气相色谱-质谱法测定食品中邻苯二甲酸酯

提出了气相色谱-质谱法测定食品中16种邻苯二甲酸酯(PAE′s)含量的方法。详细叙述了不同基质的食品的处理方法,高脂类样品需经凝胶渗透色谱净化。采用HP-5MS石英毛细管柱进行分离和电子轰击离子源质谱检测。16种PAE′s的线性范围为0.50～20.0mg·L-1,检出限(3S/N)在6.03～826μg·kg-1之间。在1,10mg·kg-1两个浓度水平进行加标回收试验,纯油脂和高脂固体样品中16种PAE′s的平均回收率分别在79.2%～101%和77.8%～97.4%之间,测定值的相对标准偏差(n=6)分别在3.4%～6.9%和4.1%～6.0%之间。     

液相色谱-串联质谱法测定化妆品中9种禁用芳香胺

应用液相色谱-串联质谱法测定化妆品中联苯胺、4,4′-二氨基二苯醚、邻氨基甲苯醚、3,3′-二甲基联苯胺、2,4,5-三甲基苯胺、4,4′-二氨基二苯硫醚、5-硝基-邻甲苯胺、3,3′-二氯联苯胺、4-氨基偶氮苯等9种禁用芳香胺的含量。样品经1%(φ)三氯乙酸溶液和乙腈提取,分取部分上清液经固相萃取小柱净化。所得净化液以C18色谱柱(50mm×4.6mm,1.8μm)为分离柱,以不同体积比的0.05%(φ)甲酸溶液和含0.05%(φ)甲酸的乙腈的混合液为流动相进行梯度洗脱,采用电喷雾正离子源多反应监测模式检测。3,3′-二氯联苯胺的线性范围为0.5~50mg·kg-1,检出限(3S/N)为0.15mg·kg-1。其余8种芳香胺的线性范围均为0.2~50mg·kg-1,检出限(3S/N)均为0.05mg·kg-1。加标回收率在78.3%~103%之间,测定值的相对标准偏差(n=6)均小于6.0%。     

二环己胺中微量苯胺等杂质的气相色谱与气-质联用分析

二环己胺可由苯胺催化加氢制得,故产物中有苯胺等杂质存在。苯胺等杂质对二环己胺产品质量有严重的影响,因此二环己胺纯度需达到99．5％以上,苯胺的含量应低于0．1％。本文以苯甲醇为内标,建立了二环己胺产品中微量苯胺的气相色谱分析条件,并且采用气相色谱一质谱(GCMS)分析了各杂质峰的归属,发现二环己胺产品纯度达不到     

液相色谱-串联质谱法测定葡萄酒中7种生物胺含量

提出了液相色谱-串联质谱法测定葡萄酒中2-苯乙胺、色胺、尸胺、组胺、腐胺、精胺、亚精胺等7种生物胺含量的方法。样品经0.45μm滤膜过滤后,直接通过Zorbax Eclipse XDB C8色谱柱(4.6mm×150mm,5μm)进行分离,以不同体积5mmol·L-1乙酸铵-10mmol·L-1全氟己酸甲醇溶液(A)和5mmol·L-1乙酸铵-10mmol·L-1全氟己酸水溶液(B)的混合液为流动相梯度洗脱,串联质谱法进行测定。7种生物胺的质量浓度均在0.1～5.0mg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)在0.005～0.02mg·L-1之间。以空白葡萄酒样品为基体进行加标回收试验,测得回收率在84.1%～97.5%之间;测定值的相对标准偏差(n=5)在6.3%～13%之间。     

官能团化聚己内酯的合成与表征

通过分子结构设计合成了新型含有侧基官能团的聚己内酯材料.首先,通过亲核加成反应,由溴乙酸乙酯与烯胺合成2-乙氧甲酰甲基环己酮;然后以间氯过氧化苯甲酸为氧化剂,通过Baeyer-Villiger氧化反应,得到带有官能团的己内酯单体,6-乙氧甲酰甲基-ε-己内酯;该单体在异辛酸亚锡(Sn(Oct)2)的催化下,本体开环聚合得到相应的均聚物及其与ε-己内酯的共聚物.采用1H-NMR、13C-NMR、GPC和DSC表征了聚合物的结构和热力学性能.随着6-乙氧甲酰甲基-ε-己内酯在共聚物中的含量增加,共聚物的分子量降低,同时熔点和熔融焓也随之降低.     

气相色谱法分析甘蓝及其土壤中的烯啶虫胺残留

建立了气相色谱测定甘蓝植株和土壤中烯啶虫胺残留量的分析方法。样品采用丙酮-水(4:1, v/v)进行提取,经弗罗里硅土柱净化,用电子捕获检测器进行测定。实验结果表明,添加水平为0.02～2.00 mg/kg时,烯啶虫胺在甘蓝植株和土壤中的平均回收率分别为88.73%～94.13%和90.82%～96.27%,相对标准偏差分别为3.09%～7.39%和2.01%～4.92%;方法的最低检出限为0.02 mg/kg。该方法快速简便、灵敏度高、重现性好,可用于环境系统中烯啶虫胺残留量的检测分析。     

液相色谱-串联质谱法测定发酵肉制品中5种生物胺的含量

提出了液相色谱-串联质谱法测定发酵肉制品中组胺、酪胺、腐胺、尸胺和色胺等5种生物胺含量的方法。1.00 g样品经5%(体积分数)高氯酸溶液20 mL提取2次,合并上清液,用400 g·L^-1氢氧化钠溶液调节上述上清液pH至2～3,用0.5%(体积分数,下同)高氯酸溶液定容至50 mL。取2 mL上述溶液,与2 mL 0.5%高氯酸溶液混匀,经正己烷5 mL净化2次。取上述溶液0.25 mL,用乙腈定容至1.00 mL,过滤。以Waters Atlantic^? HILIC Silica色谱柱为固定相,以含10 mmol·L^-1甲酸铵的0.5%(体积分数,下同)甲酸溶液-含10 mmol·L^-1甲酸铵、0.5%甲酸的乙腈溶液为流动相进行梯度洗脱,采用液相色谱-串联质谱法测定滤液中5种生物胺的含量。结果表明：5种生物胺的质量浓度在一定范围内与对应的峰面积呈线性关系,检出限(3S/N)为0.010～0.80 mg·kg^-1。按标准加入法进行回收试验,回收率为82.0%～120%,测定值...     

大鼠尿液与粪便中氟噻草胺的UPLC-MS/MS法测定

建立了一种测定大鼠尿液和粪便中氟噻草胺含量的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。粪便与尿液样品采用乙腈提取;液相色谱分离采用Phenomenex反向C18色谱柱(50 mm×4. 6 mm,5μm),以0. 1%甲酸水和乙腈为流动相,流速0. 6 m L/min;质谱检测采用电喷雾离子源,正离子模式和多反应监测(MRM)方式进行扫描。结果表明:氟噻草胺在尿液(0. 10～10. 0 mg/L)和粪便(0. 25～50. 0 mg/L)中线性关系良好,相关系数r 0. 99,尿液和粪便中氟噻草胺的定量下限分别为0. 10 mg/L和0. 25 mg/L;质控样品的日内与日间相对标准偏差不大于9. 9%。样品稳定性为93. 7%～108%,尿中平均提取回收率为97. 0%～98. 8%,基质效应为98. 8%～107%,均符合生物分析方法验证的要求。考察了大鼠单次灌胃给予氟噻草胺400 mg/kg后的排泄动力学,144 h内尿液与粪便的总累积排泄率为12. 62%,其中尿中的累积排泄率为1. 12%,粪便中的累积排泄率为10. 13%,表明氟噻草胺主要经粪便排泄。该法灵敏、专属、准确,可用于大鼠尿液、粪便中氟噻草胺浓度的测定。     

胺桥杯［4］芳烃固相微萃取探头的特性及其应用

采用溶胶-凝胶方法制备了25,27-二羟基-26,28-(1′,10′-二氧代-4′,7′-二氮杂-3′,8′-二氧代亚辛基)-对-特丁基-杯［4］芳烃/羟基硅油(胺桥杯［4］/OH-TSO)固相微萃取(SPME)探头,通过对脂肪胺和芳胺的分析研究了它的特性。该探头具有耐高温、抗溶剂冲洗、使用寿命长、重现性好等特点。杯环上极性胺桥的引入增强了涂层的极性,因而在不需衍生的情况下对脂肪胺和芳胺都具有很好的萃取能力,表现出对胺类化合物的特殊选择性。脂肪胺的检出限为0.19～39.51 μg/L,线性范围达3个数     

气相色谱-质谱法同时测定塑料食品接触材料中25种芳香族伯胺的迁移量

采用固相萃取前处理技术,结合气相色谱-质谱法对食品接触材料中25种芳香族伯胺的迁移量进行了同时测定。样品中25种目标物分别用蒸馏水和30 g/L醋酸浸出后,用氨水调节浸泡液至pH 8～10,经固相萃取小柱富集净化,再用体积比为1:1的叔丁基甲醚和乙醇混合液洗脱定容后用气相色谱-质谱仪测定。不同芳香族伯胺的检出限略有差异,在0.4～2.0 μg/kg的范围内。加标水平在10 μg/kg时,除2,4-二氨基苯甲醚在酸性模拟物中的回收率较低外,其他芳香族伯胺的回收率均在51.6%～118.4%之间,相对标准偏差(n=7)为0.5%～9.8%。同时探讨了不同实验条件如叔丁基甲醚和乙醇的体积比、pH值等条件对25种芳香族伯胺回收率的影响。结果表明,该方法准确、稳定,完全满足欧盟指令No 10/2011对食品接触塑料材料及制品中芳香族伯胺特定迁移量的限量要求,可用于食品接触材料中芳香族伯胺的实际检验。     

大孔径毛细管气相色谱法快速测定饮料中的氯胺酮

采用固相萃取技术 ,以二十二烷为内标 ,FID检测器 ,建立了一种测定饮料中的氯胺酮的大孔径毛细管气相色谱新方法 .测定结果表明氯胺酮的线性范围为 0 0 2mg/L - 6 4mg/L ,其最低检测浓度为 0 0 2mg/L ,相对标准偏差为 2 6 % ,平均回收率为 85 6 % .该法简便 ,准确 ,重现性好 ,结果令人满意     

气相色谱法直接测定植物生长素

 建立了一种采用 5 3 0 μm大口径毛细管色谱柱、不经衍生化处理而直接测定吲哚乙酸 (IAA)、吲哚丁酸(IBA)和萘乙酸 (NAA)等植物生长素的气相色谱分析方法。以邻苯二甲酸二丁酯为内标物 ,用 FID检测 ,IAA,IBA和 NAA的相对标准偏差分别为 1 .1 4% ,0 .61 %和 0 .78%。方法简便、快速、准确、重现性好 ,可用于生长素类单组分和混合制剂的质量检测。     

气相色谱法快速测定家用气雾杀虫剂中丙烯菊酯、氯菊酯、增效醚含量

用气相色谱法定量测定了家用气雾杀虫剂中的丙烯菊酯、氯菊酯和增效醚。色谱柱为５％ＱＦ－１／Ｃｈｒｏ－ｍｏｓｏｒｂＷＨＰ,以邻苯二甲酸二苯酯为内标物,测得的回收率分别为１００％,１０２％,９９．９％;变异系数为０．１３,０．５６,０．４８,方法简便、快速、准确。     

气相色谱法分离和测定3种植物内源激素

 应用大口径毛细管气相色谱法,以正二十二烷为内标物,对植物组织中的吲哚乙酸(IAA)、脱落酸(ABA)和赤霉素(GA)等3种内源激素进行了测定。结果表明:IAA,ABA和GA的最低检测限依次为0.16,0.08和0.48mgL,相对标准偏差均小于3.0%,平均回收率为88.4%～92.2%。方法简便、灵敏、准确、重现性好。     

气相色谱法分析季戊四醇的一溴代、二溴代产物

 采用BPX 70毛细管色谱柱对季戊四醇的一溴代、二溴代和三溴代产物进行了分离 ,并对一溴代物、二溴代物进行了定量分析。方法快速、简便、准确度高。     

气相色谱法测定胰酶中的丙酮溶剂残留量

采用气相色谱测定了胰酶中残留的丙酮溶剂,并通过外标法定量分析其含量。气相色谱条件为:氢火焰离子化检测器(FID),DMF作为溶剂,DM-WAX色谱柱(30 m×0.53 mm×1μm),载气为氮气,进样口温度为200℃,检测器温度为300℃,柱温采取程序升温。气相色谱法检测丙酮的加标回收率为92.5%～98.0%,检出限(3S/D)为0.05μg/mL。     

Simultaneous determination of pseudoephedrine hydrochloride and diphenhydramine hydrochloride in cough syrup by gas chromatography (GC)

A simple, rapid and precise gas chromatographic method has been developed for the simultaneous determination of pseudoephedrine hydrochloride and diphenhydramine hydrochloride in cough syrup, using a SS column of 10% OV 1 on chromosorb W-HP (80-100 mesh) and nitrogen as a carrier gas at a flow rate of 30 ml min(-1). The oven temperature was programmed at 135 degrees C for 1 min, with a rise of 10 degrees C min(-1) up to 250 degrees C (held for 5 min). The injector and detector port temperatures were maintained at 280 degrees C. Detection was carried out using Flame ionization detector. Guaphenesin was used as an internal standard. Results of assay and recovery studies were statistically evaluated for its accuracy and precision.     

Candidate EPA, NIOSH method for determining carbon disulfide in air with capillary gas chromatography by orthogonal design

This paper describes a candidate NIOSH EPA method for the determination of carbon disulfide in the air of workplaces with capillary gas chromatography using an orthogonal design. This method is designed to replace the packed column of the NIOSH method with a capillary column. The first part of this work concerned the setup of the method, particularly the choice of chromatographic parameters and finding their main favorable working ranges. The second part, using the statistical method orthogonal design, focused on optimizing the GC conditions, which were: column temperature, T(c) = 90 degrees C; injector temperature, T(i) = 140 degrees C; U section detector temperature, FPDU = 160 degrees C; L section detector temperature, FPDL = 210 degrees C; flow rate of carrier gas, F(c) = 20 cm/s; split ratio = 1/70; and injection volume = 1 microL. The quality control test showed that the coefficient of intra-day variation (CV) was 2.21%. A good logarithm linear correlation between the standard solutions and their peak areas was obtained. In general, the method reported here seems a valid candidate for a NIOSH EPA method due to its high precision and accuracy.     

Improved gas chromatographic method for the determination of the individual free fatty acids in cheese using a capillary column and a PTV injector

Summary A gas chromatographic method with a capillary column and a programmed temperature vaporizer injector has been used to analyze the individual free fatty acids in cheese. The lipids were extracted from an acidified cheese slurry with diethyl ether and treated with tetramethylamonium hydroxide (TMAH) to convert the free fatty acids to tetramethylammonium soaps (TMA-soaps), which were subsequently pyrolyzed to methyl esters in the injector. Carrying out injection at the initial column temperature resulted in lower dispersion of the results, but the solvent front prevented quantitative determination of butyric and caproic acids, and an injector temperature of 300°C was therefore employed. Under the conditions tested, trimethylamine (tma) flash-off did not affect the determinations. The accuracy of the method improved at higher free fatty acid contents (coefficient of variation of 0.53% for a total free fatty acid content of 9000 mg/kg as opposed to 7.0% for a total free fatty acid content of 1400 mg/kg). The recovery rate for individual free fatty acids ranged between 91 and 103%.     

Simultaneous quantification of total medium- and long-chain fatty acids in human milk by capillary gas chromatography with split injection

Four different quantification methods for the capillary gas chromatographic determination of medium-chain fatty acids (6:0-12:0) and myristic acid in human milk samples, using a split injector, were compared. Odd-carbon-numbered fatty acids (5:0-17:0) were added as internal standards. Each medium-chain fatty acid and myristic acid was calculated on the basis of: the peak area of the internal standard with one methylene group less; the peak area of the internal standard with one methylene group more; half the sum of the peak areas of the internal standards with one methylene group less and more (bracketting method); the peak area of 17:0. The peak-area ratio of each analyte and 17:0 in a standard was found to be subject to an unacceptably high coefficient of variation. From the methods using internal standards with one methylene group more and less, the bracketting method was found to be the best, resulting in recoveries close to 100%, with the lowest coefficients of variation. The method was applied for the determination of the fatty acid composition of mature milk samples of 47 Cura?aoan women.