液相色谱串联质谱法测定食品中甘露糖醇、麦芽糖、木糖醇、山梨糖醇

天然甜味剂是从天然植物中提取出来的,在安全性和营养功能方面远好于人工合成的甜味剂.本文采用液相色谱串联质谱法测定了食品中甘露糖醇、麦芽糖、木糖醇、山梨糖醇的残留量,并采用选择离子检测进行阳性确证.液体试样用水超声提取,离心定容后,固体和半固体样品采用水溶解定容,再经固相萃取柱净化,样液经洗脱定容后,供液相色谱-质谱/质谱仪测定,外标法定量.本方法的最低检出限、线性范围和方法回收率分别为:0.10mg/kg、0.10～1000.0mg/kg和89.0～94.9％.本研究建立了食品中甘露糖醇、麦芽糖、木糖醇、山梨糖醇的检测方法,可以快速、灵敏、一次同时测定多个、多类别天然甜味剂及其阳性确证.也为打破国外技术性贸易壁垒、增强我国出口产品在国际市场竞争力提供了有力的保障.     

大气压化学电离-液相色谱串联质谱法测定油基食品中的18种邻苯二甲酸酯类化合物

根据2011年6月卫生部公示的食品中17种禁用邻苯二甲酸酯的名单,本方法采用相色谱-串联四极杆质谱建立了快速测定含油食品中18种邻苯二甲酸酯（PAEs）含量的分析方法。食品采用乙腈提取,加入水稀释后,正己烷液液萃取,样液浓缩至干后,甲醇定容。采用C18液相色谱柱分别在等度与梯度两种洗脱程序下分离,大气压化学正离子电离,多反应监测模式测定。在该优化方法条件下,18种邻苯二甲酸酯检测限（LOQ）在0.05~0.5 mg/kg之间,方法回收率为53.4%~107.9%,相对标准偏差（RSD）为7.2%~24.6%。应用本方法分析了植物油、起酥油、辣椒酱、豆辨酱、饼干等多种食品中18种邻苯二甲酯类物质含量,经与标准方法相比,表明本方法操作简单、测定结果准确,可以作为食品中18种邻苯二甲酸酯类化合物的确证方法。     

硝基呋喃类药物及其代谢产物残留检测技术研究进展

介绍了硝基呋喃类抗生素原药及代谢产物的相关性质,详细阐述了其在食源性动物组织中残留的各类检测技术的原理、特点及研究进展,旨在促进硝基呋喃类药物及其代谢产物常规检测技术的发展。     

Dynamics of microcystin production and quantification of potentially toxigenic Microcystis sp. using real-time PCR

Cyanobacterial blooms in eutrophied water body are generally composed of various genotypes with or without microcystin-producing genes (mcy gene cluster). Thus there is a need for quantification of potent toxin producing strains. The present study aimed at identifying microcystin variants and its producer strains in Durgakund pond, Varanasi, India, based on quantification of cpcBA-IGS and mcyA (condensation domain) genes using real-time PCR and LC-MS. Increase in microcystin concentrations was correlated with increase in mcyA copy number and the level of pigments (chlorophyll a, phycocyanin and carotenoids). Also, selected environmental factors (water temperature, light irradiance, rainfall, pH, N and P) and the concentration of microcystin variants (MC-LR, -RR and -YR) were also assessed in samples during May 2010 to April 2011 to establish the possible correlation among these parameters. Nutrients favored cyanobacterial bloom but it could not be correlated with the levels of microcystin variants and seemed to be geographically specific. Microcystis sp. dominant in the pond comprised potentially toxigenic cells. The ratio of potentially toxigenic Microcystis sp. to that of total Microcystis sp. ranged from 0% to 14%. Such studies paved the way to identify and quantify the most potent microcystin producer in the tropical aquatic body.     

LC-MS/MS测定鞋材中的全氟辛烷磺酸盐

建立了纺织品和皮革样品中全氟辛烷磺酸盐(PFOS)的提取方法,样品用甲醇或乙腈超声提取,提取液经C18柱净化,去除基质干扰后用液相色谱-质谱/质谱联用法(LC-MS/MS)检测,标准曲线线性良好,相关系数r=0.9996,灵敏度高,若是刮表层的检出限为0.4μg/m2,若是称重的检出限为0.02 mg/kg,回收率达78%～89%.     

LC-MS/MS测定肠衣中7种大环内酯类抗生素残留量

建立猪肠衣中螺旋霉素、替米考星、竹桃霉素、泰乐菌素、红霉素、罗红霉素、交沙霉素等7种大环内酯类抗生素残留量的液相色谱-串联质谱测定方法(LC/MS/MS).样品用甲醇提取,Oasis( HLB)固相萃取柱净化,液相色谱-串联质谱测定,外标峰面积法定量.方法的回收率范围为70.9 ％～98.4％;相对标准偏差5.8 ％～17.8％,7种大环内酯类抗生素的检出限均为20 μg/kg.     

液相色谱-串联质谱法检测速冻调制肉制品中糖皮质激素类药物残留

建立液相色谱-串联质谱法检测速冻调制肉制品中糖皮质激素类药物残留的方法。样品经乙酸乙酯提取后,过Silica固相萃取柱净化,最后用乙腈定容,经液相色谱-串联质谱仪测定。样品采用外标峰面积法进行定量,该方法的最小检出限量分别为0.2、0.5、1.0μg/kg,定量限分别为0.5、1.0、2.0μg/kg,添加回收率范围为85.0%～96.4%,RSD为2.3%～6.1%。     

Screening of veterinary drug residues in food by LC-MS/MS. Background and challenges

Regulatory agencies and government authorities have established maximum residue limits (MRL) in various food matrices of animal origin for supporting governments and food operators in the monitoring of veterinary drug residues in the food chain, and ultimately in the consumer’s plate. Today, about 200 veterinary drug residues from several families, mainly with antibiotic, antiparasitic or antiinflammatory activities, are regulated in a variety of food matrices such as milk, meat or egg. This article provides a review of the regulatory framework in milk and muscle including data from Codex Alimentarius, Europe, the U.S.A., Canada and China for about 220 veterinary drugs. The article also provides a comprehensive overview of the challenge for food control, and emphasizes the pivotal role of liquid chromatography-mass spectrometry (LC-MS), either in tandem with quadrupoles (LC-MS/MS) or high resolution MS (LC-HRMS), for ensuring an adequate consumer protection combined with an affordable cost. The capability of a streamlined LC-MS/MS platform for screening 152 veterinary drug residues in a broad range of raw materials and finished products is highlighted in a production line perspective. The rationale for a suite of four methods intended to achieve appropriate performance in terms of scope and sensitivity is presented. Overall, the platform encompasses one stream for the determination of 105 compounds in a run (based on acidic QuEChERS-like), plus two streams for 23 β-lactams (alkaline QuEChERS-like) and 10 tetracyclines (low-temperature partitioning), respectively, and a dedicated stream for 14 aminoglycosides (molecularly-imprinted polymer).     

养殖水产品中孔雀石绿、结晶紫及其代谢产物的前处理方法研究

根据SN/T 1768-2006、GB/T 19857-2005、GB/T 20361-2006标准,比较适合以上标准的3种水产品前处理方法,即:固相萃取法、旋转蒸发法、氮气吹干法.采用液相色谱串联质谱(LC-MS)检测水产品中孔雀石绿(MG)、结晶紫(CV)含量.以3种前处理方法所得回收率为指标,确定固相萃取法为适合的方法.换用不同的固相萃取小柱,对固相萃取法进行优化,以获得最大回收率.结果表明固相萃取小柱LH的最佳回收率超过88％,该固相小柱的重复使用回收率损失仅3％.该方法简便、快速、灵敏,适于水产品中孔雀石绿及其代谢物隐色孔雀石绿,结晶紫及其代谢物隐色结晶紫残留量的检测.     

酶联免疫法与LC-MS/MS法测定水产品中呋喃唑酮代谢物

运用酶联免疫法和LC-MS/MS法对水产品中呋喃唑酮代谢物残留进行测定.样品经2-硝基苯甲醛衍生化并用乙酸乙酯提取.向样品中分别添加0.60、2.00、6.00μ g/kg三个浓度水平的呋喃唑酮代谢物时,酶联免疫法平均回收率分别为99.2%、96.0%和100.0%,变异系数(RSD)为1.8%～12.6%,最低检测限为0.3μg/kg.LC-MS/MS法平均回收率分别为90.8%、94.3%和86.3%,RSD为6.2%～14.3%,最低检测限为0.1μg/kg.用酶联免疫法对150个样品进行检测,筛选出3个阳性样品,经LC-MS/MS确证为阳性,未发现假阳性样品,且测定结果基本一致.研究表明酶联免疫法重复性较好、准确度较高,是一种水产品中呋喃唑酮代谢物残留的快速筛选方法;液- 质/质联用法灵敏度高,适用于阳性样品的确证和精确定量.