Analytical Method Research For Kinds Of Volatile Organic Compounds

Volatile organic compounds(VOCs),which have boiling point ranging from 50℃to 250℃and saturated vapor pressure more than 133.32 Pa at room temperature,can be absorbed into the blood system through the digestive tract,respiratory tract or skin absorption.The harmful VOCs exited in air would lead to several negative effects on human ecosystem,such as allergy,asthma,acute respiratory infections,lung disease and so on.What is more,some VOCs contribute to the reproductive toxicity,neurotoxicity and carcinogenicity.In order to analyze multiple classed of VOCs,this study established Static Headspace-Gas chromatography-Mass spectrometry(SHS-GC-MS)analysis method for the determination of 32VOCs and Environment test chamber-Thermal desorption-Gas chromatography/Mass spectrometry(ETC-TD-GC/MS)analysis method for the determination of 69 VOCs,respectively.The full text is composed of two parts.PartⅠSimultaneous determination of 32 VOCs by SHS-GC-MSObjective:An analytical method was developed for the simultaneous determination of 32 VOCs by SHS-GC-MS.Method:The equilibrium temperature was set at 90℃for 30 min,the loop temperature and the transfer line temperature were set at 100℃and 120℃,respectively.The injector temperature was set at 230℃with 10:1 split ratio and the helium gas(purity≥99.999%)was used at a flow rate of 1.0 mL/min.The chromatography separation of target compounds was performed on a CP-WAX52CB capillary column(60.0 m×0.25 mm×0.25μm)and the column oven temperature was initially maintained at 40℃and held for 5min,gradually increased to 130℃for 10 min at a rate of 6℃/min,finally to230℃at a rate of 10℃/min and kept for 5 min at that temperature.The transfer line temperature and the ion source temperature were kept at 250℃and 230℃,respectively.Electron impact source was obtained with electron energy of 70 eV and the mass spectrometer was operated in selected ion-monitoring mode(SIM).Results:The 32 VOCs showed good linear relationships in the range of 0.05~12.5μg/g,0.125~12.5μg/g and0.25~12.5μg/g with correlation coefficients(R~2)ranged between0.9944~0.9998,the limit of detection(LOD)and the limit of quantification(LOQ)of the target compounds were in the range of 0.004~0.032μg/g and0.013~0.099μg/g,respectively.The recoveries of 32 VOCs at low concentration,medium concentration and high concentration were in the range of 71.4%~108.5%with RSDs ranged between 1.8%to 12.9%.Conclusion:The method is of high sensitivity and repeatability,which can be used to determine the 32 VOCs in mattress fabrics.PartⅡSimultaneous determination of 69 VOCs by ETC-TD-GC/MSObjective:To establish ETC-TD-GC/MS method for the determination of 69 VOCs.Method:Desorption of the analytes on the multisorbent tubes(Carbopack C,Carbopack B and Carboxen 1000)were carried out at 280℃for 10 min with pure helium passed through the tube at a flow rate of 50 mL/min in splitless mode,and then focus all of the analytes into the cold trap,which was maintained at-10℃,after the first desorption,the trap was rapidly heated from-10℃to 300℃and kept for 8min at that temperature with a spilt flow of 10 mL/min.The chromatography separation of target compounds was performed on a CP-WAX52CB capillary column and the column oven temperature was initially held at 40℃for 5min,gradually raised to 100℃for 3 min at a rate of 3℃/min,then increased to 230℃at a rate of 10℃/min and held for 5min at that temperature.The mass spectrometer was performed in SIM mode with electron impact energy of 70 eV,the transfer line temperature and ion source temperature were kept at 250℃and 230℃,respectively.Results:good linear relationships were observed in the range of 1~100 ng with R~2 ranged between 0.9965~0.9999,the method detection limit(MDL)and method quantification limit(MQL)of the target compounds were in the range of 0.006~0.561μg/m~3 and 0.020~1.870μg/m~3,respectively.The recoveries of 69 VOCs were in the range of 82.0%~106.7%with RSDs ranged between 1.0%to 10.0%.Conclusion:The method is of low MDLs,good repeatability and high accuracy,which can be used to determine 69VOCs in mattresses.