Analysis of UV ink photoinitiators in packaged food by fast liquid chromatography at sub-ambient temperature coupled to tandem mass spectrometry

A fast method of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was developed for the analysis of eleven UV ink photoinitiators in packaged food. Chromatographic separation was achieved in a pentafluorophenylpropyl (PFPP) column at 5°C and acetonitrile:25 mM formic acid-ammonium formate (pH 2.7) in gradient elution. To reduce sample treatment, a QuEChERS (quick, easy, cheap, effective, rugged and safe) method for the extraction and clean-up of UV photoinitiators in packaged foods was evaluated. Triple quadrupole working in H-SRM on Q1 mode was used for both quantitation and confirmation purposes and the most intense and selective transitions were chosen. Quality parameters of the developed QuEChERS LC-MS/MS method were established and applied for the analysis of photoinitiators in food packaged at ng kg(-1) levels.     

Determination of pesticides in compost by pressurized liquid extraction and gas chromatography-mass spectrometry

A gas chromatographic-mass spectrometric method was developed for the determination of pesticides in compost. The investigated pesticides included two fungicides, two herbicides and 10 insecticides. The pesticides were extracted from the compost by pressurized liquid extraction. The extract was cleaned up by a partition between hexane and acetonitrile followed by a dispersive solid-phase extraction using a porous carbon made from Moso bamboo (Phyllostachys pubescens). The overall recoveries were 81-104% and the relative standard deviations (RSDs) ranged from 2.4 to 12%. The minimum detectable concentrations were 0.02-0.04 microg g(-1). This method was successfully applied to a compost sample from food waste as well as commercial compost.     

固相微萃取-气相色谱/质谱法测定果汁及茶饮料中的10种光引发剂

建立了用固相微萃取结合气相色谱/质谱（GC/MS）检测13种果汁饮料和3种茶饮料中10种光引发剂的方法。通过正交试验筛选对萃取过程影响较大的因素,再通过单因素试验进一步优化,确定最佳的操作条件。样品经萃取后,在GC/MS进样口解吸3 min,经HP-5MS色谱柱分离,以选择离子方式监测,外标法定量。为消除基质的干扰,以样品基质加标做工作曲线,线性范围为0.3~60 μg/L,检出限为3~16 ng/L。分别对4个不同加标水平的样品平行测定5次,相对标准偏差均小于14.5%。对不同品牌、不同种类的16种盒装饮料进行了测定,所有样品中全部检出二苯甲酮,部分样品中检出对二甲氨基苯甲酸异辛酯、2-异丙基硫杂蒽酮、4-甲基二苯甲酮、1-羟基环己基苯基甲酮、2-氯噻吨酮。该方法操作简单、灵敏度高、无污染,可对10种光引发剂同时测定。该研究结果为从包装材料迁移至饮料中的光引发剂的测定提供了参考。     

Determination of sialic acids by liquid chromatography-mass spectrometry

Sialic acids are widely found in nature as components of oligosaccharide units in mucins, glycoproteins and other microbial polymers. Existing methods for determining these acids are long, tedious, and not specific. A simple, rapid, and sensitive method for determining the most commonly occurring acids, N-acetylneuraminic and N-glycolylneuraminic acid, using LC-MS is described. Standard solutions of the sialic acids with the internal standard, N-acetylneuraminic acid methyl ester, were quantitatively analyzed by positive ion electrospray ionization. Fetuin was used as a model glycoprotein and the hydrolysate was injected directly onto an ES Industries AquaSep 3 microm 150x4.6 mm column eluted with a 0.1% aqueous formic acid mobile phase at a flow-rate of 0.5 ml/min. Detection was achieved using the Finnigan Navigator MS system in the selected ion monitoring mode for the protonated molecular ions at m/z 310, 324, and 326. The linearity over the dynamic range 10 to 1000 ng of sialic acids on-column had a correlation coefficient greater than 0.999. The amount of sialic acids found in the fetuin hydrolysate was in agreement with values reported in the literature.     

GC-MS直接测定芥酸酰胺

通常衍生后的酰胺才能用气相色谱测定.在实验几种酰胺衍生化方法时发现衍生反应不彻底剩余的芥酸酰胺也能出峰.进一步实验表明:芥酸酰胺在295 ℃气化后可直接测定,该法以邻苯二甲酸二丁酯为内标,质量浓度在115.4～923.2 mg/L 范围内线性关系良好,样品回收率94.85%～98.04%,芥酸酰胺的检出限5.77 mg/L.     

液相色谱-质谱法测定饲料中阿维菌素类药物

建立了饲料中阿维菌素类药物(阿维菌素、多拉菌素、埃普菌素和伊维菌素)液相色谱-质谱(LC-MS)检测法. 用乙腈提取样品中的药物, 加水稀释, 加三乙胺调节pH, 经C18固相萃取柱净化, LC-MS法测定. 结果表明, 方法平均回收率为91.3%～99.8%, RSD为2.9%～15% (n=4), 配合饲料、浓缩饲料和预混合饲料中的检出限均为10 μg/kg; 定量限均为20 μg/kg. 方法可用于饲料样品中阿维菌素类药物残留量的确证检测.     

Determination of zopiclone in urine by gas chromatography-mass spectrometry

A procedure is described for the quantitative determination of zopiclone and the sum of its metabolites in urine using gas chromatography with the mass-spectrometric detection of their common hydrolysis product, 6-(5-chloro-2-pyridyl)-7-hydroxy-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazine-5-on. The procedure is very sensitive. The detection limit for ions with a mass of 45–450 au detected in the full scanning mode is 70 ng/mL. The data of gas chromatography-mass spectrometry are presented for different derivatives of the hydrolysis product of zopiclone; these data can be used for the qualitative identification of zopiclone. The stability of zopiclone and its metabolites upon time was studied by analyzing urine samples from patients receiving therapeutic doses of this substance stored for 1, 3, and 6 months.     

Determination of selenoamino acids by gas chromatography-mass spectrometry

The application of the recently introduced ethylchloroformate derivatization method for the separation and determination of selenomethionine and selenocystein in selenium-enriched yeast and yeast-free tablets by means of a gas chromatography-mass spectrometry (GC-MS) system has been studied. The efficiency of three methods for the extraction of selenomethionine from the tablets were compared. Total selenium content of the same tablets were measured using inductively coupled plasma (ICP)-MS and it was found that in the selenized yeast tablets about 80% of the total selenium is present as selenomethionine. The results were in agreement with the values in the labels and with the literature. The accuracy of the total selenium analysis was controlled by the analysis of a reference material.     

液相色谱-质谱法测定水中的苯胺

按照HJ68-2010,建立了液相色谱-质谱法测定水中苯胺的方法.在优化条件后,该方法展示了优异的性能:(a)在10～ 200μg/L范围内具有良好的线性关系,相关系数R为0.9997; (b)与其它方法相比,有较低的检出限,检出限仅为2.0μg/L;(c)精密度和准确度较好,相对标准偏差RSD<6%,空白水样加标回收...     

气相色谱-质谱联用法测定紫菜中扑草净的残留量

建立了固相萃取净化与气相色谱-质谱联用技术测定紫菜中扑草净除草剂残留量的检测方法。样品由乙腈溶剂提取浓缩后,活性炭和氨基柱双柱串联固相萃取净化,由气相色谱-质谱联用技术测定。方法定量限为2μg/kg,满足国外最低10μg/kg的限量要求;方法在10,40和100μg/kg 3个添加水平和不同人员操作条件下,回收率均稳定在90%~120%之间,RSD%≤7.1%。     

气相色谱-质谱法检测涂料中的六溴环十二烷

建立了防火涂料中阻燃剂六溴环十二烷(HBCD)的气相色谱-质谱(GC-MS)分析方法。样品用二氯甲烷进行萃取,萃取液经有机滤膜过滤后,用气相色谱-质谱联用仪进行测定。在选择离子检测模式下以m/z 157、239、319、401为定性离子,m/z 239为定量离子进行结构确证和定量检测。在优化的实验条件下,六溴环十二烷标准溶液在5~100 mg/L的质量浓度范围内线性关系良好,相关系数大于0.999。对市售的空白丙烯酸树脂涂料样品及环氧树脂涂料样品进行加标回收试验,结果表明本方法的平均回收率为92.9%~116.3%, RSD不超过8%。方法的检出限(S/N=3)为30 μg/g,定量限(S/N=10)为100 μg/g。本方法简便、快速、准确性好、精密度高,能够满足检测工作的实际要求。     

气相色谱-质谱法测定化妆品中的三氯叔丁醇

建立了测定化妆品中三氯叔丁醇的气相色谱-质谱分析方法.膏霜、水剂、散粉、香波、唇膏等不同类型的化妆品样品加入50％甲醇-无水乙醇或无水乙醇超声提取后,样品提取液高速离心处理,取上清液经无水硫酸钠脱水,进行气相色谱-质谱定性及定量分析.选用DB-1701(30 m×0.25 mm×0.25μm)石英毛细管柱,程序升温,流...     

气相色谱-质谱法测定水中痕量的四乙基铅

建立了气相色谱-质谱(GC-MS)测定水中痕量四乙基铅的分析方法。用正己烷萃取水样中的四乙基铅,萃取液浓缩后加入同位素内标萘-d8,采用GC-MS选择离子方式(SIM)进行检测,在200 mL水样中四乙基铅的检出限可达0.04 μg/L;添加回收率为92.2%～103%,准确度好;平行5次测定的相对标准差为4.4%～13.3%。结果表明: 方法简便、快速、准确、实用,可用于水中痕量四乙基铅的测定。     

液相色谱串联质谱测定液态乳制品中7种光引发剂的迁移量

建立了同时测定液态乳制品中7种光引发剂迁移量的液相色谱质谱法,方法采用混合溶液超声提取样品中光引发剂后,亲水亲脂填料固相萃取柱净化,色谱分离采用MGⅡC18柱,电喷雾正离子多反应监测模式下监测,同位素内标法定量。7种光引发剂的检出限为0.1~5μg/kg;在三个添加浓度水平时回收率为65%~110%,相对标准偏差为5.4%~14%。该方法可确证乳饮料中7种光引发剂的迁移量。     

蜂蜜中氯霉素残留的气质分析方法研究

氯霉素(chloramphenicol)又名左旋霉素,是一类广谱抗生素,作为药物常用于家禽疾病治疗和预防.氯霉素对人的造血系统、消化系统具有严重的毒性反应,有可能引发人的再生障碍性贫血.因此欧盟等国家规定蜂蜜及其它动物源食品中氯霉素的最高残留量不得超过0.1μg/kg.本文对蜂蜜样品的提取、净化和富集方法进行了较为系统地研究,建立了固相萃取-气相色谱-质谱联机分析蜂蜜中的氯霉素残留量的方法.对氯霉素在固相萃取柱上的保留行为进行了研究,优化固相萃取条件,发现在选定的条件下,不同浓度的氯霉素在硅胶柱和C18柱上的回收率均在90%以上,蜂蜜加标的回收率在80%～95%,相对标准偏差在7.2%～18.2%,最低检出限为0.1μg/kg.对氯霉素的三甲基硅烷化衍生物采用选择离子的模式进行检测(376,378,466、468、470),衍生物的峰面积与样品浓度在0.55～220 ng/mL范围内呈良好的线性关系,线性回归系数为0.9998.     

气相色谱-质谱和液相色谱-质谱联用方法用于口腔癌代谢组学分析

口腔癌的发病率占全身恶性肿瘤的第6位,正确区分正常状态与良性和恶性口腔肿瘤,是恰当选择治疗方案的关键所在。本研究中,首先利用液相色谱-质谱和气相色谱-质谱联用方法分别得到健康人、良性口腔肿瘤患者和恶性口腔肿瘤患者血浆、尿液和唾液的代谢轮廓,然后应用正交信号校正的偏最小二乘法进行多变量统计分析。结果表明健康人、良性肿瘤患者和恶性肿瘤患者在血浆、尿液和唾液等3种体液代谢中都可以被区分开,而且找到和鉴定出19个重要差异代谢物。相关代谢通路分析显示,与健康人相比,良性和恶性口腔肿瘤患者都存在能量代谢紊乱和脂类代谢失衡的现象,但恶性口腔肿瘤患者还表现出三羧酸循环和肌醇代谢异常,这为临床诊断及治疗提供了重要信息。     

Derivatization followed by gas chromatography-mass spectrometry for quantification of ethyl carbamate in alcoholic beverages

A sensitive and rapid analytical methodology based on derivatization followed by gas chromatography-mass spectrometry (GC-MS) was developed for the quantitative determination of the toxic contaminant ethyl carbamate (EC, urethane, C(2)H(5)OCONH(2)) in alcoholic samples. EC was extracted using liquid-liquid extraction technique, and then silylated with bis-(trimethylsilyl)trifluoroacetamide, analysed finally by GC-MS. The isopropyl carbamate was used as the internal standard for quantitative analysis of EC in alcoholic samples. In this work, the sample extraction and derivatization reaction conditions were investigated, and the optimal extraction conditions obtained were: pH 9 and solvent of ethyl acetate, and the derivatization conditions were: derivatization reaction temperature of 80°C and time duration of 30 min. With the optimal conditions, the method validations were also studied. In the validation studies, EC exhibited good linearity with a regression coefficient of 0.9999. The limit of detection and limit of quantification were 0.30 and 5.0 μg/kg, respectively. The precision was less than 8.4%. Finally, the proposed technique was successfully applied to the analysis of EC in 35 kinds of alcoholic samples. The experimental results have demonstrated that the proposed technique is a fast, reliable and low-cost method for determination of EC in alcoholic samples.     

液相色谱-电喷雾电离质谱法检测尿液中的3种合成类固醇药物

研究建立了合成类固醇药物群勃龙、四氢孕三烯炔酮和孕三烯酮的液相色谱-电喷雾质谱的检测方法。尿样经过β-葡萄糖醛酸酶酶解和叔丁基甲醚提取后,采用Zorbax SB-C18分析柱(150 mm×2.1 mm,5 μm),在流动相为pH 3.5的甲酸铵缓冲液-乙腈的条件下进行梯度洗脱,在正离子模式下检测。考察了不同的质谱条件对这类化合物检测结果的影响。建立了人尿液中合成类固醇药物的液相色谱-电喷雾电离质谱的初筛和确证方法。