Study On Residual Behavior Of Tetrachloroethylene In Dry Cleaning Fabrics

Tetrachloroethylene (PCE)was currently one of the most widely used dry cleaningsolvents. Its toxic effects on the human body mainly wasinhibiting the central nervoussystemand impairing the liver and kidneys, the person whose symptom waslightappeared headaches, burning eyes, unconsciousness and other diseases, the personwhose symptom was serious may even lead to death. There were no uniforminternational standards for the safety controls of residual tetrachloroethylene in the drycleaningfabrics. Therefore, we urgently need to study the residue behavior oftetrachloroethylene in the dry cleaning fabrics. The following experiment was carriedout four studies, the results were as follows.①Firstly, headspacegas chromatography (HS-GC), ultrasonic assisted extractiontechniquegas chromatography mass spectrometry (UE-GC-MS), and solid phasemicro-extraction gas chromatography mass spectrometry (SPME-GC-MS)were used toestablish the three methods for the detection of tetrachloroethylene. Optimalexperimental conditions were as follows.To the method of headspace gas chromatography (HS-GC),the column ofTG-200MS was used in the experiment, also hexane was used as solvent, andtrichloroethane was used as internal standard.The heating procedure was keeping theinitial temperature at40°C for1min, then increasing to200°C at a rate of50°C/minfor3min. The condition of headspace was as follows. The carrier gas pressure was120kPa, the pressing time was30s, the injection time was5s, the emptying time was20s, the heating time was5min, the heating temperature was80℃, the syringetemperature was65℃,and the transfer line temperature was80℃.To the method of ultrasonic assisted extraction technique gas chromatography massspectrometry (UE-GC-MS), the column of TG-624was used in the experiment, alsohexane was used as solvent, and chlorobenzene was used as internal standard. Theheating procedure was keeping the initial temperature at40°C for4min, thenincreasing to130°C at a rate of40°C/min for4min, and the solvent delay time was5min. The condition of ultrasonic assisted extraction was as follows.The temperaturewas50℃, the ultrasound time was10min.To the method of solid phase micro-extraction gas chromatography massspectrometry (SPME-GC-MS), methanol was used as solvent,100μm PDMS solid phase micro-extraction fiber head was used in the experiment. The experimentalcondition of headspace solid phase micro-extraction was as follows. The salt contentwas192g/L, the extraction time was5min, the extraction temperature was150℃, thespeed was400r/min, and the resolution time was20s.②Secondly, the linear relationship, linear range, sensitivity, the limit of detection(LOD: S/N=3) and the limit of quantification (LOQ: S/N=10)were used toevaluate themethod for the detection of tetrachloroethylene, the results were as follows. To themethod ofHS-GC,the linear relationship was Y=0.1821+0.2338X (R2=0.9986), thelinear range was0.5μg/L~50μg/L, the sensitivity was0.2338, the limit of detection was0.001μg/L, the limit of quantification was0.002μg/L.To the method of UE-GC-MS: thelinear relationship was Y=0.1747+0.0658X (R2=0.9993), the linear range was0.5mg/L~50mg/L, the sensitivity was0.0658, the limit of detection was5μg/L, the limitof quantification was10μg/L.③Thirdly, both of headspacegas chromatography (HS-GC) and ultrasonic assistedextraction technique gas chromatography mass spectrometry (UE-GC-MS) were usedfor analyzing the residues of tetrachloroethylene in the dry cleaning fabricThe resultsshowed that the residues of tetrachloroethylene were reduced with the extension ofstorage time, decreased withthe temperature increasing, increased with the humidityincreasing.④Lastly, through analyzing the residues of tetrachloroethylene in the dry cleaningfabric, some empirical models were established. The empirical models were tallywithpower distribution function. In the study, we found that the effective lifecycle oftetrachloroethylene of cotton, ramie, viscose, nitrile fiber was two days; the effectivelifecycle of tetrachloroethylene of silk was four days, the effective lifecycle oftetrachloroethylene of wool, polyester multi-fiber blend fabrics was six days.