气相色谱-质谱法测定空气清新剂中23种挥发性有机物

Determination of 23 Volatile Organic Compounds in Air Freshener by Gas Chromatography-Mass Spectrometry

应用气相色谱-质谱联用法测定空气清新剂中23种挥发性有机物(VOCs)的含量。取经预处理的样品0.500 0g于10mL刻度管中,加入混合内标溶液0.10mL作为定量依据,用三乙酸甘油酯定容至10.0mL,加入无水硫酸钠3g,涡旋脱水并静置1h后取上清液1.0mL,经滤膜过滤,取滤液按仪器工作条件进行操作。经试验,在样品的稀释以及内标溶液和VOCs标准溶液的配制中均选用三乙酸甘油酯作为稀释溶剂。混合内标溶液中包含两种化合物(丙二醇乙醚和溴苯),两者的质量浓度均为200mg·L-1;测定23种VOCs中的3种醚类化合物时用丙二醇乙醚为内标,测定其余化合物时以溴苯为内标。GC分离中选用DB-FFAP极性色谱柱和DB-1非极性色谱柱作为分离柱,DB-FFAP柱对23种VOCs和2种内标物均能达到良好分离,但由于样品含大量乙醇和水,干扰了苯、甲苯、α-蒎烯、丁酸乙酯和乙酸丁酯的分离,因此选用DB-1柱对以上5种化合物分离。所测定的23种VOCs的线性范围均在0.50～10.00mg·L-1之间,其检出限(3S/N)均小于10mg·kg-1。在10,20,100,200mg·kg-1等4个浓度水平上进行加标回收试验,测得回收率在88.3%～113%之间;测定值的相对标准偏差(n=6)除丙酮在加入量为10mg·kg-1时为6.5%,其他均小于5.0%。

GC-MS was applied to the determination of 23 volatile organic compounds(VOCs)in air freshener.The pretreated sample(0.5000 g)was placed in a graduated 10 mL tube and 0.10 mL of mixed internal standard solution was added for quantification.Triacetyl-glyceride was added to make its volume to 10.0 mL.Anhydrous Na2 SO4(3 g)was added and the mixture was swirled for dehydration.After standing for 1 h,1.0 mL of the supernatant was taken and filtered through 0.45μm filtering membrane.The filtrate was used for analysis by GC-MS according to the working conditions of the instruments.Triacetyl-glyceride was chosen as the solvent in dilution of sample solution and in preparation of standard solutions of VOCs and of internal standards.Two internal standard compounds,i.e.,ethoxypropanediol and bromobenzene were added in the mixed standard solution,with their concentrations same as 200 mg·L^-1.In the determination of 3 etheric compounds among the 23 VOCs,ethoxypropanediol was used as internal standard,and in the determination of the remainder compounds,bromobenzene was used as internal standard.The DB-FFAP polar column was satisfactorily effective for separation of both the 23 VOCs and the 2 internal standards,But due to interferences caused by high contents of ethanol and water in the sample,benzene,toluene,α-pinene,ethylbutyrate and butylacetate were separated on the non-polar DB-1 column.Linearity ranges of the 23 VOCs were found same between 0.50 to 10.00 mg·L^-1,and the detection limits(3 S/N)were found all less than 10 mg·kg^-1.Recovery was tested by standard addition method at 4 concentration levels of 10,20,100,200 mg·kg^-1,giving results in the range of 88.3%-113%.Values of RSDs(n=6)were found all lower than 5.0% with an exception of 6.5%for acetone at the concentration level of 10 mg·kg^-1.