Analysis of vinylidene chloride and 1-chlorobutane in foods packaged with polyvinylidene chloride casing films by headspace gas chromatography/mass spectrometry (GC/MS)

A headspace gas chromatography/mass spectrometry method was developed for the simultaneous determination of vinylidene chloride and 1-chlorobutane in foods packaged with polyvinylidene chloride casing films. The solid foodstuff was homogenized with an equal mass of distilled water. The homogenate was incubated for 1 h at 90°C in a sealed headspace vial, and the headspace gas was then analysed by gas chromatography/mass spectrometry in selected ion-monitoring mode using a bonded porous polymer-coated capillary column. The recovery rates of vinylidene chloride and 1-chlorobutane in foodstuffs were 94.5-103.9 and 85.8-120.3%, respectively. Among 13 samples tested, vinylidene chloride was detected at 0.001-0.020 µg g^-1 in 11 foodstuffs, and 1-chlorobutane was detected at 0.004-0.040 µg g^-1 in all 13 foodstuffs. Furthermore, vinylidene chloride was detected at 0.04 µg g^-1 in one casing film, and 1-chlorobutane was detected in all casing films. The results indicate that these compounds migrated from the casing films into the foodstuffs.     

气相色谱法测定聚氯乙烯薄膜中氯乙烯单体的方法研究

研究建立了手动顶空进样气相色谱法(GC)检测聚氯乙烯(PVC)薄膜中氯乙烯单体(VCM)的分析方法。实验对气相色谱参数和样品平衡条件进行了优化,选择在70℃平衡30min,采用DB-WAXtre极性毛细管气相色谱柱分离,氢火焰离子化检测器(FID)检测,所检测的对象完全分离,峰形良好。氯乙烯单体和峰面积在0~4.977μg的范围内有良好的线性关系,相关系数R2为0.9994,3倍信噪比确定检出限为0.20mg/kg。采用空白薄膜样品加标准品测定氯乙烯单体回收率及精密度,回收率在91.04%~103.27%之间,相对标准偏差RSD在3.76%~4.50%,方法重现性好,满足聚氯乙烯薄膜单体残留的分析。所测定的9种聚氯乙烯薄膜中氯乙烯单体的残留,均低于检测极限。     

气相色谱-串联质谱法同时测定肉制品中氯霉素、甲砜霉素残留

建立了肉制品中氯霉素、甲砜霉素的气相色谱串联质谱检测方法。样品经均质后,用乙酸乙酯提取,正己烷脱脂,弗罗里硅土小柱净化,衍生后用气相色谱串联质谱法检测,内标法定量。优化了二级质谱条件,包括离子对及碰撞电压。该方法检出限为氯霉素(CAP)0.02μg/kg,甲砜霉素(TAP)0.1μg/kg,加标回收率均在86%~97%之间,相对标准偏差(RSD)在3.8%~12.3%之间,在0.1~20 ng/mL范围内都呈现出良好线性关系。     

Determination of low-level pesticide residues in agricultural products by ion-trap GC/MS/MS

The objective of this study was to elucidate the utility of ion-trap GC/MS/MS for the analysis of pesticides in extracted matrices from various agricultural products. Identification and quantitative analysis of pesticides in matrices were performed by quadrupole GC/MS and ion-trap GC/MS/MS. Chlorpyrifos was added to the matrix of spinach, soybean in the pod or corn, and aldrin, dieldrin, endrin, alpha-BHC, beta-BHC, gamma-BHC, delta-BHC, p,p'-DDD, p,p'-DDE, o,p'-DDT and p,p'-DDT were added to each matrix of green tea, black tea or oolong tea. Although most of the pesticides in the matrix could not be determined by quadrupole GC/MS-Scan analysis at 0.1 microgram/mL, every pesticide was identified from the mass spectrum using ion-trap GC/MS/MS at the same concentration. The quantitation limit of every pesticide in each matrix by ion-trap GC/MS/MS analysis was higher than that by GC/MS-SIM analysis. The calibration curves obtained by GC/MS/MS were linear in the range of 0.01-0.25 microgram/mL of each pesticide. The recoveries of each pesticide from four kinds of samples spiked at the levels of 0.01 ppm to 0.02 ppm in extracts were 61.2-138.3% with SD values in the range from 1.2 to 15.4%. This study revealed that ion-trap GC/MS/MS was useful for the identification and quantitative analysis of low-level pesticides residues in matrices of agricultural products.     

Multiresidue analysis of pesticides in agricultural products by GC/MS coupled with database software

We evaluated a multiresidue method for determination of pesticides in agricultural products by SCAN mode GC/MS coupled with three kinds of database for 253 pesticides: relative retention time, mass spectra and calibration curve (SCAN method). Twenty-six pesticides, a total of 131 pesticides were detected in samples by the SCAN method. The detection results agreed closely with those of the SIM mode GC/MS method using calibration standards (SIM method). The ratios of the SCAN method to the SIM method ranged from 0.3 to 3.1 with SD values of 0.63. It was judged that the SCAN method could be applied to the screening analysis of pesticide residues in agricultural products, provided that the sample preparation method makes it possible to effectively remove sample matrixes with minimal loss of analytes.     

固相微萃取-气质联用分析沙茶酱香气物质的研究

目的用顶空固相微萃取-气质联用技术分析沙茶酱中的香气物质。方法优化萃取纤维种类、萃取时间及萃取温度,确定了较佳的萃取条件,进行质谱分析及检索。结果共检测到42种化合物,主要有茴香脑、芳樟醇、烯丙基甲基硫醚、二烯丙基二硫醚等。结论顶空固相微萃取-气质联用可用于沙茶酱中香气物质的快速分析。     

Research Watch: GC/MS analysis

Measurements.     

Determination of 66 pesticide residues in livestock products using QuEChERS and GC–MS/MS

Food Science and Biotechnology - Determinations of 66 pesticide residues in different matrices including beef, pork, chicken, eggs, and milk were conducted using GC–MS/MS combined with the...     

不同固相微萃取头-GC/MS联用测定干辣椒中香气组分的比较

采用顶空固相微萃取-GC/MS联用对干辣椒中的香气成分进行了初步分析,用4种不同涂层的SPME鉴定了干辣椒中的63种成分,比较了其对干辣椒中香气成分的萃取效果和特点,该实验显示选用PDMS或DVB/CAR/PDMS萃取头较佳.     

The analysis of fluvalinate in beeswax using GC/MS

A method for quantitation of the synthetic pyrethroid fluvalinate in beeswax has been developed. The method uses the internal standard permethrin added in the first acetonitrile extraction step. Subsequent cleanup involves partitioning into ether and use of a florisil column. The final gas chromatography was performed on a capillary column with selected ion monitoring detection using a mass spectrometer. The presence of fluvalinate was confirmed by the retention times of two identical peaks which had a 75:25 area ratio of the peaks at m/z of 250:252 (ion contains chlorine). Fluvalinate recovery of 108 and 97% were obtained at the 0.52 and 1.04 ppm spike level (respectively) using peak area calculations. The detection limit was determined to be 0.05 ppm.     

蓖麻油生物柴油的减压蒸馏及气-质谱分析

分别以浓硫酸和氢氧化钠为催化剂,以蓖麻油和甲醇为原料制备了生物柴油样品,并对其进行了减压蒸馏.用气-质联用仪对蒸馏样品进行了分析.结果表明:由蓖麻油制得的生物柴油主要成分为蓖麻酸甲酯,还含有少量油酸甲酯、亚油酸甲酯、十六酸甲酯及十八酸甲酯等成分;当减压蒸馏的液相温度较高、升温速率较慢时,少部分蓖麻酸甲酯将分解为10-十一烯酸甲酯和庚醛;当减压蒸馏的生物柴油样品含硫酸催化剂时,大部分蓖麻酸甲酯将发生脱水反应生成亚油酸甲酯.     

辽东湾产蛤蜊中脂肪酸组成的GC/MS分析

以无水乙醚为溶剂提取蛤蜊油,经皂化和甲酯化后利用气相色谱-质谱联用技术对其脂肪酸组成进行了分析和鉴定,共分离鉴定出15种脂肪酸,占总脂肪酸含量的89.76%。其中饱和脂肪酸的相对含量为50.77%,主要为十六烷酸(软脂酸)和十八烷酸(硬脂酸);不饱和脂肪酸的相对含量为38.99%,主要为二十碳五稀酸(EPA)、9-十六碳烯酸和11-二十碳烯酸。     

Material labeling of soft plastic toys and plasticizers in polyvinyl chloride products

We investigated the labeling and content of plasticizers of soft plastic toys. First, we investigated material labeling in 96 products purchased in fiscal years 2000 and 2001. Among these products, 43% of those purchased in fiscal 2000 and 68% of those purchased in fiscal 2001 were labeled. We then investigated the kinds and amounts of plasticizers in 73 soft polyvinyl chloride (PVC) toys. Three kinds of phthalates and six other kinds of plasticizers were detected in the soft PVC toys. Diisononyl phthalate, di(2-ethylhexyl) phthalate, diisononyl adipate, and O-acetyl tributyl citrate were detected at high frequency, and in large amounts. The average total content of all plasticizers was 280 mg/g for the products purchased in fiscal 2000 and 227 mg/g for those in fiscal 2001. In fiscal 2001, antioxidants, 4-nonylphenol, and bisphenol A were investigated in addition to plasticizers.     

GC/MS法分析烟用接装纸中挥发性有机化合物

建立了顶空-气质联用(HS-GC/MS)法,对烟用接装纸中挥发性有机化合物(VOCs)残留量进行测试.结果表明:(1)该方法检测限为0.001-0.004 mg/mL,回收率为89.35％- 108.96％,相对标准偏差(RSD)＜4％;(2)所有52个被检烟用接装纸榉品均为合格样品,所有样品中均未检出苯、乙苯、二甲苯、乙酸异丙酯、丁酮,YC171-2009《烟用接装纸》标准中规定的5种VOCs成分中只有乙酸正丁酯有个别检出;(3)醇类检出率较高,其中所有样品都有乙醇检出,异丙醇、正丁醇的检出率也比较高;(4)丙二醇甲醚有较高的检出率,且其检出量相对较大.研究结果充分说明,该方法适合于烟用接装纸中VOCs的快速批量检测.     

三种芳香植物抑菌比较及GC/MS分析

应用抑菌扩散法测定和比较了香桃木、薰衣草薄荷、迷迭香精油和残渣水提物的抑菌差异,进一步研究了精油经pH、温度、紫外处理后的抑菌稳定性,并对精油组分进行气相-质谱（GC/MS）分析。结果表明:3种精油均有明显的抑菌作用,且具有很好的抑菌稳定性。薰衣草薄荷精油抑菌活性明显高于其余两种精油,而香桃木精油和迷迭香精油的抑菌效果相差不大。GC/MS分析发现,精油中萜类物质含量分别为香桃木59.80%、薰衣草薄荷79.63%、迷迭香60.36%。残渣水提物提取率远高于精油,然而抑菌敏感性低于精油,并表现为香桃木>迷迭香>薰衣草薄荷。      

黑豆脂肪酸成分的GC/MS分析

采用石油醚抽提黑豆油,用氢氧化钾-甲醇法脂化后进行GC/MS分析,确认出14种脂肪酸,所鉴定组分占总峰面积的99.05%,其中脂肪酸主要成分相对含量:棕榈酸(16.40%),亚油酸(47.59%),油酸(14.19%),亚麻酸(6.36%),硬脂酸(10.10%)。     

Congener-specific analysis of Pcbs in food samples by using GC/MS

A GC/MS method for congener-specific analysis of polychlorinated biphenyls (PCBs) in food samples was evaluated. There was good agreement between total concentration of PCBs in fish samples (n = 16) measured by using the GC/MS method and the conventional GC-ECD method. The total diet study samples (fishery food, meat, egg, milk, and their products) collected from Osaka in 1982-2001 were analyzed by using the GC/MS method to estimate the temporal trend of daily intake of PCBs from food. The estimated daily intake of total PCBs (sum of tri- to heptaCBs) was in the range of 0.7-4.4 microg/person/day, far below the Japanese provisional acceptable daily intake (250 microg/50 kg-person/day). The dominant congener was 2,2',4,4',5,5'-hexachlorobiphenyl (#153), which accounted for 9-15% of total PCB. The ratio of lower chlorinated congeners decreased from the 1980's to post-2000. The results indicate that the PCB congener profile in foods has gradually changed.     

GC/MS法分析甘牛至油中香味成分

利用GC/MS对甘牛至油中香味成分进行了分析,并用峰面积归一化法计算各成分相对含量,通过质谱库检索,保留指数比对,分析并确定了58个化合物,占甘牛至油香味成分95.61%,采用保留指数来鉴别同系物及同分异构体,提高了对甘牛至油中成分定性的准确性。通过香气分析,确定了甘牛至油中关键致香成分分别为芳樟醇、α-松油醇、1,8-桉叶素、乙酸芳樟酯、α-蒎烯、β-蒎烯、月桂烯、莰烯、β-石竹烯、桧烯、樟脑、龙脑等,为甘牛至油产品开发和应用提供了理论依据。     

葡萄酒中氨基甲酸乙酯含量的HS-SPME/MPS结合GC/MS自动检测方法的研究

以氨基甲酸丙酯为内标物,采用顶空固相微萃取技术进行样品前处理,使用自动进样装置和气相色谱-质谱联用仪检测葡萄酒中氨基甲酸乙酯.通过对同相微萃取条件影响因素的正交设计和单因素试验研究,最终确定对葡萄酒样品的最佳萃取条件是萃取温度80℃、萃取时间30min、葡萄酒自然pH值、10mL葡萄洒添加3.5 gNaCl.该方法对葡萄酒中EC含量的测定较为准确.