Determination Of Short Chain Chlorinated Paraffins By Carbon Skeleton Gas Chromatography Mass Spectrometry

In recent years,with the rapid development of economic globalization,China's export trade of textiles has become more prosperous,and the domestic ecological technology testing standards for textiles has also been constantly improved.However,there is still a certain gap between China and some developed countries in the green standards.The export of textiles has been recalled due to the continuously detection of short chain chlorinated paraffins(SCCPs).Short chain chlorinated paraffins have been widely concerned for their bioaccumulation,persistence,long-distance migration and biological toxicity.Many countries and organizations have issued relevant laws and regulations to prohibit or limit the use of SCCPs.At present,the instruments used for quantitatively analysis of SCCPs are different between laboratories,which are easily interfered by other factors and can not be effectively compared.The detection results of each instrument have the shortcomings of quantitative inaccuracy.(?)Preparation of reaction liner tube and characterization of its catalytic performance.In this paper,Pd was loaded on chromatographic support glass beads by immersion method,filled in a splitless liner tube,and reduced in the presence of hydrogen.The catalyst was characterized by energy dispersive X-ray spectrometer and X-ray diffraction,and the catalytic performance of Pd was characterized with 1,10-dichlorodecane as the reactant,and the effect of calcium carbonate on liner packing was explored.The results show that Pd²⁺is successfully reduced to elemental Pd,and Pd is evenly distributed on the surface of the carrier glass beads.This distribution is beneficial to provide more catalytically active sites,which is compared with the formation of reactants.The large reaction contact area effectively improves the catalytic activity of the catalyst.Under the catalysis of Pd,1,10-dichlorodecane can be completely reduced to decane,which proves that the catalytic performance of Pd is excellent.With the increase of temperature,the catalytic performance of Pd first increases and then decreases,and the catalytic performance is optimal at280?.The catalytic efficiency of 1,10-dichlorodecane reaches 99.52%.At 280?,the catalytic efficiency of Pd for different concentrations of 1,10-dichlorodecane reaches more than 98%,which indicates that the concentration has little effect on the catalytic system.Calcium carbonate plays an important role in adsorption of HCl,which generated from catalytic dechlorination hydrogenation reaction in the filling of reaction liner tube.(?)The catalytic dechlorination and hydrogenation technology of typical SCCPs.Based on that the typical SCCPs's similar structure with SCCPs,and the structure is clear and simple,typical SCCPs(monochlorodecane,undecane-chloride and chlorododecane)are used as the research objects,the effects of inlet temperature,reaction concentration,carbon chain length and chlorine content of SCCPs on the catalytic efficiency of Pd catalysts were systematically analyzed,and the catalytic performance was evaluated.The results show that with the increase of the inlet temperature,the catalytic efficiency of typical SCCPs increased first and then decreased.The highest catalytic efficiency is obtained at 280?,and the catalytic efficiency for mono-chlorodecane,undecane-chloride,chlorododecane is 99.99%,98.93%,99.55%,respectively.At280?,for different concentrations of typical SCCPs,the catalytic efficiency of Pd is above 85%,which indicates that the concentration has little effect on the catalytic system and is within the allowable error range of the experiment.And Pd shows similar catalytic efficiency for typical SCCPs with different carbon chain length and different chlorine content.The above results can lay a solid theoretical foundation for the quantitative method of carbon skeleton gas chromatography mass spectrometry for SCCPs.(?)Carbon skeleton gas chromatography mass spectrometry for the quantification of SCCPs in textiles.In this paper,carbon skeleton gas chromatography-mass spectrometry was applied to quantify SCCPs in textiles and was investigated in methodology.In this method,SCCPs were reduced to corresponding alkanes by Pd,and quantified by the total peak area of alkanes generated by the conversion and he external standard method.The results show that SCCPs can be separated according to the length of carbon chain by carbon skeleton gas chromatography mass spectrometry,and the information of total SCCPs can be obtained.The linear correlation of this method was good(r=0.9998).The recoveries in textiles are between 83.68%and 98.60%,the RSD is between3.18%and 4.95%,and the detection limit is 1.2 mg·kg^-1.The method has good precision,accuracy and sensitivity,and meets the requirements of SCCPs quantitification in actual textiles samples.