Detection Of Perfluorooctane Sulfonate (PFOS) In Textile Samples By In-Port Derivatization/Gas Chromatography/Mass Spectrometry

As one of the most important chemical substances in the last century, perfluorooctane sulfonate (PFOS) is widely applied in different areas and fields owing to its highly stable and outstanding water-resistant and oil-resistant. At the beginning of 21st century, PFOS is regarded as a kind of newly found and persistent organic pollutants (POPs) due to its persistence and biological toxicity, which should be given focus in terms of study and prevention. It is urgent to establish appropriate test method and compile corresponding laws and regulations. As a large textile country, it is quite pressing to develop the test method of PFOS in textile products so as to improve the domestic product quality textiles, protect the human health and the environment and respond actively to the trade barrier of technique.PFOS is difficult to be separated and characterized by conventional techniques. In this paper, the methods of the extraction and derivatization of PFOS in textiles were studied. A novel detecting method of trace analysis for the residual content of PFOS in textiles, which were finished by oil, water and soil repellent finishing agent, was established by in-port derivatization/gas chromatography/mass spectrometry method..The research includes the following several aspects:1. Sample pretreatment:the ultrasonic-microwave synergistic extraction, which was the suitable extracting method for PFOS in textiles, was established. The best extraction conditions were determined by monofactorial experiment. 2. The detecting method research:the quantitative analysis of the butyl-PFOS derivative was studied by in-port derivatization/GC/MS method. The retention time and characteristic ions were used for the qualitative analusis and the external standard method was employed for the quantitative analysis. The DB-5 chromatographic column was applied for the separation of PFOS in textile samples and the parameters of instrument were optimized. Finally, the PFOS in textile samples was separated effectively and detected successfully.3. The in-port derivatization research:tetrabutylammonium hydroxide (TBAH) was used as a derivative reagent via an in situ pyrolytic alkylation reaction which was occurred in the GC injector and finally the derivative of butyl-PFOS was detected by GC/MS. The best conditions of the derivative reaction were optimized by monofactorial experiment and the detecting method of in-port derivatization/GC/MS was determined.The research results indicated that the detection limits of method were 0.0588ug/mL. The linear range was from 0.5μg/mL to 10μg/mL. The recovery was 80%-100%, which was met the requirement for the real sample analysis. And the relative standard deviation (RSD) was less than 10%. The concentrations of PFOS in the textiles ranged from 0.06 to 13.86mg/kg. In addition, the value of peak area was changed little, and the retention time was also stable. It was illustrated that the method was sensitive, rapid with high recovery which could be used for the determination of the content of PFOS in textiles.