Time-weighted average sampling of airborne propylene glycol ethers by a solid-phase microextraction device.

Time-weighted average sampling of airborne propylene glycol ethers by a solid-phase microextraction device.

Journal of occupational and environmental hygiene (2012-06-02)

H C Shih, S W Tsai, C H Kuo

ABSTRACT

A solid-phase microextraction (SPME) device was used as a diffusive sampler for airborne propylene glycol ethers (PGEs), including propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), and dipropylene glycol monomethyl ether (DPGME). Carboxen-polydimethylsiloxane (CAR/PDMS) SPME fiber was selected for this study. A polytetrafluoroethylene (PTFE) tubing was used as the holder, and the SPME fiber assembly was inserted into the tubing as a diffusive sampler. The diffusion path length and area of the sampler were 0.3 cm and 0.00086 cm(2), respectively. The theoretical sampling constants at 30°C and 1 atm for PGME, PGMEA, and DPGME were 1.50 × 10(-2), 1.23 × 10(-2) and 1.14 × 10(-2) cm(3) min(-1), respectively. For evaluations, known concentrations of PGEs around the threshold limit values/time-weighted average with specific relative humidities (10% and 80%) were generated both by the air bag method and the dynamic generation system, while 15, 30, 60, 120, and 240 min were selected as the time periods for vapor exposures. Comparisons of the SPME diffusive sampling method to Occupational Safety and Health Administration (OSHA) organic Method 99 were performed side-by-side in an exposure chamber at 30°C for PGME. A gas chromatography/flame ionization detector (GC/FID) was used for sample analysis. The experimental sampling constants of the sampler at 30°C were (6.93 ± 0.12) × 10(-1), (4.72 ± 0.03) × 10(-1), and (3.29 ± 0.20) × 10(-1) cm(3) min(-1) for PGME, PGMEA, and DPGME, respectively. The adsorption of chemicals on the stainless steel needle of the SPME fiber was suspected to be one of the reasons why significant differences between theoretical and experimental sampling rates were observed. Correlations between the results for PGME from both SPME device and OSHA organic Method 99 were linear (r = 0.9984) and consistent (slope = 0.97 ± 0.03). Face velocity (0-0.18 m/s) also proved to have no effects on the sampler. However, the effects of temperature and humidity have been observed. Therefore, adjustments of experimental sampling constants at different environmental conditions will be necessary.

MATERIALS

Product Number

Brand

Product Description

57906-U

Supelco

SPME fiber assembly Carboxen/Polydimethylsiloxane (CAR/PDMS), d_f 85 μm(CAR/PDMS, for use with autosampler, needle size 23 ga, metal alloy fiber

57912-U

Supelco

SPME fiber assembly Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), for use with autosampler, needle size 23 ga, metal alloy fiber, fiber L 1 cm

11048-U

Supelco

Carboxen^® Adsorbent, matrix Carboxen^® 569, 20-45 mesh, bottle of 500 g

283282

Sigma-Aldrich

Di(propylene glycol) methyl ether, mixture of isomers, 97%

57328-U

Supelco

SPME fiber assembly Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), needle size 24 ga, for use with manual holder

484253

Sigma-Aldrich

Di(propylene glycol) methyl ether, mixture of isomers, ≥99%

57329-U

Supelco

SPME fiber assembly Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), needle size 24 ga, StableFlex, for use with autosampler

10477-U

Supelco

Carboxen^® Adsorbent, matrix Carboxen^® 1000, 40-60 mesh, bottle of 50 g

57318

Supelco

SPME fiber assembly Carboxen/Polydimethylsiloxane (CAR/PDMS), d_f 75 μm(CAR/PDMS, for use with manual holder, needle size 24 ga

57319

Supelco

SPME fiber assembly Carboxen/Polydimethylsiloxane (CAR/PDMS), d_f 75 μm(CAR/PDMS, needle size 24 ga, for use with autosampler

10263

Supelco

Carboxen^® Adsorbent, matrix Carboxen^® 563, 20-45 mesh, bottle of 10 g

10264

Supelco

Carboxen^® Adsorbent, matrix Carboxen^® 564, 20-45 mesh, bottle of 10 g

10269

Supelco

Carboxen^® Adsorbent, matrix Carboxen^® 569, 20-45 mesh, bottle of 10 g

25467

Supelco

Carboxen^®-1010 PLOT Capillary GC Column, L × I.D. 30 m × 0.53 mm, average thickness 30 μm

10471

Supelco

Carboxen^® Adsorbent, matrix Carboxen^® 1003, 40-60 mesh, bottle of 10 g

25461

Supelco

Carboxen^®-1006 PLOT Capillary GC Column, L × I.D. 30 m × 0.53 mm, average thickness 30 μm

11324-U

Supelco

Carboxen^® Adsorbent, matrix Carboxen^® 564, 20-45 mesh, pack of 144 × 290 mg

24246

Supelco

Carboxen^®-1010 PLOT Capillary GC Column, L × I.D. 30 m × 0.32 mm, average thickness 15 μm

65692

Supelco

1-Methoxy-2-propanol, analytical standard

484407

Sigma-Aldrich

1-Methoxy-2-propanol, ≥99.5%

24241-U

Supelco

Carboxen^®-1006 PLOT Capillary GC Column, L × I.D. 30 m × 0.32 mm, average thickness 15 μm

57335-U

Supelco

SPME fiber assembly Carboxen/Polydimethylsiloxane (CAR/PDMS), d_f 85 μm(CAR/PDMS, needle size 24 ga, StableFlex, for use with autosampler

57343-U

Supelco

SPME fiber assembly Carboxen/Polydimethylsiloxane (CAR/PDMS), d_f 75 μm(CAR/PDMS, needle size 23 ga, for use with autosampler

54041-U

Supelco

Carboxen^® 1000 Reversible SPE Tube, 200 mg/mL, pk 30

57298-U

Supelco

SPME fiber assembly Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), needle size 23 ga, StableFlex, for use with autosampler

57295-U

Supelco

SPME fiber assembly Carboxen/Polydimethylsiloxane (CAR/PDMS), d_f 85 μm(CAR/PDMS, needle size 23 ga, StableFlex, for use with autosampler

57344-U

Supelco

SPME fiber assembly Carboxen/Polydimethylsiloxane (CAR/PDMS), d_f 75 μm(CAR/PDMS, needle size 23 ga, for use with manual holder

57914-U

Supelco

SPME fiber assembly Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), for use with autosampler, needle size 23 ga, metal alloy fiber, fiber L 2 cm

57334-U

Supelco

SPME fiber assembly Carboxen/Polydimethylsiloxane (CAR/PDMS), d_f 85 μm(CAR/PDMS, needle size 24 ga, for use with manual holder, StableFlex fiber

10478-U

Supelco

Carboxen^® Adsorbent, matrix Carboxen^® 1000, 60-80 mesh, bottle of 10 g