气相色谱-质谱法测定化妆品中13种防晒剂

防晒剂广泛应用于化妆品中,是目前化妆品监管的重点。建立了同时测定化妆品中13种防晒剂的气相色谱-质谱(GC-MS)方法。化妆品样品经二氯甲烷提取后,涡旋超声后稀释。采用程序升温模式,经HP-5ms毛细管色谱柱(30 m×250 μm×0.25 μm)在30 min内对13种防晒剂实现分离,经电子轰击(EI)源电离后采用选择离子监测模式(SIM)扫描测定,外标法定量。比较了6种常用有机溶剂的基质效应和平均回收率,二氯甲烷的基质效应弱,平均回收率较高。13种防晒剂在相应的线性范围内线性关系良好,相关系数均大于0.998,检出限(LOD, S/N=3)为0.04~0.63 mg/g,定量限(LOQ, S/N=10)为0.12~2.10 mg/g。实验选取了两种基质,在3个水平下验证方法的回收率和精密度,13种防晒剂在霜类基质中的加标回收率为88.7%~103.6%,相对标准偏差(RSD, n=6)为1.7%~4.9%,在乳类基质中的加标回收率为88.4%~102.3%, RSD(n=6)为1.2%~3.9%。美白类化妆品常添加防晒剂成分,为监管盲区,采用该方法检测了5批含有防晒剂的美白类化妆品,其所含5种防晒剂的含量为0.8%~5.2%,符合相关要求。该方法操作简单,灵敏度高,回收率好,测定的13种防晒剂均为我国《化妆品安全技术规范》2015版规定的常用的限用组分,可以用于各类化妆品中13种防晒剂的定性定量测定,为市场监管和实验室检测提供新的技术支持。     

Determination of some phthalate acid esters in artificial saliva by gas chromatography-mass spectrometry after activated carbon enrichment

The determination of six phthalate acid esters was achieved in artificial saliva using gas chromatography-mass spectrometry following activated carbon enrichment of samples. Central composite experimental design was applied to optimize method parameters, such as pH, adsorption time and amount of activated carbon. The best compromise of analytical conditions for the simultaneous determination of analytes from spiked artificial saliva were found to be: pH (3), adsorption time (30 min), activated carbon amount (1.8 g L⁻¹) and elution solvent (chloroform). These conditions were applied to study the migration of phthalate acid esters from different children's toys into saliva. A horizontal agitation method was applied to extract the analytes from plastic toys into saliva for 2 h at 37 °C. The detection limits of the method were in the range of 1.3-5.1 μg L⁻¹, while the relative standard deviation (%) values for the analysis of 100 μg L⁻¹ of the analytes were below 3.0% (n = 5). Di-2-ethylhexyl phthalate was the main analyte found in these samples.     

Determination of sorbic acid in urine by gas chromatography-mass spectrometry.

The average daily uptake of the common food preservative sorbic acid is estimated to range from 0.01 to 1.1 mg kg-1. Sorbic acid mainly is metabolised to carbon dioxide. Minor amounts are converted to trans,trans-muconic acid (ttMA) as well as excreted unchanged into the urine. Since urinary ttMA is a biomarker for the occupational and environmental exposure to benzene, there is an additional need for monitoring the uptake of sorbic acid, particularly at low, environmental benzene exposure levels. For this purpose, a simple, robust and rapid method for the determination of sorbic acid in urine at trace levels was developed. After addition of 10 ml of water and 5 ml of 8 M hydrochloric acid to 10 ml of the thawed urine, the sample was water steam distilled using an automated distillation device. A total of 100 ml of the distillate were solid-phase extracted. After washing, the sorbic acid was eluted with 4 ml methanol. The eluate was reduced under a stream of nitrogen to a volume of 300 microliters. After addition of 500 microliters boron trifluoride in methanol and incubation for 1 h at 60 degrees C, the resulting sorbic acid methyl ester was extracted three times with 1 ml heptane. To the combined heptane layers, sorbic acid ethyl ester was added as an internal standard. After reducing to a volume of 100 microliters in a stream of nitrogen, the final analysis was performed by GC-MS using the fragment ions m/z 126 for the analyte and m/z 140 for the internal standard. The limit of detection was 0.7 ng ml-1 urine and the R.S.D. of 69 duplicate determinations was 7.5%. In a controlled, experimental study and in a field study, we were able to show that urinary sorbic acid is a marker for the dietary uptake of sorbic acid and that sorbic acid is converted to ttMA. On average, 0.1% of the dietary sorbic acid is excreted unchanged into the urine. Excretion is complete within 24 h. We found that, on average, 0.23% of the oral dose of sorbic acid is excreted as urinary ttMA. There was a significant correlation between urinary excretions of sorbic acid and ttMA (r = 0.74, n = 69). We conclude that urinary sorbic acid can be used to correct the urinary ttMA level in order to determine the portion related to benzene exposure. This appears to be necessary particularly at low, environmental benzene levels.     

气相色谱-质谱法快速测定牛奶中的三聚氰胺和三聚氰酸

建立了气相色谱-质谱法测定牛奶中三聚氰胺和三聚氰酸含量的分析方法。样品经二乙胺-乙腈-水溶液超声提取,离心,滤液用氮气吹干后加入硅烷化衍生试剂衍生,气相色谱-质谱测定,选择离子模式监测,外标法定量。在0.025～2 mg/kg范围内,目标物的峰面积与其质量浓度的线性关系良好(r>0.98);在0.5,1.0和2.5 mg/kg的添加水平,三聚氰胺和三聚氰酸的平均回收率分别为84%～87%和75%～102%,相对标准偏差(RSD)分别为5.7%～11.7%和4.9%～7.8%;三聚氰胺和三聚氰酸的检出限(LOD)分别为0.05 mg/kg和0.10 mg/kg。结果表明:该方法简便、快速、灵敏、准确,适合牛奶中三聚氰胺和三聚氰酸的确证和定量测定。     

Determination of 4-alkylphenols by novel derivatization and gas chromatography-mass spectrometry

A simple and sensitive method for the determination of alkylphenols in water samples has been developed using gas chromatography-mass spectrometry. Alkylphenols were determined after the extractive derivatization with pentafluoropyridine. The derivatization of alkylphenols efficiently proceeded to give the corresponding 4-tetrafluoropyridyl derivatives under the biphasic reaction system. The derivatization conditions including the phase-transfer catalyst, the amount of pentafluoropyridine, the reaction time, the concentration of NaOH and organic solvent were optimized. On the mass spectra of these derivatives, intense specific ion peaks were observed: m/z 256 for 4-n-alkylphenols and m/z 284 for 4-tert.-alkylphenols. Calibration curves were linear in the range of 20-1000 ng/l (200-10,000 ng/l for nonylphenol), and the detection limits varied between 6.93 and 15.7 ng/l (85.2 ng/l for nonylphenol). The average recoveries of the alkylphenols in a fortified river water sample (100 ng/l except for nonylphenol: 1000 ng/l) ranged from 91.1 to 112%. The relative standard deviations were found to be between 5.6 and 16%. This method was successfully applied to the determination of alkylphenols in river water.     

Determination of iodide by derivatization to 4-iodo-N,N-dimethylaniline and gas chromatography-mass spectrometry

A real-time determination of iodide is proposed which involves the oxidation of iodide with 2-iodosobenzoate in the presence of N,N-dimethylaniline. The reaction is completed within 1 min to yield 4-iodo-N,N-dimethylaniline, which is extracted in cyclohexane and determined by GC-MS. It was also possible to determine iodine by derivatization in the absence of 2-iodosobenzoate, and iodate by its reduction with ascorbic acid to iodide and subsequent derivatization. A rectilinear calibration graph was obtained for 0.02-50 micrograms l-1 iodide with a correlation coefficient of 0.9998. The limit of detection was 8 ng l-1 iodide. The method was applied to the determination of iodate in iodized table salt and free iodide and total iodine in sea-water, and to spiked samples when the recovery was in the range 96.8-104.3% (RSD 1.9-3.6%). A sample clean-up by solid-phase extraction with a LiChrolut EN cartridge is proposed.     

Determination of ink photoinitiators in packaged beverages by gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry

A new analytical method, using gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-mass spectrometry (LC/MS) techniques, was developed for the determination in packaged food beverages of five ink photoinitiator residues: 2-isopropylthioxanthone (ITX), benzophenone, 2-ethylhexyl-4-dimethylaminobenzoate (EHDAB), 1-hydroxycyclohexyl-1-phenyl ketone (IRGACURE 184) and ethyl-4-dimethylaminobenzoate (EDAB). Samples were extracted from selected beverages (milk, fruit juices and wine) and relative packagings, using n-hexane and dichloromethane, respectively, purified on solid-phase extraction (SPE) silica gel cartridges, and then analyzed in GC/MS and LC/MS. The recovery percentages, obtained spiking the beverage samples at concentrations of 4 and 10 microgl(-1) with a standard mixture of photoinitiators, were in the range 42-108% (milk), 50-84% (wine), and 48-109% (fruit juices). The repeatability of the method was assessed in all cases by the % of correlation value, that was lower than 19%. The lowest limits of detection (LODs) and limits of quantification (LOQs), obtained using GC/MS, were in the range 0.2-1 and 1-5 microgl(-1), respectively. The method was applied to the analysis of forty packaged food beverages (milk, fruit juices and wine samples). The most significant contamination was that of benzophenone, found in all samples in a concentration range of 5-217mugl(-1). Its presence was confirmed by an LC/Atmospheric-Pressure PhotoIonization (APPI)/MS/MS analysis. The photoinitiator (EHDAB) was found in eleven out of forty beverages in a concentration range of 0.13-0.8 microgl(-1). Less important was the ITX contamination, found in three out of forty samples in a range 0.2-0.24 microgl(-1). The work proposes a new method to analyze ink photoinitiator residues in polycoupled carton packaging and in contained food beverages.     

Determination of naphthalenesulfonic acid isomers by large-volume on-line derivatization and gas chromatography-mass spectrometry

This work presents a modified method to analyze polar and water-soluble naphthalene monosulfonic acid (NS) isomers in industrial effluents and river water samples. The method involves extraction of samples by a styrene-divinylbenzene copolymer solid-phase extraction cartridge, and on-line derivatization in the GC injection port using a large-volume (10 microl) sample injection with tetrabutylammonium salts. The analytes were then identified and quantitatively determined by GC-MS. The large-volume injection-port derivatization technique provides sensitivity, fast and reproducible results for NS isomers, to quantitation at 0.05 microg/l in 200 ml of water sample. Enhanced extracted mass chromatograms of molecular ion and [M-56]+ ion of butylated NS isomers by electron impact ionization MS allows us to determine residues at trace levels in environmental samples. Recoveries of the NS isomers in spiked water samples ranged from 70 to 82% with RSDs around 10%. Naphthalene-2-sulfonic acid was found as a major pollutant and propagated in surface water and industrial effluents.     

气相色谱-质谱联用法检测母乳脂肪中反式脂肪酸

建立了母乳中反式脂肪酸(TFAs)的气相色谱-质谱(GC-MS)检测方法,并应用于母乳脂肪中TFAs的检测。母乳用氨水水解,乙醚和石油醚提取脂肪,提取的脂肪加入C21: 0内标,用三氟化硼甲醇溶液在80℃水浴中冷凝回流15 min进行甲酯化,正己烷提取,上清液用GC-MS分析,内标法定量。在低、中、高加标水平上验证方法的准确度与精密度,结果显示该方法可用于母乳中18种TFAs及其同分异构体的检测,其中12种TFAs在母乳脂肪中的方法检出限为4.0~47.1 mg/kg,回收率为80%~113%, RSD为2.9%~14.5%(n=6)。TFAs在部分母乳脂样品中检出,含量为9.54~6.9 mg/kg。该方法定性、定量准确,可有效用于母乳中TFAs的检测,但仍存在脂肪酸本底干扰等问题,可结合银离子固相萃取柱预分离技术进一步完善。     

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.     

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。     

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%。     

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.     

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.     

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.     

Determination of amino acid enantiomers in human urine and blood serum by gas chromatography-mass spectrometry

Amino acid (AA) enantiomers were determined as N(O)-pentafluoropropionyl-(2)-propyl esters by chiral gas chromatography-mass spectrometry (GC-MS) in 24 h samples of the urine of three healthy volunteers and in their blood sera. In urine the largest amounts were determined for D-Ser (64-199 micromol/day) and D-Ala (24-138 micromol/day). In blood sera, D-Ala (2.3-4.2 micromol/L) and D-Ser (1.0-2.9 micromol/L) were most abundant. Varying amounts of the D-enantiomers of Thr, Pro, Asx, Glx, Phe, Tyr, Orn and Lys were also found, albeit not in all urines and sera. Further, enantiomers were quantified in urine samples of two volunteers fasting for 115 h. Quantities of renally excreted D-AAs decreased in fasting, although amounts of D-Ser (69 and 77 micromol/L urine) as well as other D-AAs were still detectable. Time-dependent analyses of urine showed that D-AAs are continuously excreted. Copyright -Copyright 2001 John Wiley & Sons, Ltd.