Study Of Application Of Novel Sample Pretreatment Techniques In Harmful Substances Testing For Textiles

In currently accepted testing methods on pretreatment of textile samples, some conventional techniques such as Soxhlet extraction, ultrasonic extraction, liquid-liquid extraction were widely used. They are time-consuming and tedious. In addition, they always use a large volume of hazardous organic solvent and employ concentration procedures associated with the high risk of analyte losses. Nowadays, attention is focused on techniques that are rapid, simple, efficient, low-cost, and environmentally friendly by reduction or complete elimination of organic solvents.In this work, the applications of several types of novel sample pretreatment methods such as dispersive liquid-liquid microextraction (DLLME), pressurized hot water extraction (PHWE), solvent induced phase transition extraction (SIPTE) in potentially harmful substances testing for textiles were investigated. The aim of the study was to develop environmental-friendly, efficient, rapid and simple testing methods, not only reducing cost and labor intensity but increasing sensitivity and selectivity compared to existed methods.In Chapter one, the current situation and underlying questions of the conventional testing methods of harmful substances in textiles were pointed out. The chapter then focused on the introduction of several novel sample pretreatment methods such as dispersive liquid-liquid microextraction, vortex-assisted liquid-liquid microextraction, pressurized hot water extraction, accelerated solvent extraction, solvent induced phase transition extraction and their applications.In Chapter two, a dispersive liquid-liquid microextraction procedure coupled with gas chromatography-mass spectrometry was described for preconcentration and determination of10banned aromatic amines from textile samples. In this method, chlorobenzene and acetonitrile were used as extraction solvent and disperser solvent respectively. Experimental conditions affecting the microextraction procedure such as types and volumes of extraction solvent or disperser solvent, extraction time, salt concentration were optimized. Compared with the traditional liquid-liquid extraction, the proposed method demonstrated to be a simple, rapid, accurate, low-cost and environmentally friendly technique. In Chapter three, an ionic liquid-based vortex-assisted liquid-liquid microextraction coupled with high performance liquid chromatography was established to rapidly extract the aromatic amines in aqueous solution. Replacing toxic halogenated hydrocarbons with hydrophilic ionic liquid as extraction solvent was to avoid exposure danger to solvent for the operator. Moreover, the proposed method was faster, simpler, and more environment-friendly due to the dispersion of extraction organic solvent directly into the aqueous phase was achieved by vortex agitation rather than using disperser solvent.In Chapter four, for the first time, a simple extraction method termed solvent induced phase transition extraction was used for the analysis of banned aromatic amines in textile samples. The most favorable extraction variables in the extraction process were determined. The proposed method was much simpler and less time-consuming, it gave higher sensitivity, and used minimal amounts of organic solvents compared to previous existing methods.In Chapter five, the combination of pressurized hot water extraction with vortex-assisted liquid-liquid microextraction for sample preparation prior to gas chromatography-mass spectrometry analysis of chlorobenzenes in textiles was firstly reported here. Main factors potentially affecting the two extraction processes were evaluated and optimized. The developed method was then successfully used to analyze chlorobenzenes in real textile samples and was compared with the results from classical Soxhlet extraction and ultrasonic extraction. From the results obtained, the proposed method could be considered a reliable, low-cost approach and more environmentally friendly because it minimized the use of toxic organic solvents.In Chapter six, a simple, rapid, efficient and environmentally friendly sample preparation procedure coupled with gas chromatography-mass spectrometry was developed to assay dimethyl fumarate in textiles and leathers. The sample preparation procedure involved an accelerated solvent extraction using water as the extract solvent, followed by the extraction and concentration of dimethyl fumarate from the aqueous solution using vortex-assisted liquid-liquid microextraction. The developed method was successfully applied to textiles and leather samples.