4.92 2.24 1.35 0.641 0.440 0.573

8 6.39 1.71 2.72 0.947 0.523 0.192 0.120 0.170

8 6.14 1.71 2.56 0.922 0.491 0.174 0.110 0.159

 

X 6.26 1.71 2.64 0.934 0.507 0.183 0.115 0.165

24 4.82 0.939 1.705 0.513 0.296 0.109 0.066 0.087

24 4.63 0.924 1.643 0.507 0.291 0.109 0.067 0.084

 

X 4.73 0.931 1.674 0.510 0.294 0.109 0.067 0.086

48 3.82 0.609 1.224 0.332 0.195 0.074 0.045 0.066

48 3.83 0.594 1.215 0.327 0.195 0.072 0.043 0.057

 

X 3.83 0.602 1.220 0.329 0.195 0.073 0.044 0.061

72 3.01 0.385 0.918 0.231 0.143 0.056 0.031 0.041

72 2.89 0.360 0.886 0.218 0.135 0.053 0.032 0.033

 

X 2.95 0.373 0.902 0.225 0.139 0.054 0.031 0.037

XLPE

1 8.55 3.66 5.02 2.47 1.49 0.711 0.494 0.657

1 8.39 3.18 4.59 2.02 1.20 0.508 0.334 0.447

 

X 8.47 3.42 4.80 2.24 1.34 0.609 0.414 0.552

D–Concentration of analyte was below MDL.
18

Table A1 (cont’d). Concentration (mg/L) of analyte solutions exposed to various

tubing materials.

Exposure time Analyte

(hr) NB TDCE MNT TCE CLB ODCB PDCB PCE

8 5.84 1.60 2.33 0.857 0.463 0.164 0.102 0.142

8 6.16 1.80 2.51 0.963 0.533 0.190 0.109 0.177

 

X 6.00 1.70 2.42 0.910 0.498 0.177 0.106 0.160

24 4.57 0.932 1.62 0.511 0.295 0.110 0.066 0.089

24 4.49 0.924 1.58 0.505 0.289 0.105 0.065 0.092

 

X 4.53 0.928 1.60 0.508 0.292 0.108 0.065 0.090

48 3.67 0.585 1.20 0.327 0.198 0.076 0.047 0.059

48 3.63 0.583 1.19 0.328 0.198 0.076 0.048 0.058

 

X 3.65 0.584 1.19 0.327 0.198 0.076 0.048 0.059

72 2.90 0.400 0.908 0.241 0.146 0.057 0.036 0.044

72 2.99 0.380 0.903 0.229 0.088 0.054 0.033 0.038

 

X 2.95 0.390 0.906 0.235 0.117 0.056 0.035 0.041

PE lining in EVA shell

1 8.30 3.19 4.91 2.26 1.41 0.741 0.526 0.668

1 8.44 3.04 4.91 2.06 1.26 0.624 0.432 0.552

 

X 8.37 3.11 4.91 2.16 1.34 0.683 0.479 0.610

8 5.63 0.845 2.23 0.564 0.347 0.142 0.100 0.096

8 5.45 0.819 2.09 0.550 0.327 0.137 0.074 0.118

 

X 5.54 0.832 2.16 0.557 0.337 0.139 0.087 0.107

24 3.45 0.347 1.04 0.230 0.144 0.065 0.032 0.056

24 3.31 0.332 0.972 0.212 0.133 0.058 0.029 0.051

 

X 3.38 0.340 1.01 0.221 0.138 0.062 0.030 0.054

48 1.84 0.182 0.446 0.115 0.071 0.032 0.019 0.036

48 1.64 0.172 0.395 0.106 0.064 0.038 0.024 0.040

 

X 1.74 0.177 0.421 0.110 0.067 0.035 0.021 0.038

72 0.875 0.092 0.206 0.071 0.044 0.027 0.021 0.031

72 0.926 0.089 0.211 0.068 0.042 0.017 0.011 0.021

 

X 0.900 0.090 0.209 0.070 0.043 0.022 0.016 0.026

PE cross-linked to EVA shell

1 8.04 2.95 4.49 2.08 1.29 0.615 0.420 0.556

1 7.92 2.95 4.48 2.06 1.25 0.599 0.407 0.553

 

X 7.98 2.95 4.49 2.07 1.27 0.607 0.414 0.554

8 5.06 0.775 1.93 0.526 0.318 0.140 0.076 0.131

8 5.22 0.796 1.97 0.530 0.326 0.143 0.071 0.136

 

X 5.14 0.786 1.95 0.528 0.322 0.142 0.073 0.133

24 2.73 0.322 0.749 0.192 0.117 0.053 0.027 0.048

24 2.80 0.332 0.780 0.200 0.122 0.058 0.030 0.054

 

X 2.76 0.327 0.765 0.196 0.119 0.055 0.029 0.051

48 1.44 0.191 0.338 0.111 0.065 0.026 0.014 0.033

48 1.41 0.176 0.333 0.107 0.066 0.028 0.019 0.029

 

X 1.42 0.183 0.336 0.109 0.065 0.027 0.016 0.031

72 0.754 0.097 0.184 0.070 0.043 0.020 0.014 0.021

72 0.773 0.106 0.187 0.074 0.044 0.018 0.013 0.025

 

X 0.764 0.102 0.186 0.072 0.043 0.019 0.014 0.023

P(VDF-HFP)

1 7.89 6.87 4.66 7.90 5.09 2.99 2.42 3.51

1 8.17 7.72 4.87 8.83 5.52 3.17 2.61 4.07

 

X 8.03 7.30 4.76 8.36 5.31 3.08 2.51 3.79

8 5.28 5.40 2.25 5.29 2.74 1.24 0.997 1.83

8 5.34 5.35 2.30 5.26 2.73 1.25 1.01 1.83

 

X 5.31 5.37 2.28 5.27 2.73 1.25 1.00 1.83
Table A1 (cont’d).

Exposure time Analyte

(hr) NB TDCE MNT TCE CLB ODCB PDCB PCE

24 4.00 3.64 1.51 3.31 1.77 0.792 0.621 1.01

24 3.92 3.83 1.46 3.44 1.78 0.778 0.606 1.07

 

X 3.96 3.73 1.48 3.37 1.77 0.785 0.614 1.04

48 3.09 2.87 1.06 2.42 1.25 0.534 0.419 0.731

48 3.09 2.93 1.07 2.53 1.29 0.558 0.433 0.784

 

X 3.09 2.90 1.07 2.48 1.27 0.546 0.426 0.758

72 2.32 1.90 0.779 1.60 0.850 0.360 0.275 0.464

72 2.32 2.06 0.776 1.75 0.927 0.387 0.296 0.525

 

X 2.32 1.98 0.778 1.68 0.889 0.374 0.285 0.495

Fluoroelastomer

1 7.09 6.91 3.95 7.43 4.44 2.53 2.08 3.12

1 7.06 6.55 3.82 7.02 4.19 2.32 1.89 2.78

 

X 7.08 6.73 3.88 7.23 4.31 2.42 1.99 2.95

8 4.77 5.33 1.94 4.73 2.37 1.07 0.819 1.52

8 4.53 4.68 1.85 4.29 2.15 1.00 0.828 1.38

 

X 4.65 5.00 1.89 4.51 2.26 1.04 0.824 1.45

24 3.30 3.14 1.24 2.74 1.41 0.650 0.523 0.797

24 3.36 3.29 1.24 2.82 1.44 0.631 0.502 0.782

 

X 3.33 3.21 1.24 2.78 1.42 0.641 0.512 0.790

48 2.72 2.41 0.961 2.06 1.04 0.469 0.368 0.562

48 2.75 2.50 0.974 2.10 1.06 0.487 0.387 0.598

 

X 2.73 2.46 0.968 2.08 1.05 0.478 0.377 0.580

72 2.07 1.63 0.714 1.37 0.748 0.330 0.257 0.369

72 2.11 1.77 0.714 1.46 0.760 0.331 0.262 0.410

 

X 2.09 1.70 0.714 1.41 0.754 0.331 0.259 0.390

Polyamide

1 7.45 6.28 4.67 4.71 2.81 1.15 0.924 2.01

1 8.53 6.39 5.93 5.48 3.47 1.53 1.12 2.45

 

X 7.99 6.34 5.30 5.10 3.14 1.34 1.02 2.23

8 5.05 3.20 2.33 2.14 1.14 0.307 0.251 0.681

8 4.93 3.02 2.24 2.03 1.08 0.295 0.242 0.650

 

X 4.99 3.11 2.29 2.09 1.11 0.301 0.247 0.666

24 3.21 1.79 1.29 1.20 0.729 0.185 0.156 0.373

24 3.33 1.87 1.33 1.22 0.758 0.187 0.154 0.374

 

X 3.27 1.83 1.31 1.21 0.744 0.186 0.155 0.374

48 2.48 1.37 0.991 0.891 0.521 0.147 0.123 0.282

48 2.52 1.38 0.989 0.871 0.513 0.135 0.114 0.274

 

X 2.50 1.38 0.990 0.881 0.517 0.141 0.118 0.278

72 1.98 0.892 0.764 0.670 0.283 0.110 0.092 0.217

72 1.93 0.771 0.730 0.596 0.267 0.100 0.081 0.187

 

X 1.95 0.832 0.747 0.633 0.275 0.105 0.087 0.202

PP

1 10.8 6.18 9.19 6.04 4.53 2.59 1.70 1.92

1 10.9 5.96 9.14 5.57 4.13 2.19 1.37 1.54

 

X 10.8 6.07 9.17 5.81 4.33 2.39 1.53 1.73

8 9.75 3.91 7.20 3.06 2.11 0.958 0.572 0.668

8 9.59 3.90 7.07 3.00 2.05 0.931 0.559 0.662

 

X 9.67 3.90 7.13 3.03 2.08 0.944 0.566 0.665

24 9.02 2.49 5.91 1.81 1.30 0.591 0.341 0.369

24 9.09 2.71 6.09 1.99 1.42 0.638 0.372 0.406

 

X 9.05 2.60 6.00 1.90 1.36 0.615 0.356 0.388

19
Table A1 (cont’d). Concentration (mg/L) of analyte solutions exposed to various

tubing materials.

Exposure time Analyte

(hr) NB TDCE MNT TCE CLB ODCB PDCB PCE

48 8.40 1.71 5.17 1.25 0.951 0.452 0.261 0.286

48 8.49 1.90 5.16 1.35 0.993 0.464 0.265 0.279

 

X 8.45 1.81 5.16 1.30 0.972 0.458 0.263 0.283

72 7.75 1.48 4.33 1.06 0.766 0.355 0.203 0.226

72 7.49 1.33 4.09 0.943 0.687 0.320 0.181 0.197

 

X 7.62 1.40 4.21 1.00 0.727 0.338 0.192 0.211

ETFE

1 11.2 6.68 10.4 9.52 8.33 7.57 5.42 5.87

1 11.0 6.97 10.2 9.90 8.53 7.56 5.35 6.00

 

X 11.1 6.83 10.3 9.71 8.43 7.56 5.38 5.93

8 9.86 4.66 8.57 6.50 5.68 4.74 2.89 3.21

8 10.1 5.03 8.68 6.99 5.84 4.77 2.82 3.53

 

X 9.96 4.84 8.62 6.74 5.76 4.75 2.86 3.37

24 9.24 3.18 7.43 4.29 3.90 3.07 1.59 1.78

24 9.23 3.04 7.41 4.15 3.85 3.02 1.53 1.67

 

X 9.24 3.11 7.42 4.22 3.88 3.04 1.56 1.73

48 8.61 2.30 6.43 3.05 2.80 2.12 1.03 1.21

48 8.52 2.45 6.45 3.23 2.97 2.29 1.14 1.32

 

X 8.56 2.37 6.44 3.14 2.88 2.21 1.09 1.26

72 7.61 1.89 5.29 2.42 2.20 1.59 0.755 0.901

72 7.67 1.75 5.35 2.24 2.06 1.53 0.719 0.841

 

X 7.64 1.82 5.32 2.33 2.13 1.56 0.737 0.871

PTFE

1 11.8 8.64 11.3 11.1 9.94 8.77 6.46 5.58

1 11.5 7.97 11.0 10.1 9.29 8.16 5.84 4.78

 

X 11.6 8.31 11.2 10.6 9.62 8.46 6.15 5.18

8 10.6 6.15 9.60 6.66 6.09 4.92 3.06 2.05

8 10.8 6.14 9.79 6.67 6.19 4.98 3.02 2.05

 

X 10.7 6.15 9.69 6.67 6.14 4.95 3.04 2.05

24 10.6 4.48 9.71 4.68 5.13 3.74 1.98 1.23

24 10.7 4.67 9.84 4.87 5.29 3.84 2.05 1.28

 

X 10.6 4.57 9.77 4.78 5.21 3.79 2.01 1.25

48 10.5 3.34 9.32 3.33 3.89 2.79 1.39 0.840

48 10.5 3.33 9.29 3.33 3.93 2.76 1.37 0.814

 

X 10.5 3.33 9.30 3.33 3.91 2.77 1.38 0.827

72 10.2 2.63 8.82 2.60 3.14 2.19 1.06 0.636

72 10.4 2.84 8.97 2.76 3.28 2.27 1.12 0.694

 

X 10.3 2.74 8.90 2.68 3.21 2.23 1.09 0.665

PFA

1 11.4 9.01 11.2 11.9 10.5 9.48 7.28 6.57

1 11.5 8.47 11.2 11.1 9.97 8.92 6.63 5.65

 

X 11.5 8.74 11.2 11.5 10.2 9.20 6.95 6.11

8 11.0 7.01 10.4 8.24 7.68 6.26 3.93 2.97

8 11.5 7.44 11.1 8.56 8.23 6.71 3.96 3.19

 

X 11.2 7.22 10.7 8.40 7.96 6.49 3.94 3.08

24 11.0 5.16 10.2 5.67 6.07 4.73 2.60 1.64

24 10.9 5.13 10.1 5.59 5.95 4.64 2.55 1.66

 

X 10.9 5.14 10.2 5.63 6.01 4.69 2.57 1.65

48 10.8 4.36 9.97 4.60 5.19 3.91 2.03 1.29

48 11.0 4.39 10.1 4.60 5.21 3.92 2.02 1.28

 

X 10.9 4.37 10.0 4.60 5.20 3.92 2.03 1.29

20
72 10.5 3.32 9.36 3.37 3.99 2.94 1.44 0.882

72 10.7 3.49 9.49 3.52 4.10 3.04 1.51 0.956

 

X 10.6 3.41 9.43 3.45 4.05 2.99 1.48 0.919

PVDF

1 10.1 9.80 8.35 13.7 9.67 7.78 7.01 9.91

1 9.82 9.49 8.26 13.4 9.52 7.76 7.00 9.81

 

X 9.96 9.64 8.31 13.6 9.60 7.77 7.00 9.86

8 8.71 9.53 6.07 12.8 7.53 5.21 4.78 8.45

8 8.63 8.93 6.03 12.0 7.18 5.05 4.66 8.00

 

X 8.67 9.23 6.05 12.4 7.35 5.13 4.72 8.22

24 7.93 7.57 4.89 9.69 5.66 3.69 3.22 5.48

24 7.77 8.04 4.75 10.3 5.85 3.70 3.26 5.80

 

X 7.85 7.80 4.82 9.97 5.75 3.70 3.24 5.64

48 6.85 6.87 3.92 8.66 4.76 2.90 2.50 4.57

48 6.83 7.15 3.91 8.91 4.80 2.97 2.62 4.95

 

X 6.84 7.01 3.92 8.79 4.78 2.93 2.56 4.76

72 6.08 6.07 3.23 7.39 3.80 2.27 1.95 3.74

72 6.13 6.06 3.30 7.41 3.82 2.33 2.03 3.92

 

X 6.11 6.07 3.27 7.40 3.81 2.30 1.99 3.83

FEP lining in PE shell

1 11.5 8.74 11.2 12.1 10.6 9.91 8.05 7.32

1 11.2 8.94 11.1 12.3 10.8 10.3 8.48 7.89

 

X 11.3 8.84 11.2 12.2 10.7 10.1 8.27 7.61

8 11.3 8.45 10.9 11.0 9.70 8.59 6.39 5.31

8 11.3 8.02 10.9 10.4 9.31 8.31 6.13 4.95

 

X 11.3 8.24 10.9 10.7 9.51 8.45 6.26 5.13

24 11.0 7.07 10.6 8.79 8.57 7.34 4.92 3.47

24 11.3 6.91 10.8 8.46 8.39 7.17 4.70 3.27

 

X 11.2 6.99 10.7 8.62 8.48 7.26 4.81 3.37

48 11.1 5.48 10.6 6.62 7.17 6.02 3.64 2.31

48 11.2 5.67 10.7 6.83 7.35 6.16 3.73 2.39

 

X 11.1 5.58 10.7 6.73 7.26 6.09 3.68 2.35

72 10.7 4.03 10.1 4.87 5.68 4.73 2.67 1.57

72 10.7 4.28 10.2 5.13 5.90 4.92 2.80 1.68

 

X 10.7 4.16 10.1 5.00 5.79 4.82 2.73 1.63

FEP

1 11.3 9.32 11.2 12.7 10.9 10.1 8.20 7.74

1 11.4 9.19 11.2 12.5 10.8 9.95 8.00 7.37

 

X 11.4 9.25 11.2 12.6 10.9 10.0 8.10 7.56

8 11.3 8.54 10.8 10.8 9.49 8.19 5.97 4.96

8 10.9 7.89 10.5 10.1 8.96 7.88 5.81 4.66

 

X 11.1 8.21 10.7 10.5 9.22 8.03 5.89 4.81

24 11.1 6.69 10.6 8.04 7.96 6.61 4.19 2.92

24 11.1 6.69 10.6 8.09 8.02 6.62 4.20 2.88

 

X 11.1 6.69 10.6 8.07 7.99 6.61 4.20 2.90

48 10.9 5.55 10.3 6.34 6.74 5.44 3.20 2.09

48 10.9 5.45 10.4 6.33 6.82 5.50 3.21 2.06

 

X 10.9 5.50 10.3 6.33 6.78 5.47 3.21 2.07

72 10.7 4.40 9.95 4.89 5.53 4.41 2.44 1.50

72 10.6 4.36 9.96 4.87 5.50 4.43 2.47 1.54

 

X 10.6 4.38 9.96 4.88 5.52 4.42 2.45 1.52

21

Table A1 (cont’d).

Exposure time Analyte

(hr) NB TDCE MNT TCE CLB ODCB PDCB PCE
22

For each analyte and sampling time, values with the letter “a” are not significantly different from the

controls. For values marked with letters other than “a,” all values marked with the same letter are not

significantly different from each other. For example, there is no significant difference between the

concentration of nitrobenzene in samples exposed to either PVC or TPE for 1 hour (both marked “i”).

D—Concentration of analyte was below MDL.

Table A2. Mean concentrations (mg/L) of analytes used in the tubing material

study.

Exposure

time Analyte

(hr) NB TDCE MNT TCE CLB ODCB PDCB PCE

Controls

1 11.6 10.9 11.5 15.9 12.7 12.3 11.5 13.2

8 11.2 11.2 11.2 16.4 12.5 12.1 11.5 13.7

24 11.2 11.2 11.2 16.4 12.5 12.1 11.5 13.7

48 11.3 10.2 11.2 15.2 12.2 11.8 11.2 12.0

72 11.3 9.6 11.3 14.3 11.9 11.7 10.9 11.4

Polyurethane

1 0.827j 0.401m 0.487h,i 0.359l 0.242j 0.232j,k 0.188j 0.257i

8 0.301j 0.130k 0.053k 0.072l 0.032h 0.011g D 0.025h

24 0.237l 0.041m 0.031n 0.038m 0.018l 0.006k D 0.022i

48 0.236k D 0.022l 0.018i 0.013j D D 0.007h

72 0.162k D 0.019n 0.012j 0.007j 0.006h D 0.008g

PVC

1 1.25i 0.689l,m 0.402i 0.451l 0.255j 0.197k 0.164j 0.236i

8 0.917i 0.253j,k 0.085k 0.122l 0.053h 0.018g 0.015j 0.033h

24 1.10k 0.130l,m 0.053n 0.067m 0.031l 0.013j,k 0.014j 0.018i

48 1.26j 0.115k 0.037l 0.045i 0.023j 0.007i D 0.013h

72 0.816j 0.034k 0.030n 0.030j 0.017j 0.008h D 0.014g

TPE

1 1.72i 0.454m 0.640h,i 0.351l 0.239j 0.228j,k 0.188j 0.237i

8 0.549i,j 0.116k 0.141k 0.061l 0.034h 0.012g D 0.012h

24 0.374l 0.042m 0.079n 0.022m 0.016l 0.007j,k D 0.005i

48 0.252k 0.048k 0.060k,l 0.006i 0.006j D DD

72 0.144k D 0.062m,n 0.007j 0.009j D DD

Plasticized PP (formulation 2)

1 2.34h 0.553m 0.805h,i 0.356l 0.235j 0.193k 0.155j 0.192i

8 0.744i 0.168j,k 0.188k 0.084l 0.045h 0.014g 0.010j 0.012h

24 0.324l 0.048m 0.089n 0.045m 0.030l 0.010j,k 0.010j 0.007i

48 0.152k 0.004k 0.044l 0.010i 0.010j 0.006i D 0.006h

72 0.100k D 0.019n 0.019j 0.013j D DD

Plasticized PP (formulation 1)

1 2.43h 0.600m 0.846h 0.400l 0.264j 0.218k 0.177j 0.227i

8 0.849i 0.181j,k 0.219k 0.086l 0.049h 0.017g 0.010j 0.014h

24 0.426l 0.046m 0.114n 0.040m 0.028l 0.010j,k D 0.007i

48 0.206k 0.008k 0.064k,l 0.014i 0.013j 0.006i D 0.006h

72 0.098k D 0.034n 0.007j 0.010j D D 0.006g

Polyester lining in PVC shell

1 1.49i 1.07l 0.674h,i 0.778l 0.442j 0.304j,k 0.248j 0.411i

8 0.533i,j 0.517j,k 0.166k 0.246k,l 0.104h 0.031g 0.023i,j 0.066h

24 0.429l 0.329l 0.122n 0.164m 0.074l 0.026j,k 0.016j 0.041i

48 0.339k 0.229k 0.089k,l 0.114i 0.053j 0.029i 0.012f 0.028h

72 0.313j,k 0.160i,j,k 0.084l,m,n 0.085j 0.042j 0.025h 0.010j 0.026g

LDPE

1 8.52e 3.42j 4.92e,f 2.24k 1.35i 0.641i,j 0.440j 0.573i

8 6.26e 1.71i 2.64g 0.934j 0.507g,h 0.183g 0.115i,j 0.165h

24 4.73g 0.931k 1.67i 0.510l 0.294k 0.109i,j 0.067j 0.086i

48 3.83f 0.602j 1.22i 0.329i 0.195i,j 0.073i 0.044f 0.061g,h

72 2.95f 0.373i,j 0.902i,j 0.225j 0.139i,j 0.054h 0.031j 0.037g
XLPE

1 8.47e 3.42j 4.80f 2.24k 1.34i 0.609i,j 0.414j 0.552i

8 6.00e 1.70i 2.42g,h 0.910j,k 0.498h 0.177g 0.106i,j 0.160h

24 4.53g 0.928k 1.60i,j 0.508l 0.292k 0.108i,j,k 0.065j 0.090i

48 3.65f 0.584j 1.19i 0.327i 0.198i,j 0.076i 0.048f 0.059g,h

72 2.95f 0.390i 0.906i 0.235j 0.117i,j 0.056h 0.035j 0.041g

PE lining in an EVA shell

1 8.37e,f 3.11j,k 4.91e,f 2.16k 1.34i 0.683i 0.479j 0.610i

8 5.54f 0.832j 2.16h,i,j 0.557j,k,l 0.337h 0.139g 0.087i,j 0.107h

24 3.38i 0.340l 1.01l 0.221m 0.138l 0.062j,k 0.030j 0.054i

48 1.74i 0.177k 0.421j 0.110i 0.067j 0.035i 0.021f 0.038g,h

72 0.900i 0.090j,k 0.209l 0.070j 0.043j 0.022h 0.016j 0.026g

PE cross-linked to EVA shell

1 7.98f 2.95k 4.49f 2.07k 1.27i 0.607i,j 0.414j 0.554i

8 5.14f,g 0.786j,k 1.95i,j 0.528j,k,l 0.322h 0.142g 0.073i,j 0.133h

24 2.76j 0.327l 0.765m 0.196m 0.119l 0.055j,k 0.029j 0.051i

48 1.42j 0.183k 0.336j,k 0.109i 0.065j 0.027i 0.016f 0.031h

72 0.764i 0.102i,j,k 0.186l,m 0.072j 0.043j 0.019h 0.014j 0.023g

P(VDF-HFP)

1 8.03f 7.30f 4.76f 8.36g 5.31f 3.08f 2.51f 3.79f

8 5.31f,g 5.37f 2.28g,h,i 5.27f 2.73e 1.25f 1.00g 1.83e,f

24 3.96h 3.73g 1.48j 3.37h 1.77h 0.785g 0.614h 1.04f,g

48 3.09g 2.90f 1.07i 2.48f 1.27h 0.546g 0.426f 0.758d,e,f

72 2.32g 1.98f 0.778j,k 1.68g 0.889h 0.374g 0.285h 0.495e,

Fluoroelastomer

1 7.08g 6.73g,h 3.88g 7.23h 4.31g 2.42g 1.99g 2.95g

8 4.65h 5.00f 1.89j 4.51g 2.26e,f 1.04f 0.824g 1.45f

24 3.33i 3.21h 1.24k 2.78i 1.42i 0.641h 0.512h,i 0.790g

48 2.73h 2.46g 0.968i 2.08f 1.05h 0.478g,h 0.377f 0.580e,f,g

72 2.09g,h 1.70f 0.714k 1.41g 0.754h 0.331g 0.259h,i 0.390e,f

Polyamide*

1 7.99f 6.34h,i 5.30e 5.10j 3.14h 1.34h 1.02i 2.23h

8 4.99g,h 3.11h 2.29g,h,i 2.09i 1.11g 0.301g 0.247i 0.666g

24 3.27i 1.83j 1.31k 1.21k 0.744j 0.186i 0.155j 0.374h

48 2.50h 1.38i 0.990i 0.881h 0.517i 0.141h,i 0.118f 0.278f,g,h

72 1.95h 0.832h 0.747k 0.633i 0.275i 0.105h 0.087i,j 0.202f,g

PP

1 10.84c 6.07i 9.17c 5.81i 4.33g 2.39g 1.53h 1.73h

8 9.70c 3.90g 7.13e 3.03h 2.08f 0.944f 0.566h 0.665g

24 9.05e 2.60i 6.00g 1.90j 1.36i 0.615h 0.356i 0.388h

48 8.45d 1.81h 5.16g 1.30g 0.972h 0.458g,h 0.263f 0.283e,f,g,h

72 7.62d 1.40g 4.21g 1.00h 0.727h 0.338g 0.192h,i,j 0.211f,g

ETFE*

1 11.1b,

c 6.83g 10.3b 9.71f 8.43e 7.56e 5.38e 5.93d

8 9.96c 4.84f 8.62d 6.74e 5.76d 4.75e 2.86f 3.37d

24 9.24e 3.11h 7.42f 4.22g 3.88g 3.04f 1.56g 1.73e

48 8.56d 2.37g 6.44f 3.14e 2.88g 2.21f 1.09e 1.26d

72 7.64d 1.82f 5.32f 2.33f 2.13g 1.56f 0.737g 0.871d

PTFE*

1 11.6a 8.31e 11.2a 10.6e 9.62d 8.46d 6.15d 5.18e

8 10.7b 6.15e 9.69c 6.67e 6.14d 4.95e 3.04f 2.05e

24 10.6d 4.57f 9.77e 4.78f 5.21f 3.79e 2.01f 1.25f

48 10.5c 3.33e 9.30e 3.33e 3.91f 2.77e 1.38e 0.827d,e

72 10.3c 2.74e 8.90e 2.68e 3.21f 2.23e 1.09f 0.665d,e

For each analyte and sampling time, values with the letter “a” are not significantly different from the

controls. For values marked with letters other than “a,” all values marked with the same letter are not

significantly different from each other.

* Tubing had a different material surface-area-to-solution-volume ratio than other tubings.

Table A2 (cont’d).

Exposure

time Analyte

(hr) NB TDCE MNT TCE CLB ODCB PDCB PCE

23
PFA

1 11.5a,b 8.74d,e 11.2a 11.5d 10.2c 9.20c 6.95c 6.11d

8 11.2a 7.22d 10.7b 8.40d 7.96c 6.49d 3.94e 3.08d

24 10.9c 5.14e 10.2d 5.63e 6.01d 4.69d 2.57e 1.65e

48 10.9b 4.37d 10.0d 4.60d 5.20d 3.92d 2.03d 1.29d

72 10.6b 3.41d 9.43d 3.45d 4.05d 2.99d 1.48e 0.919d

PVDF

1 9.96d 9.64b 8.31d 13.6b 9.60d 7.77e 7.00c 9.86b

8 8.67d 9.23b 6.05f 12.4b 7.35c 5.13e 4.72d 8.22b

24 7.85f 7.80b 4.82h 9.97b 5.75e 3.70e 3.24d 5.64b

48 6.84e 7.01b 3.92h 8.79b 4.78e 2.93e 2.56c 4.76b

72 6.11e 6.07b 3.27h 7.40b 3.81e 2.30e 1.99d 3.83b

FEP lining in PE shell

1 11.3a,b 8.84c,d 11.2a 12.2c 10.7b 10.1b 8.27b 7.61c

8 11.3a 8.24c 10.9a,b 10.7c 9.51b 8.45b 6.26b 5.13c

24 11.2a,b 6.99c 10.7b 8.62c 8.48b 7.26b 4.81b 3.37c

48 11.1b 5.58c 10.7b 6.73c 7.26b 6.09b 3.68b 2.35c

72 10.7b 4.16c 10.1b 5.00c 5.79b 4.82b 2.73b 1.63c

FEP

1 11.4a,b 9.25b,c 11.2a 12.6c 10.9b 10.0b 8.10b 7.56c

8 11.1a,b 8.21c 10.7b 10.5c 9.22b 8.03c 5.89c 4.81c

24 11.1b,c 6.69d 10.6c 8.07d 7.99c 6.61c 4.20c 2.90d

48 10.9b 5.50c 10.3c 6.33c 6.78c 5.47c 3.21b 2.07c

72 10.6b 4.38c 9.96c 4.88c 5.52c 4.42c 2.45c 1.52c

For each analyte and sampling time, values with the letter “a” are not significantly different from

the controls. For values marked with letters other than “a,” all values marked with the same letter

are not significantly different from each other.

* Tubing had a different material surface-area-to-solution-volume ratio than other tubings.

Table A2 (cont’d). Mean concentrations (mg/L) of analytes used in the tubing material study.

Exposure

time Analyte

(hr) NB TDCE MNT TCE CLB ODCB PDCB PCE

24
25

Table A3. Means of normalized analyte concentrations for the tubing material study.1

Exposure time Analyte

(hr) NB TDCE MNT TCE CLB ODCB PDCB PCE

FLEXIBLE TUBINGS

Polyurethane

1 0.071 0.037 0.042 0.023 0.019 0.019 0.016 0.019

8 0.027 0.012 0.005 0.004 0.003 0.001 D 0.002

24 0.021 0.004 0.003 0.002 0.001 0.001 D 0.002

48 0.021 D 0.002 0.001 0.001 D D 0.001

72 0.014 D 0.002 0.001 0.001 0.001 D 0.001

PVC

1 0.108 0.063 0.035 0.028 0.020 0.016 0.014 0.018

8 0.082 0.023 0.008 0.007 0.004 0.001 0.001 0.002

24 0.098 0.012 0.005 0.004 0.003 0.001 0.001 0.001

48 0.112 0.011 0.003 0.003 0.002 0.001 D 0.001

72 0.073 0.004 0.003 0.002 0.001 0.001 D 0.001

TPE

1 0.149 0.042 0.056 0.022 0.019 0.019 0.016 0.018

8 0.049 0.010 0.013 0.004 0.003 0.001 D 0.001

24 0.033 0.004 0.007 0.001 0.001 0.001 D *

48 0.022 0.005 0.005 * 0.001 D D D

72 0.013 D 0.006 * 0.001 D D D

Plasticized PP (formulation 1)

1 0.210 0.055 0.074 0.025 0.021 0.018 0.015 0.017

8 0.076 0.016 0.020 0.005 0.004 0.001 0.001 0.001

24 0.038 0.004 0.010 0.002 0.002 0.001 D *

48 0.018 0.001 0.006 0.001 0.001 0.001 D *

72 0.009 D 0.003 0.001 0.001 D D 0.001

Plasticized PP (formulation 2)

1 0.202 0.051 0.070 0.022 0.018 0.016 0.013 0.015

8 0.066 0.015 0.017 0.005 0.004 0.001 0.001 0.001

24 0.029 0.004 0.008 0.003 0.002 0.001 0.001 0.001

48 0.013 * 0.004 0.001 0.001 * D *

72 0.009 D 0.002 0.001 0.001 D D D

P(VDF-HFP)

1 0.692 0.669 0.414 0.526 0.418 0.250 0.218 0.287

8 0.474 0.480 0.203 0.322 0.219 0.103 0.087 0.134

24 0.353 0.333 0.132 0.206 0.142 0.065 0.053 0.076

48 0.274 0.284 0.095 0.163 0.104 0.046 0.038 0.063

72 0.205 0.206 0.069 0.117 0.075 0.032 0.026 0.043

Fluoroelastomer

1 0.610 0.617 0.338 0.454 0.340 0.197 0.173 0.224

8 0.415 0.447 0.169 0.275 0.181 0.086 0.072 0.106

24 0.297 0.287 0.111 0.169 0.114 0.053 0.045 0.058

48 0.242 0.241 0.086 0.137 0.086 0.040 0.034 0.048

72 0.185 0.177 0.063 0.099 0.063 0.028 0.024 0.034

RIGID TUBINGS

Polyamide

1 0.688(.675) 0.581(.563) 0.461(.449) 0.320(.305) 0.247(.232) 0.109(.100) 0.089(.081) 0.169(.155)

8 0.446(.403) 0.278(.262) 0.204(.166) 0.127(.096) 0.089(.062) 0.025(.014) 0.021(.011) 0.049(.032)

24 0.292(.235) 0.163(.130) 0.117(.078) 0.074(.048) 0.059(.037) 0.015(.007) 0.013(.006) 0.027(.016)

48 0.221 0.135 0.088 0.058 0.042 0.012 0.011 0.023

72 0.173 0.087 0.066 0.044 0.024 0.009 0.008 0.018

1 These values are determined by dividing the mean concentration of a given analyte at a given time and for a particular tubing by the mean concentration (for the same analyte) of the control samples taken at the same time.

D–Analyte concentrations were less than MDL.

* Values less than 0.0005.

Values in parentheses are adjusted to a material surface-area-to-solution-volume ratio equivalent to the other tubing

materials.
26

PP

1 0.934 0.557 0.797 0.365 0.341 0.194 0.133 0.131

8 0.863 0.349 0.637 0.185 0.166 0.078 0.049 0.049

24 0.808 0.232 0.536 0.116 0.109 0.051 0.031 0.028

48 0.748 0.177 0.461 0.085 0.080 0.039 0.023 0.024

72 0.674 0.146 0.372 0.070 0.061 0.029 0.018 0.019

Polyester lining in PVC shell

1 0.129 0.098 0.059 0.049 0.035 0.025 0.022 0.031

8 0.048 0.046 0.015 0.015 0.008 0.003 0.002 0.005

24 0.038 0.029 0.011 0.010 0.006 0.002 0.001 0.003

48 0.030 0.022 0.008 0.007 0.004 0.002 0.001 0.002

72 0.028 0.017 0.007 0.006 0.004 0.002 0.001 0.002

LDPE

1 0.734 0.314 0.428 0.141 0.106 0.052 0.038 0.043

8 0.559 0.152 0.236 0.057 0.041 0.015 0.010 0.012

24 0.422 0.083 0.149 0.031 0.023 0.009 0.006 0.006

48 0.339 0.059 0.109 0.022 0.016 0.006 0.004 0.005

72 0.261 0.039 0.080 0.016 0.012 0.005 0.003 0.003

XLPE

1 0.730 0.314 0.418 0.141 0.106 0.050 0.036 0.042

8 0.536 0.151 0.216 0.055 0.040 0.015 0.009 0.012

24 0.405 0.083 0.143 0.031 0.023 0.009 0.006 0.007

48 0.323 0.057 0.107 0.022 0.016 0.006 0.004 0.005

72 0.261 0.041 0.080 0.016 0.010 0.005 0.003 0.004

PE lining in EVA shell

1 0.721 0.286 0.427 0.136 0.105 0.055 0.042 0.046

8 0.494 0.074 0.193 0.034 0.027 0.012 0.008 0.008

24 0.302 0.030 0.090 0.013 0.011 0.005 0.003 0.004

48 0.154 0.017 0.038 0.007 0.006 0.003 0.002 0.003

72 0.080 0.009 0.018 0.005 0.004 0.002 0.001 0.002

PE cross-linked to EVA shell

1 0.688 0.270 0.390 0.130 0.100 0.049 0.036 0.042

8 0.459 0.070 0.174 0.032 0.026 0.012 0.006 0.010

24 0.247 0.029 0.068 0.012 0.010 0.005 0.002 0.004

48 0.126 0.018 0.030 0.007 0.005 0.002 0.001 0.003

72 0.068 0.011 0.016 0.005 0.004 0.002 0.001 0.002

ETFE

1 0.956(.969) 0.626(.708) 0.895(.927) 0.611(.697) 0.664(.741) 0.615(.702) 0.468(.574) 0.449(.557)

8 0.889(.912) 0.432(.539) 0.770(.825) 0.411(.518) 0.461(.562) 0.393(.499) 0.248(.351) 0.246(.352)

24 0.825(.860) 0.278(.413) 0.662(.737) 0.257(.388) 0.310(.429) 0.252(.363) 0.136(.227) 0.126(.234)

48 0.758 0.233 0.575 0.207 0.236 0.187 0.097 0.105

72 0.676 0.189 0.471 0.163 0.179 0.133 0.068 0.076

PTFE

1 1.00(.985) 0.762(.723) 0.972(.969) 0.666(.626) 0.757(.726) 0.688(.655) 0.535(.496) 0.392(.345)

8 0.956(.944) 0.549(.480) 0.866(.890) 0.406(.354) 0.491(.475) 0.409(.371) 0.264(.211) 0.149(.111)

24 0.950(.921) 0.408(.381) 0.872(.848) 0.291(.252) 0.417(.368) 0.313(.263) 0.175(.131) 0.092(.066)

48 0.925 0.327 0.831 0.219 0.321 0.235 0.123 0.069

72 0.910 0.285 0.787 0.187 0.270 0.190 0.100 0.058

PFA

1 0.987 0.802 0.971 0.723 0.805 0.748 0.605 0.463

8 1.00 0.645 0.958 0.512 0.636 0.536 0.343 0.225

24 0.974 0.459 0.906 0.343 0.481 0.387 0.224 0.120

48 0.963 0.429 0.894 0.303 0.426 0.332 0.181 0.107

72 0.938 0.355 0.834 0.241 0.340 0.255 0.135 0.081

Table A3 (cont’d).

Exposure time Analyte

(hr) NB TDCE MNT TCE CLB ODCB PDCB PCE

Values in parentheses are adjusted to a material surface-area-to-solution-volume ratio equivalent to the other tubing

materials.
27

Table A3 (cont’d). Means of normalized analyte concentrations for the tubing material study.

Exposure time Analyte

(hr) NB TDCE MNT TCE CLB ODCB PDCB PCE

PVDF

1 0.858 0.885 0.722 0.854 0.756 0.632 0.609 0.747

8 0.774 0.824 0.540 0.756 0.588 0.424 0.410 0.600

24 0.701 0.696 0.430 0.608 0.460 0.305 0.282 0.412

48 0.605 0.687 0.350 0.578 0.392 0.249 0.229 0.397

72 0.540 0.632 0.289 0.517 0.320 0.196 0.183 0.336

FEP lining in PE shell

1 0.976 0.811 0.971 0.768 0.841 0.821 0.719 0.576

8 1.01 0.735 0.972 0.652 0.760 0.698 0.544 0.375

24 0.997 0.624 0.957 0.526 0.679 0.600 0.418 0.246

48 0.985 0.547 0.952 0.443 0.595 0.516 0.329 0.196

72 0.946 0.433 0.898 0.350 0.486 0.412 0.251 0.143

FEP

1 0.981 0.849 0.973 0.793 0.856 0.815 0.704 0.573

8 0.989 0.733 0.953 0.640 0.738 0.664 0.512 0.351

24 0.990 0.598 0.944 0.492 0.639 0.546 0.365 0.212

48 0.967 0.539 0.924 0.417 0.555 0.463 0.286 0.173

72 0.941 0.457 0.881 0.341 0.464 0.378 0.225 0.133
28

1-hr controls

11.5 10.8 11.0 13.4 11.1 11.2 11.5 13.4

11.3 10.6 10.9 13.1 10.9 10.9 11.2 12.8

11.9 10.5 11.4 13.0 11.0 11.1 11.3 12.8

11.5 10.6 11.1 13.2 11.1 11.2 11.5 13.1

11.3 10.3 10.9 12.8 10.7 10.8 11.1 12.4

11.3 10.2 11.0 12.8 10.8 10.9 11.2 12.7

PTFE

3.55 10.9 8.71 10.5 10.3 9.29 8.88 8.04 7.56

3.55 11.6 9.14 11.0 10.7 9.64 9.27 8.45 8.23

1.15 11.4 9.76 10.9 11.9 10.2 10.1 10.1 11.0

1.15 10.8 9.51 10.5 11.6 10.1 10.1 9.91 10.8

0.7 11.5 9.34 11.1 12.9 10.9 10.9 11.1 12.5

0.7 11.4 9.65 11.0 11.9 10.2 10.2 10.2 11.2

ETFE

2.15 11.6 9.97 11.1 12.4 10.5 10.4 10.3 11.6

2.15 11.5 9.81 11.0 12.1 10.3 10.1 9.8 11.3

0.74 11.3 10.3 10.9 12.8 10.7 10.7 10.9 12.6

0.74 11.2 10.1 10.9 12.7 10.7 10.8 10.9 12.4

0.45 11.2 10.3 10.9 12.9 10.9 11.0 11.1 12.8

0.45 11.4 10.1 11.0 12.6 10.7 10.8 10.9 12.2

Polyamide

3.59 9.70 8.35 8.09 8.23 6.25 4.70 4.50 6.36

3.59 9.52 8.21 7.68 7.64 5.62 3.76 3.47 5.55

1.14 10.79 9.10 9.64 9.96 8.12 7.11 6.97 8.70

1.14 10.8 9.81 10.0 11.3 9.23 8.52 8.54 10.3

0.69 11.6 10.3 10.6 11.9 9.78 9.06 9.09 10.8

0.69 11.0 9.82 10.3 11.6 9.59 9.15 9.24 11.1

8-hr controls

11.6 12.1 11.2 15.2 12.4 12.2 12.6 14.8

11.7 12.1 11.2 15.1 12.3 12.1 12.5 14.5

12.0 12.4 11.5 15.4 12.6 12.3 12.8 15.3

12.1 12.0 11.5 15.0 12.2 12.0 12.5 14.5

12.1 12.1 11.5 14.9 12.2 12.0 12.5 14.5

12.2 12.1 11.6 14.9 12.3 12.2 12.6 14.8

PTFE

3.55 11.5 7.87 10.7 8.32 8.17 7.05 5.24 4.07

3.55 11.2 8.20 10.5 8.71 8.38 7.20 5.43 4.54

1.15 11.8 11.0 11.3 12.8 11.1 10.4 9.51 9.67

1.15 11.6 10.6 11.1 12.5 10.9 10.2 9.40 9.39

0.7 11.4 10.3 11.0 12.5 10.7 10.3 9.89 10.5

0.7 11.3 10.4 10.9 12.7 10.9 10.5 10.1 10.5

Surface-areato-solutionvolume ratio Analyte

(cm–1) NB TDCE MNT TCE CLB ODCB PDCB PCE

Surface-areato-solutionvolume ratio Analyte

(cm–1) NB TDCE MNT TCE CLB ODCB PDCB PCE

ETFE

2.15 11.3 10.0 10.6 12.5 10.4 9.71 8.89 10.7

2.15 11.5 10.3 10.8 12.8 10.7 9.87 8.91 11.0

0.74 11.9 11.6 11.3 14.3 11.8 11.4 11.3 13.6

0.74 11.7 11.2 11.2 13.9 11.5 11.1 11.0 13.0

0.45 11.4 10.9 11.0 13.6 11.2 11.0 11.0 13.0

0.45 11.8 11.2 11.2 13.9 11.5 11.3 11.3 13.1

Polyamide

3.59 6.94 6.74 3.94 3.78 2.21 0.738 0.666 1.69

3.59 6.97 6.49 3.97 3.71 2.24 0.823 0.751 1.72

1.14 10.3 10.1 8.03 9.02 6.20 3.21 2.93 5.79

1.14 9.73 9.51 7.62 8.45 5.75 2.87 2.62 5.20

0.69 10.8 10.2 8.98 10.2 7.41 4.69 4.46 7.25

0.69 10.9 10.9 9.11 10.8 7.88 5.04 4.77 7.90

24-hr controls

12.0 11.6 11.4 14.4 11.5 11.3 11.6 14.7

11.4 11.2 11.1 14.0 11.2 11.0 11.3 14.6

11.5 11.4 11.1 14.2 11.3 11.2 11.6 15.0

11.3 11.5 10.9 14.3 11.3 11.3 11.8 15.6

11.6 11.1 11.2 13.7 11.0 10.8 11.1 14.4

11.8 10.8 11.3 13.4 10.8 10.8 11.1 13.7

PTFE

3.55 10.8 6.19 10.0 6.19 6.41 5.33 3.56 2.71

3.55 11.2 6.86 10.3 6.73 6.73 5.47 3.65 3.05

1.15 11.9 10.2 11.1 11.3 9.82 8.85 7.52 7.76

1.15 11.0 9.24 10.6 10.5 9.17 8.39 7.14 7.19

0.7 11.2 9.61 10.8 11.2 9.53 9.05 8.16 8.89

0.7 11.7 9.64 11.1 11.2 9.59 9.10 8.30 8.95

ETFE

2.15 11.1 8.88 10.3 11.0 9.10 8.29 7.09 9.47

2.15 11.0 8.74 10.1 10.8 8.85 7.97 6.65 9.21

0.74 11.5 10.7 10.9 13.2 10.5 10.0 9.50 12.9

0.74 11.4 10.2 10.8 12.6 10.2 9.64 9.13 11.9

0.45 11.8 10.6 11.1 13.0 10.4 10.0 9.78 12.7

0.45 11.8 10.5 11.2 12.8 10.4 10.1 9.76 12.7

Polyamide

3.59 4.57 2.88 1.94 1.68 0.976 0.288 0.269 0.710

3.59 4.89 3.18 2.14 1.84 1.05 0.293 0.263 0.777

1.14 8.41 8.03 5.91 6.04 3.72 1.48 1.33 3.46

1.14 8.94 8.46 6.11 6.22 3.80 1.47 1.32 3.49

0.69 9.72 8.72 7.31 7.41 4.82 2.16 1.95 4.54

0.69 9.67 8.42 7.17 6.96 4.50 1.93 1.71 4.15

Table A4. Concentrations (mg/L) of analytes in surface-area-to-solution-volume study.
29

1-hour

PTFE

5.30* 1.014 0.790 0.989 0.695 0.780 0.712 0.561 0.421

5.30* 0.990 0.729 0.964 0.636 0.729 0.662 0.507 0.361

3.55 0.958 0.815 0.955 0.776 0.841 0.803 0.707 0.576

3.55 1.019 0.855 1.007 0.807 0.873 0.838 0.744 0.628

1.15 0.977 0.922 0.972 0.911 0.923 0.907 0.887 0.853

1.15 0.922 0.899 0.936 0.889 0.914 0.905 0.870 0.832

0.70 1.022 0.911 1.017 1.007 1.013 1.008 0.994 0.994

0.70 1.015 0.941 1.007 0.935 0.948 0.940 0.922 0.889

ETFE

8.40* 0.966 0.611 0.908 0.598 0.654 0.614 0.470 0.443

8.40* 0.945 0.637 0.888 0.622 0.669 0.614 0.464 0.453

2.15 1.015 0.933 1.009 0.934 0.954 0.944 0.904 0.883

2.15 1.012 0.918 1.003 0.911 0.928 0.915 0.866 0.865

0.74 0.964 0.971 0.969 0.974 0.969 0.962 0.955 0.977

0.74 0.955 0.954 0.966 0.966 0.969 0.972 0.958 0.961

0.45 0.991 1.006 1.001 1.009 1.013 1.011 1.001 1.015

0.45 1.016 0.984 1.011 0.984 0.991 0.993 0.984 0.973

Polyamide

5.60* 0.642 0.574 0.408 0.296 0.220 0.093 0.080 0.152

5.60* 0.735 0.585 0.518 0.344 0.273 0.124 0.097 0.185

3.59 0.852 0.782 0.738 0.622 0.566 0.425 0.396 0.485

3.59 0.836 0.768 0.700 0.578 0.508 0.340 0.306 0.423

1.14 0.923 0.860 0.858 0.760 0.736 0.638 0.611 0.672

1.14 0.923 0.927 0.890 0.864 0.837 0.765 0.749 0.799

0.69 1.029 1.001 0.973 0.934 0.909 0.835 0.818 0.861

0.69 0.972 0.958 0.947 0.911 0.892 0.843 0.832 0.881

8-hour

PTFE

5.30* 0.931 0.534 0.888 0.412 0.522 0.423 0.268 0.156

5.30* 0.956 0.533 0.906 0.413 0.531 0.428 0.264 0.155

3.55 0.987 0.651 0.952 0.549 0.660 0.581 0.417 0.277

3.55 0.958 0.677 0.938 0.575 0.677 0.593 0.432 0.309

1.15 0.980 0.898 0.978 0.845 0.899 0.855 0.752 0.651

1.15 0.961 0.865 0.964 0.825 0.878 0.840 0.744 0.632

0.70 0.937 0.852 0.950 0.836 0.870 0.852 0.790 0.714

0.70 0.931 0.862 0.943 0.849 0.885 0.865 0.805 0.717

ETFE

8.40* 0.877 0.417 0.766 0.397 0.454 0.393 0.251 0.234

8.40* 0.894 0.450 0.776 0.427 0.467 0.395 0.245 0.257

2.15 0.969 0.828 0.947 0.824 0.842 0.800 0.707 0.727

2.15 0.990 0.854 0.962 0.842 0.861 0.813 0.709 0.748

0.74 0.988 0.947 0.981 0.941 0.954 0.940 0.896 0.914

0.74 0.973 0.918 0.970 0.919 0.931 0.917 0.871 0.878

0.45 0.940 0.897 0.951 0.913 0.916 0.908 0.882 0.885

0.45 0.974 0.925 0.972 0.928 0.940 0.931 0.900 0.893

Polyamide

5.60* 0.449 0.286 0.208 0.131 0.091 0.025 0.022 0.050

5.60* 0.439 0.271 0.201 0.124 0.087 0.024 0.021 0.047

3.59 0.596 0.557 0.351 0.250 0.179 0.061 0.053 0.115

3.59 0.599 0.536 0.354 0.245 0.181 0.068 0.060 0.117

1.14 0.853 0.826 0.697 0.594 0.501 0.265 0.232 0.389

1.14 0.806 0.777 0.662 0.557 0.465 0.236 0.207 0.350

0.69 0.892 0.846 0.777 0.682 0.604 0.388 0.356 0.494

0.69 0.896 0.898 0.788 0.724 0.643 0.416 0.381 0.538

Table A5. Normalized concentrations of analytes in surfacearea-to-solution-volume study.

Surface-area-

 to-solutionvolume ratio

 (cm–1) NB TDCE MNT TCE CLB ODCB PDCB PCE

* Values from initial study.
30

24-hour

PTFE

5.30* 0.933 0.437 0.867 0.309 0.420 0.315 0.177 0.102

5.30* 0.948 0.456 0.878 0.321 0.433 0.324 0.183 0.107

3.55 0.923 0.543 0.894 0.436 0.566 0.478 0.311 0.185

3.55 0.957 0.602 0.918 0.474 0.594 0.490 0.318 0.208

1.15 1.045 0.894 1.010 0.795 0.870 0.788 0.643 0.507

1.15 0.963 0.807 0.957 0.738 0.813 0.747 0.611 0.470

0.70 0.958 0.876 0.961 0.827 0.876 0.838 0.737 0.633

0.70 0.999 0.879 0.985 0.828 0.881 0.843 0.749 0.637

ETFE

8.40* 0.817 0.310 0.663 0.283 0.320 0.259 0.143 0.148

8.40* 0.815 0.297 0.661 0.273 0.315 0.255 0.137 0.139

2.15 0.949 0.779 0.922 0.776 0.803 0.743 0.619 0.645

2.15 0.938 0.766 0.902 0.759 0.781 0.714 0.581 0.628

0.74 1.008 0.935 0.984 0.924 0.934 0.891 0.813 0.843

0.74 1.002 0.893 0.976 0.887 0.900 0.858 0.781 0.777

0.45 1.004 0.966 0.987 0.960 0.958 0.929 0.882 0.906

0.45 1.009 0.954 0.997 0.944 0.952 0.935 0.880 0.907

Polyamide

5.60* 0.283 0.174 0.116 0.079 0.060 0.016 0.014 0.031

5.60* 0.294 0.183 0.119 0.081 0.062 0.016 0.014 0.031

3.59 0.390 0.252 0.173 0.119 0.086 0.026 0.024 0.048

3.59 0.418 0.279 0.190 0.130 0.092 0.026 0.023 0.053

1.14 0.738 0.701 0.535 0.424 0.329 0.131 0.113 0.226

1.14 0.784 0.739 0.553 0.437 0.337 0.131 0.113 0.228

0.69 0.828 0.795 0.652 0.548 0.443 0.200 0.176 0.323

0.69 0.824 0.767 0.639 0.514 0.413 0.179 0.154 0.296

Table A5 (cont’d). Normalized concentrations of analytes in

surface-area-to-solution-volume study.

Surface-area-

 to-solutionvolume ratio

 (cm–1) NB TDCE MNT TCE CLB ODCB PDCB PCE

* Values from initial study.
31

APPENDIX B: ANALYTE LOSSES

Table B1. An example of the calculations used to determine the losses of analytes after 5 and 10

minutes.

For this example:

Time = 10 minutes

Analyte lost = PCE

Sorptive Material = PVC

1. Determination of the percent sorbed after 10 minutes vs 60 minutes based on the data of

Barcelona et al. (1985).

Analyte sorbed* (μg/m2)

after after Percent

Analyte Material 10 min. 60 min. sorbed

TCE SIL 125 165 76

PVC 120 160 75

Chloroform SIL 120 160 75

PVC 95 145 66

PCE SIL 120 150 80

PVC 125 165 76

Trichloro- SIL 110 143 77

ethane PVC 90 140 64

x = 74%†

* These values are taken from Figure 2 in Barcelona et al.

(1985).

† Rounding to nearest 5% = 75%.

SIL = Silicone rubber tubing.

2. Amount of PCE sorbed by PVC after 60 minutes in our study = 1 – (mean normalized concentration of PCE in solution) = 1 – 0.018= 0.982.

3. (#1) (#2) = (75%) (0.982) = 74% of the PCE in solution would be sorbed by PVC after 10 minutes’

contact.
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 February 1996 (rev. October 1996)

Sampling Trace-Level Organics with Polymeric Tubings

Louise V. Parker and Thomas A. Ranney

U.S. Army Cold Regions Research and Engineering Laboratory

72 Lyme Road Special Report 96-3

Hanover, New Hampshire 03755-1290

U.S. Army Environmental Center

Aberdeen Proving Ground, Maryland SFIM-AEC-ET-CR-95072

Approved for public release; distribution is unlimited.

Available from NTIS, Springfield, Virginia 22161.

37

UNCLASSIFIED UNCLASSIFIED UNCLASSIFIED UL

There is concern whether tubings used to sample groundwater can affect contaminant concentrations. Tubings

might sorb contaminants, thereby giving falsely low values, or they might leach contaminants, thereby giving

falsely high values. There also is concern that a tubing used previously in a well with high concentrations of

contaminants might subsequently desorb contaminants into samples taken from other wells if decontamination is insufficient. Our review of the literature indicated that these concerns are valid, although a comprehensive study of this subject does not exist. In our laboratory study, we looked for sorption of a suite of organic

solutes by 20 polymeric tubings under static conditions. Seven of these tubings were flexible and the others

were rigid. We found that among the rigid tubings tested, the three fluoropolymers (fluorinated ethylene propylene [FEP], FEP-lined polyethylene, and polyvinylidene fluoride [PVDF]) were the least sorptive tubings.

However, even these tubings readily sorbed some of the analytes. Among the flexible tubings tested, a fluoroelastomer tubing and a tubing made of a copolymer of vinylidene fluoride and hexafluoropropylene

(P[VDF-HFP]) were the least sorptive. We also found that several of the 20 tubings appeared to leach constituents into the test solution. We were unable to detect any evidence that constituents leached from the polyethylene tubings, the rigid fluoropolymer tubings, and one of the plasticized polypropylene tubings. Currently,

we are conducting studies to see whether the effects we observed in this study increase, decrease, or remain

the same under dynamic conditions.

see reverse
Ethylene tetrafluoroethylene

Fluorinated ethylene-propylene

Hexafluoropropylene

Perfluoroalkoxy

Polyamide

Polyester

Polyethylene

Polymeric tubing

Polypropylene

Polytetrafluoroethylene

Polyurethane

Polyvinyl chloride

Polyvinylidene fluoride

Sampling tubing

Thermoelastic elastomer

Tubing

14. SUBJECT TERMS