Gas Chromatographic Analysis of Phthalate Esters in Plastic Toys

S. C. Rastogi

National Environmental Research Institute, Department of Environemntal Chemistry, EO.Box 358, 4000 Roskilde, Denmark

Key Words Gas chromatography Phthalate esters PVC Plastic toys

Summary A method for the analysis of 10 phthalate esters in plas- tic toys is described. The samples are soxhlet extracted in dichloromethane and phthalate esters in the extract are analysed by GC. Detection limits of dimethyl phtha- late, diethyl phthalate, dibutyl phthalate, bis(2-ethyl- hexyl) phthalate, di-n-octyl phthalate, di-n-nonyl phtha- late, benzyl butyl phthalate and benzyl octyl phthalate were approximately 5 ppm. The detection limits of dii- sononyl phthalate and diisodecyl phthalate, which are mixtures of several isomers, were approximately 200ppm. Analysis of 17 plastic toys revealed that only PVC-toys contained phthalate esters. Bis(2-ethylhexyl) phthalate, diisononyl phthalate and diisodecyl phthalate in concentrations up to 40 % were present in the PVC- toys.

Introduction Phthalate esters are used as plasticizers in polymeric materials such as polyvinyl chloride (PVC) used for the production of consumer products and building materi- als. On the basis of data on consumption of phthalate es- ters in Europe, bis(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), diisodoceyl phthalate (DIDP), butyl benzyl phthalate (BBP), dibutyl phtha- late (DBP), diisobutyl phthalate (DIBP), ditridecyl phthalate (DTDP), diethyl phthalate (DEP) and di- methyl phthalate (DMP) are the most commonly used phthaltes [1]. Some of these phthalates have been impli-

cated with prenatal and developmental toxicity, estrogenic effect and in induction of asthama [1-6]. Phthalates are not chemically bound to the polymeric material and, therefore, they can leach out to the sur- rounding environment. Infants have a tendency of mouthing all toys they get. Thus, leaching of phthalates from toys into saliva is a route of intake of phthalate es- ters by children. The use of phthalate ester plasticizer in PVC-toys has, therefore, become an issue of serious health concern. In the present communication, a method for the extraction and gas chromatographic (GC) analysis of 10 commonly used phthalates, includ- ing those of health concern in toys, is described.

Experimental Samples

Seven PVC-toys (4 teethers and 3 dolls) and 10 non- PVC plastic toys were analysed for the content of phtha- lates.

Phthalate Esters

DMP was obtained from BDH (England), DEHP and DEP were from Aldrich (Germany), BBP and DBP were from E. Merck (Germany), DINP and DIDP were from Fluka (Switzerland), di-n-octyl phthalate (DNOP) and di-n-nonyl phthalate (DNNP) were were from TCI (Japan) and butyl octyl phthalate (BOP) was from Chem Service (PA, USA).

Extraction of Phthalate Esters and Analysis

Approximately 1 g sample in 100 mL dichloromethane was soxhlet extracted for 16 hours at 60 ~ Using a rota- tory evaporator at 30 ~ 90 mL of the extract was con- centrated under vacuum to 10 mL. The unconcentrated extract as well as the concentrated extract of each sam- ple were analysed by GC under following condtions:

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Chromatographia Vol.47, No.784, 1998 Short Communication

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Instrument:

GC-Column:

Temperature program:

Carrier Gas:

Injector:

Detector:

Hewlett Packard (HP) gas chromatograph 5890A with split/splitless injector and fla- me ionisation detector, HP autosampler 7673A and HP Chemstation

Chrompack fused silica co- lumn CP-Sil-5CB, 50 m x 0.32 mm (i.d.), df 0.12 jam

Start temperature 150 ~ 5 ~ rain -~ to 280 ~ 5 min at 280 ~

He, 55 mL min-', column head pressure 19.5 pSi

Split, 300 ~ injection volume 1 pL.

Flame ionisation, 300 ~

Phthalate standards dissolved in dichloromethane (0.1% (w/v) for DINP and DIDP and 0.01% (w/v) for other phthalates) were analysed by GC under the condi- tions as the samples. Identification of phthalates was performed by comparing the retention time (tR) of the samples GC-peaks with the t R of the phthalate stan- dards. The sample extracts spiked with appropriate amounts of standard phthalates were also analysed for the confirmation of the identification of phthalate es- ters. Calibration curves for DINP and DIDP were pre- pared in the concentration range 0.05 %-0.80 %, and for other phthalates in the concentration range 0.002-0.2 %.

Results and Discussion

The phthalate esters in the sample extracts were identi- fied by their respective GC-t R as well as by co-elution of standard phthalate esters, which were added to sample extracts prior to GC analysis. Relative standard devia- tion of t R of phthalates was below 0.5 %. As none of the investigated samples were found to contain BOP, this ester can be used as an internal standard for the identifi- cation of phthalates by comparing relative retention times. However, in doubtful cases, GC-mass spectro- metric analysis may be required for the identification of phthalate esters. DINP and DIDP, which are mixtures of several isomers, can be identified only on the basis of their chromatographic pattern and t R of their respective isomers (Figure 1). The GC-peaks of late eluting iso- mers of DINP overlapped with early eluting GC-peaks of DIDP isomers. However, identification of these two substances present in a sample was not a problem, be- cause the chromatographic pattern of isomeric peaks of DINP covered t R 22.0-25.7 min in the chromato- gram compared to DIDP isomers which have t R 25.2-26.9 min. The GC-peak of DNOP (t R 23.17 min) was found to overlap one of the GC-peaks of DINP iso- mers (Figure 1). As this isomer was present in very samll amounts DINP standard substance, a significant amount of DNOP (> 1%) can easily be identified when that was present together with 5 % DINP in a sample. Detection limits of all of the phthalates investigated in the present study, except DINP and DIDP, were ap- proximately 5 ppm. The detection limits of DINP and DIDP were approximately 200 ppm.

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Figure 1 GC analysis of approximately 120 ppm of each of DMP' DEP, DBP' BBP' BOP, DEHP, DNNP, DNOP. DINP (1080 ppm ) and DIDP (970 ppm) being mixtures of several isomers were analysed separately under the same conditions as the mixture of other phthalates, tR DINP: 22.942-25.662 min, tR DIDP: 25.289-26.956 min.

Short Communication Chromatographia Voi.47, No.784, 1998 725

Table I: Phthalate esters and their contents in the products investigation*.

Product Part investigated Phthalate content %, w/w

DINP + DIDP** DEHP DBP DEP BBP

Teether Part to be mouthed 32.4 0.01 n.d. n.d. n.d. Teether Part to be mouthed 38.9 + 10.1 n.d. n.d. 0.13 n.d. Teether Part to be mouthed 40.2 + 7.9 0.07 n.d. n.d. n.d. Teether Part to be mouthed 31.6 + 0.7 0.04 n.d. n.d. n.d. Doll Arm 19.6 n.d. n.d. n.d. n.d. Doll Head n.d. 22.40 0.01 n.d. 0.02 Doll Head 26.5 + 2.1 0.12 n.d. n.d. n.d.

* 10 non-PVC toys did not contain any of the phthalates investigated. ** DIDP and DINP are reported together, because of overlap of peaks of these esters. N.d.: not detected.

The content of phthala tes in toys was determined by ex- ternal s tandard me thod using calibration curves of re- spective esters. The calibration curves for all of the phthala te esters were l inear in the investigated concen- t ra t ion range, coefficient of correlat ion > 0.9989. The re- covery of the s tandard phtha la te esters, added to extract ion medium, by soxhlet extraction were 85-93 %, and the relative s tandard deviat ion of quanti tat ive analysis of the phthalates was below 6 %. All of the GC-peaks of isomeric D I N P and D I D P were taken into account for the calculation of their content in toy mate- rials.

The phthalates identified and their contents in the in- vest igated products are described in Table I. D I N P and D I D P contents are repor ted together, because of over- lap of isomeric peaks of these substances. The early eluting peaks of D I D P (t R 25.2-25.7 rain) were consid- e red as DINP. The results are not corrected for the re- covery. As it was not possible to obtain a PVC sample with known concentrat ions of phthalates , extraction ef- ficiency of phthalates f rom PVC could not be evaluated. Soxhlet extract ion of a non -PVC sample (without phthala te content) together with D E H P , D I N P and D I D P added to the extract ion medium, revealed that re- coveries of these esters were similar to those obtained without any sample (see above) . Use of another extrac- tion solvent, i.e. n-hexane, revealed no significant differ- ence in D I N P / D I D P contents of 4 samples (2 dolls and

2 teethers): the amounts extracted varied within • 4 %. However , the D E H P extracted f rom the samples by di- chloromethane was > 10 % higher compared to that by n-hexane.

Acknowledgements Mrs. I. M. WorsOe provided technical assistance. Danish Envi ronmenta l Protect ion Agency provided the sam- ples for investigation.

References [1] C A. Harris, P. Henttu, M.G. Parker, J. P. Stumper, Environ.

Health Perspect. 105, 802 (1997). [2] E.J.. Ritter, IV.. J. Scott, J. L. Randall, J. M. Ritter, Teratology 35,

41 (1987). [3] M.G. Narotsky, R. J. Kavlock, J. Toxicol. Environ. Health 45,

145 (1995). [4] K. Shito, S. Mima, Arch. of Toxicol. 56, 263 (1985). [5] J. Hellwig, H. Freudenberer, R. Jiickh,Food Chem.Toxicol. 35,

501(1997). [6] L. Oie, L.-G. Hersoug, J. O. Madsen, Environ. Health Per-

spect. 105, 972 (1997).

Received: Jan 22, 1998 Revised manuscript received: Mar 2,1998 Accepted: Apr 6,1998

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