深海鱼油中脂肪酸的柱前衍生-高效液相色谱串联质谱分析

用1-2-(对甲苯磺酸酯)乙基-2-苯基咪唑4,5-f9,10-菲(TSEPIP)作为柱前荧光衍生试剂,在EclipseXDB-C8(4.6×150mm,5μm,Agilent)反相色谱柱上,采用梯度洗脱在检测波长为380nm(激发波长为260nm)的条件下,实现了阿拉斯加深海鱼油中饱和脂肪酸含量的外标法定量测定。26种饱和脂肪酸的线性范围是200.0pmol～48.83fmol,线性相关系数均大于0.9996,检测限为3.824～47.13fmol(信噪比为3:1测得,S/N3:1)。经柱后串联质谱大气压化学电离源(APCI)正离子模式实现了各种饱和与不饱和脂肪酸衍生物的质谱鉴定,进而通过峰面积归一化法得出了所有饱和与不饱和脂肪酸的相对含量。结果表明,深海鱼油主要含有C12～C22的脂肪酸,共鉴定出25种脂肪酸,其中不饱和脂肪酸含量占69.71%(峰面积百分比,下同),特别是具有重要生理作用的多不饱和脂肪酸,如C20:5:5,8,11,14,17-二十碳五烯酸(5,8,11,14,17-eicosapentaenoicacid,EPA,16.62%),C22:6:2,5,8,11,14,17-二十二碳六烯酸(2,5,8,11,14,17-docosahexenoicacid,DHA,12.31%)。     

超高效液相色谱-质谱测定牛乳中游离氨基酸

建立牛乳中未衍生游离氨基酸的超高效液相色谱串联质谱的测定方法。样品采用酸化乙腈沉淀蛋白,正己烷脱脂,氮吹至近干后初始流动相复溶,超声溶解离心过膜后检测。结果显示:在14 min内所分析目标物得到较好的分离,浓度与峰面积的线性关系良好,相关系数在0.991 2~0.999 8之间,回收率在76%~124%,相对标准偏差1.0%~12.9%。     

Determination of 20 Free Amino Acids in Asparagus Tin by High-Performance Liquid Chromatographic Method after Pre-Column Derivatization

A novel method was studied for determination of 20 free amino acids in asparagus tin by high-performance liquid chromatography with pre-column derivatization. Derivatization of the samples was performed with 4-chloro-3,5-dinitrobenzotrifluoride (CNBF), and the SPE cartridge was used for purification and enrichment of the analytes. The derivatization conditions and the influence of elution composition on the separation were investigated. The reaction of amino acids with CNBF was completed in pH 9.0 borate buffer. The separation of amino acids was achieved at room temperature within 60 min by gradient elution mode with triethylamine in mobile phase, and the flow rate is 0.32 mL min⁻¹ constantly. The method correlation coefficient was from 0.9975 to 1.0000 in concentrations ranging from 20 to 2000 μmol L⁻¹, except asparagine (from 100 to 10000 μmol L⁻¹). The detection limits of amino acids were from 1.2 to 6.0 μmol L⁻¹, with a signal-to-noise ratio of three times. The calculated recoveries of the proposed method were from 81.4% to 109.4%, and relative standard deviations were 0.48–3.94% in application to the quantitative determination of free amino acids in asparagus tin samples. The present method is reliable and sensitive that allows fast analysis of free amino acids in asparagus tin, which makes it suitable for further study of free amino acids in other asparagus foods.     

固相萃取－液相色谱－电喷雾串联质谱法测定鲜枣中14种农药残留

选择强疏水性硅胶基质t C18柱为固相萃取净化柱,以电喷雾(ESI)为离子源,正离子多级反应离子监测(MRM)模式,建立了固相萃取-液相色谱-串联质谱法(HPLC-MS/MS)测定鲜枣中14种农药(包括有机磷杀虫剂、杀菌剂,有机杂环类杀虫剂和新型烟碱类杀虫剂)残留的分析方法。研究比较了不同提取溶剂的提取效果和不同固相萃取小柱的净化效果,同时优化了色谱分离条件和质谱条件。14种农药在10~500μg/L(或1~50μg/L)范围内线性相关,相关系数为0.996 3~0.999 9,方法的定量限为0.10~9.50μg/kg。14种农药在鲜枣中3个水平添加质量浓度的的回收率在67.4%~116.8%,RSD为0.8%~14.8%之间。该方法操作简便,灵敏度、准确度和精密度均符合农药多残留检测技术要求,适用于鲜枣中14种农药多残留的检测。     

Determination of Antimicrobial Residues in Honey by Liquid Chromatography Tandem Mass Spectrometry

Antibiotics are generally used worldwide against bacterial diseases in the treatment of food-producing animals. Since the residues of active agents or their metabolites can appear in these foods, the European Union, for instance, has set maximum residue limit concentrations for authorised veterinary drugs in foodstuffs. However, as yet, regulatory limits have not been established for honey and thus far, only recommendations exist. The aim of this study is to present a multiscreening method for residues in honey for the determination of 36 antimicrobial residues associated with several antibiotics of the B1 group (sulfonamides, trimethoprim, aminoglycosides, tetracyclines, quinolones and lincomycin) as well as the antibiotic griseofulvin. During the screening analysis, samples are hydrolysed in an acidified medium, purified on polymeric solid-phase extraction cartridges and subsequently analysed by reversed phase ion pair liquid chromatography tandem mass spectrometry. The liquid chromatographic separation was optimised by computer simulation with DryLab software. The positive identification of target compounds in suspicious samples was confirmed using earlier developed antibiotic class specific methods of which the aminoglycoside method is herein described in detail. The developed approaches were then applied to samples in the national monitoring program after their successful validation. Moreover, the screening and confirmatory methods were applied to proficiency test samples resulting in satisfactory identification and quantification. However, the analysis of real samples revealed that co-eluting target compounds can have considerable influence on the accuracy of this semi-quantitative multiscreening method.     

LC-MS-MS同时定量检测硒蛋氨酸和硒胱氨酸

目的 建立同时测定硒蛋氨酸(SeMet)和硒胱氨酸(SeCys)含量的液相色谱-串联质谱法(LC-MS-MS).方法色谱柱:Waters Symmetry C18(150 mm×3.9 mm,5μm);流动相:甲醇+0.1%七氟丁酸水溶液(35+65),流速为500μl/min;以氮气为碰撞气,利用多反应离子监测方式测定SeMet(MRM m/z 198.1→181.0,198.1→152.0)和SeCys(MRM m/z 337.0→248.0,337.0→88.2)信号.结果 SeCys和SeMet检出限分剐为2.0 ng/ml和0.5 ng/ml;以198.1→181.0为定量分析离子对.SeMet的线性回归方程为:y=707x+990,r=0.999 3;以337.0→248.0为定量分析离子对,SeCys的线性回归方程为:y=64.3x+695,r=0.999 9.结论该方法能够使2种含硒化合物在一次进样中实现完全分离和在线测定.能够满足快速准确检测SeCys和SeMet含量要求.     

HPLC-MS/MS法检测桶装饮用水中壬基酚污染水平

建立高效液相-质谱法(HPLC-MS/MS)检测饮用水中壬基酚的方法,并对天津市桶装水企业从水源、生产、储存到消费全过程中壬基酚的污染水平进行调查。壬基酚的方法检出限为0.1μg/L,加标回收率为86.3%~92.2%,相对标准偏差为3.1%~4.6%。通过对饮用水检测,发现所采集样品企业的水源中壬基酚浓度范围在5.97μg/L~12.40μg/L,表明其水源已受到壬基酚的污染,而盛装容器无壬基酚明显迁移,桶装水的生产环节能有效去除部分壬基酚。     

柱前衍生-超高效液相色谱法同时测定虫草酒中17种游离氨基酸

建立一种快速、灵敏的柱前衍生-超高效液相色谱法同时测定虫草酒中17种游离氨基酸的方法。酒样经氮吹除醇,然后以6-氨基喹啉-N-羟基琥珀酰亚胺基氨基甲酸酯(AQC)为衍生试剂在硼酸盐缓冲溶液中衍生化。色谱柱为Waters Acc Q·Tag TM Ultra C18(1.7μm,2.1×100mm),Acc Q·Tag Ultra Eluent A及Acc Q·Tag Ultra Eluent B梯度洗脱,流速为0.7 m L/min,检测器为二极管阵列检测器,检测波长260nm。结果表明:17种氨基酸在25~400μmol/L内有浓度范围内,峰面积与浓度之间具有良好的线性关系(r2≥0.9950),回收率在83.21%~119.82%。该方法在10min内17种氨基酸能够完全分离,具有准确、快速、重复性好的特点。     

QuEChERS-高效液相色谱串联质谱法测定粮谷中20种真菌毒素

建立了QuEChERS(快速、简单、便宜、有效、可靠、安全)-高效液相色谱串联质谱测定粮谷中20种真菌毒素的检测方法。样品经乙腈-水-甲酸(80∶18∶2)混合溶液提取后,使用无水硫酸镁(MgSO₄)、N-丙基乙二胺(PSA)、十八烷基键合硅胶吸附剂(C18)净化以后,取一定体积上清液在40℃水浴条件下氮吹浓缩至干,使用甲醇-水-甲酸(30∶70∶0.1)混合溶液复溶,真菌毒素目标物经C₁₈色谱柱进行洗脱分离,采用多反应监测模式(MRM)检测,外标法进行结果定量。20种真菌毒素在一定范围内均呈现良好的线性关系(R²>0.99),在低、中、高3个浓度水平的平均回收率为61%～118%,相对标准偏差(RSD)为1%～9%(n=6),检出限为0.17～6.67μg/kg,定量限为0.5～20μg/kg,满足GB/T 27404—2008中对实验室质量控制和食品理化检测的要求。     

高效液相色谱法测定大豆中游离氨基酸含量

以邻苯二甲醛和氯甲酸芴甲酯联合柱前衍生,反相C18短柱分离,二元梯度洗脱,二极管阵列检测器（用于检测胱氨酸和赖氨酸）和荧光检测器（用于检测其他氨基酸）联合检测,建立了反相高效液相色谱法测定大豆种质资源中20种游离氨基酸含量。各氨基酸浓度在5～900μmol／L范围内线性良好,相关系数为0．9991以上。检出限低,灵敏度高。以5％三氯乙酸为提取溶剂,游离氨基酸的提取效果好,标准添加回收率为96．32％～102．25％,相对标准偏差为1．56％～4．30％（n=6）。本方法可用于大豆及其它谷物中游离氨基酸含量的测定。     

超高效液相色谱串联质谱法测定豆类食品中的游离神经递质类氨基酸

本文建立了超高效液相色谱串联三重四极杆质谱(UPLC-MS/MS)测定豆类食品中神经递质类氨基酸的分析方法.样品经超纯水超声提取,Zorbax SB-Aq RRHT色谱柱(3.0 mm×100 mm,1.8μm)分离,以甲醇和0.5 mmol/L乙酸铵溶液为流动相梯度洗脱,流速为0.3 mL/min.采用电喷雾离子源(...     

UPLC-MS-MS检测饮料中的4-甲基咪唑及其同分异构体2-甲基咪唑

建立超高效液相色谱-串联质谱（ultra performance liquid chromatography -tandem mass spectrometry,UPLCMS- MS）法检测饮料中的4-甲基咪唑（4-(5-)-methylimidazole,4-Mel）及2-甲基咪唑（2-methylimidazole,2-Mel） 的方法。以水溶解样品,OASIS®MCX固相萃取柱富集净化后,进入UPLC-MS-MS检测,内标法定量。在优化的条 件下,以ACQUITY UPLC® HILIC色谱柱（2.1 mm×100 mm,1.7 mm）为分析柱,乙腈和5 mmol/L甲酸铵溶液为 流动相,在电喷雾正离子多反应监测模式进行检测。结果表明,4-Mel和2-Mel在9～500 ng/mL范围内线性关系良 好。方法的定量限为3.0 mg/kg。在4 个加标水平下,3 种不同基质饮料中4-Mel和2-Mel的平均回收率分别为97.3% 和93.7%,相对标准偏差分别为3.8%和3.4%,该方法适用于饮料中4-Mel和2-Mel的检测。利用该方法对市售饮料中 4-Mel和2-Mel的含量进行检测,在软饮料、焦糖色饮料及咖啡饮料中检出含有4-Mel或2-Mel;而功能性饮料中未检 出4-Mel和2-Mel。     

Determination of Fatty Acids in Beef by Liquid Chromatography-Electrospray Ionization Tandem Mass Spectrometry

A method was developed to separate, identify, and quantify 28 fatty acids of potential health relevance using liquid chromatography/electrospray ionization-mass spectrometry (LC/ESI-MS). Optimization of the experimental factors enabled baseline separation of the fatty acids including three pairs of closely related fatty acid isomers (C18:3n-3 and C18:3n-6; C18:1 and C18:1 t; and C20:3n-3 and C20:3n-6) that are challenging to separate. The limits of detection ranged from 0.01 to 0.26 mg L^?1 for the 28 fatty acids, and average recovery (mean, n?=?4) was found to be 102?±?12 %. In addition, the proposed method was validated using a quality control standard mix of fatty acids which yielded acceptable precision and accuracy. Fatty acid concentrations in conventional grain-fed and organic grass-fed beef were determined, and the results show that grass-fed beef have a lower omega-6 to omega-3 ratio (1.6–2.8) compared to grain-fed beef (9.3–13.5). Principal component analysis (PCA) was applied on the resulting data to find correlations between significant fatty acid composition and the diet of beef samples.     

液相色谱-串联质谱法测定皮革中PFOS及PFOA盐类

建立了皮革中全氟辛烷磺酸盐(PFOS)及全氟辛酸盐(PFOA)的萃取及液相色谱-串联质谱(LC-MS/MS)的检测方法.采用索氏抽提进行萃取,溶剂为甲醇,萃取液经弱阴离子固相萃取柱(Oasis WAX)净化处理后,采用负离子电喷雾电离、多级反应离子监测(MRM)模式进行LC-MS/MS检测.结果表明,PFOS和PFOA浓度在1 ～50 μg/L范围内,线性相关系良好,相关系数均大于0.995,在10 ～160 mg/kg范围内的添加水平回收率为80%～105%,相对标准偏差为6.3%～15.5%(n=6),定量检出限均为0.5 mg/kg.该方法可用于皮革中PFOS及PFOA盐类物质的测定.     

柱前衍生高效液相色谱法测定贝类产品中氨基酸含量

采用柱前衍生高效液相色谱法,测定了3种贝类中天冬氨酸、赖氨酸、亮氨酸等17种氨基酸含量。衍生试剂为6-氨基喹啉基-N-羟基琥珀酰亚胺基甲酸酯(AQC),流动相为醋酸盐-磷酸盐缓冲溶液、乙睛、水,梯度洗脱。色谱柱为AccQ·Tag(Waters)氨基酸分析柱,紫外检测。结果显示,氨基酸浓度与峰面积呈良好的线性关系,线性范围10～80μmol/L,检出限为0.23μmol/L,相关系数均在0.998以上,相对标准偏差RSD在2.1%～4.8%之间,回收率在91.3%～113.2%之间。     

基于超高效液相色谱-四极杆-静电场轨道阱高分辨质谱快速测定水果中18种游离氨基酸

本文采用超高效液相色谱-四极杆-静电场轨道阱高分辨质谱(UPLC-Q-Exactive Orbitrap)建立了水果中18种游离氨基酸的快速测定方法.水果样品经粉碎、超声提取、离心、过滤后,使用SHISEIDO CAPCELL PAK BB-H C18色谱柱(2.1 mm×150 mm,3 μm)分离,以0.2％甲酸水...     

高效液相色谱-串联质谱法同时测定中草药饮料中11 种有毒生物碱

建立同时测定中草药饮料中11 种有毒生物碱（乌头碱、次乌头碱、新乌头碱、马钱子碱、士的宁、秋水 仙碱、喜树碱、阿托品、东莨菪碱、毛果芸香碱和鬼臼毒素）的高效液相色谱-串联质谱分析方法。试样直接过 0.22 μm滤膜,经Kinetex C18色谱柱（2.1 mm×100 mm,2.6 μm）分离后,在多反应监测模式下定性及定量分析。结 果表明：11 种有毒生物碱在在其线性范围内与其峰面积线性关系良好（＞0.999 0）,方法检出限为0.05～0.5 μg/L, 在低、中、高3 个添加水平范围内的平均回收率为75.0%～88.4%,相对标准偏差均小于7.6%。该方法操作简便、灵 敏度高、重复性好、定性定量准确,适用于中草药饮料中有毒生物碱的测定。     

液相色谱串联质谱法测定烟用香精香料中的亚硝胺

建立了液相色谱串联质谱法(LC-MS/MS)测定烟用香精及料液中N-亚硝基去甲基烟碱(NNN)、N-亚硝基假木贼碱(NAB)、N-亚硝基新烟草碱(NAT)和4-(N-甲基-N-亚硝胺)-1-(3-吡啶基)-丁酮(NNK)4种烟草特有亚硝胺(TSNAs)的方法。样品采用含0.1 mol/L的醋酸铵甲醇水溶液溶解提取,在C18色谱柱上采用梯度洗脱分离目标物和干扰物,电喷雾正离子模式下,多反应检测模式测定。结果表明,4种TSNAs的检测限(S/N=3)和定量限(S/N=10)分别为0.4~1.6 ng/g和1.4~4.8 ng/g,标准工作液在1~50 ng/L的范围内线性良好,相关系数均大于0.9995,高中低三个浓度水平的加标回收率在93.5%~105.9%之间,6次重复实验的RSD范围为1.8%~4.7%,均小于5%。使用该方法分析测定了8个市售烟用香精香料样品,其中3个样品检测到TSNAs。该方法准确、灵敏,适用于烟用香精及料液样品中TSNAs的分析检测。     

异硫氰酸苯酯柱前衍生RP-HPLC法同时测定莲雾中15种游离氨基酸的含量

采用异硫氰酸苯酯(PITC)为柱前衍生化试剂,结合反相高效液相色谱法,建立了同时测定莲雾果实中15种游离氨基酸含量的方法。采用Atlantis T3柱为固定相,以0.1 mol/L乙酸钠缓冲液(pH6.5,含0.5%三乙胺)和乙腈-水(4:1)为流动相进行梯度洗脱,流速为1.0 mL/min,柱温35 ℃,紫外检测器波长254 nm。各氨基酸组分在2.0~500 mg/L范围内具有良好的线性关系,相关系数r均大于0.99,检出限为0.08~0.35 mg/L,定量限为0.35~1.25 mg/L,加标回收率为85.61%~106.68%,相对标准偏差RSD均小于5%。该方法使得15种氨基酸很好的分离,且准确度和精密度好,灵敏度和回收率高,适用于莲雾果实游离氨基酸含量的分析。

     

高效液相色谱-串联质谱法测定保健品中甲壳素

本研究建立了保健品中甲壳素的高效液相色谱-串联质谱(HPLC-MS/MS)测定方法。含甲壳素保健品样品经盐酸水解后生成氨基葡萄糖,吸取上清液过OASIS MCX固相萃取小柱,用水淋洗固相萃取柱并弃去全部流出液,用真空泵抽干小柱,再用5%氨水甲醇洗脱被测物,洗脱液于60℃水浴中氮气吹干,用初始流动相定容,以C18色谱柱和乙腈-0.1%甲酸水流动相体系进行梯度洗脱分离,采用电喷雾负离子多反应监测(MRM)模式测定。实验考察优化了水解条件、净化条件和仪器条件。在优化实验条件下,甲壳素水解产物在0.1~50 mg/L浓度范围内线性关系良好,相关系数为0.9907;甲壳素的方法检出限(S/N=3)为1.5μg/g,方法定量限(S/N=10)为6.25μg/g;平均加标回收率为89.2%~92.4%,相对标准偏差(n=6)为0.25%~1.35%。该方法前处理简单、灵敏度高、选择性强、回收率高、精密度好,适用于保健品中甲壳素的测定。