固相支持液液萃取-气相色谱质谱法测定酱油和醋中对羟基苯甲酸酯类防腐剂

Determination of Parabens in Soy Sauce and Vinegar by Supported Liquid Extraction(SLE)-Gas Chromatography Mass Spectrometry

建立了酱油和醋中4种对羟基苯甲酸酯类化合物的固相支持液液萃取(SLE)气相色谱质谱测定的方法。目标化合物包括对羟基苯甲酸甲酯(MeP)、对羟基苯甲酸乙酯(EtP)、对羟基苯甲酸丙酯(PrP)、对羟基苯甲酸丁酯(BuP)。样品上固相支持液液萃取小柱(Chem Elut S硅藻土柱),静置15 min后,先用正己烷淋洗小柱,然后用二氯甲烷洗脱,洗脱液于40℃下减压浓缩至近干,无水乙醇复溶后进行气相色谱-质谱测定。4种对羟基苯甲酸酯类化合物在0.050~1.00μg/mL范围内线性良好,R^(2)均不小于0.999,4种化合物的检出限和定量限分别为0.02 mg/kg和0.05 mg/kg。空白食醋和空白酱油样品3个水平的加标试验(0.05、0.1、0.25 mg/kg),4种化合物的加标回收率和相对标准偏差(RSD,n=6)分别为86.1%~103.5%(RSD=0.7%~7.7%)、83.9%~112.9%(RSD=1.7%~3.5%)、79.2%~102.4%(RSD=2.2%~7.7%)和81.5%~93.0%(RSD=3.7%~8.4%)。该方法简便快捷,提高了样品处理的通量,节约了样品处理的时间和有机试剂的用量,应用于实际样品能获得较为满意的结果。

Method of determining four kinds of parabens in soy sauce and vinegar by supported liquid extraction(SLE)-gas chromatography mass spectrometry was established.The target compounds were methyl paraben(MeP),ethyl paraben(EtP),propyl paraben(PrP)and butyl paraben(BuP).The sample was added to Chem Elut S SPE cartridge slowly,after standing for 15 minutes,the cartridge was first rinsed with n-hexane,and then eluted with dichloromethane.The eluent was evaporated at 40℃to nearly dry and dissolution in ethanol,then performed by gas chromatography-mass spectrometry.The parabens showed good linearity in the range of 0.050~1.0μg/mL,and the square of correlation coefficient(R2)was not less than 0.999.The limits of detection(LOD)and limit of quantification(LOQ)for parabens were 0.02 mg/kg and 0.05 mg/kg respectively.The recovery and the relative standard deviation(RSD,n=6)for the bland spiked vinegar and soy sauce samples with three levels(0.05,0.1,0.25 mg/kg)were 86.1%~103.5%(RSD=0.7%~7.7%),83.9%~112.9%(RSD=1.7%~3.5%),79.2%~102.4%(RSD=2.2%~7.7%)and 81.5%~93.0%(RSD=3.7%~8.4%)respectively.It showed that the method was rapid,simple,improves the throughput of sample processing,greatly saves the time of sample processing and the amount of organic reagents.The established method was applied to the determination of real samples,and the results were satisfactory.