砷含量测定在蜂蜜掺假鉴别中的应用

目的建立一种通过检测蜂蜜中砷的含量来鉴别大米糖浆掺假的方法。方法检测并比较大量不同来源的大米糖浆和纯正蜂蜜中砷的含量,同时优化了蜂蜜中砷的检测方法,样品以硝酸-微波消解,电感耦合等离子体质谱(ICP-MS)测定,内标法定量。结果在0~5.0μg/L范围内线性良好,定量限为10μg/kg,10、15和30μg/kg的添加水平的回收率均在83.7%~109.6%之间,相对标准偏差小于5.9%,并确定了蜂蜜中大米糖浆的阳性判定限,砷含量在15μg/kg以上的蜂蜜为大米糖浆掺假蜂蜜。结论该方法前处理简单,结果准确度和精密度高,纯蜂蜜和大米糖浆的中砷的含量差别明显,可用于蜂蜜中大米糖浆的掺假鉴别。     

新疆薰衣草蜜活性成分的分析

以薰衣草蜜、洋槐蜜和椴树蜜3种蜂蜜为材料,对蜂蜜中的还原糖含量、淀粉酶值、蛋白质含量、总酚酸含量和它们清除DPPH自由基的能力进行分析。结果表明:薰衣草蜜中的淀粉酶值、总酚酸含量、蛋白质的含量分别为14.8mL/g·h、(200.8±6.9)μg/g和(25.35±2.74)mg/100g,均高于其他2种蜜,但还原糖含量比其他2种蜂蜜略低,为74%。3种蜂蜜均具有抗氧化的作用,薰衣草蜜与椴树蜜对DPPH自由基的清除能力相当,均高于洋槐蜜。总酚酸含量与抗氧化能力之间无明显相关性,说明蜂蜜中还含有其他的抗氧化活性成分。     

全自动固相萃取结合UPLC-MS/MS同时测定蜂蜜中26种内源性组分

采用全自动固相萃取-超高效液相色谱-串联质谱(ultra-high performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)法同时测定荆条蜜、油菜蜜、洋槐蜜中脱落酸、酚酸和黄酮类等26种内源性组分。样品用磷酸盐缓冲溶液提取,经HLB固相萃取柱净化,用Agilent Eclipse Plus RRHD C₁₈柱(2.1 mm×100 mm,1.8μm)分离,以0.03%甲酸溶液-乙腈为流动相进行梯度洗脱。在电喷雾离子源负离子模式下,结合动态多反应监测模式,外标法定量。26种待测组分在各自的质量浓度范围内均呈良好线性关系,相关系数(r²)均大于0.996,检出限和定量限范围分别为1.0～10.0μg/kg和2.5～25.0μg/kg,在各加标水平,平均回收率为81.9%～101%,相对标准偏差为3.4%～9.8%。UPLC-MS/MS是一种高效、快捷、精准的内源性组分含量的定量分析方法,可为蜂蜜品质控制和鉴别提供技术支持。     

蜂蜜中氨基脲本底来源研究

目的建立液相色谱-串联质谱法测定蜂蜜中的氨基脲本底来源的分析方法。方法采用氨基脲非衍生检测方法和蜂蜜中呋喃类药物代谢物测定法,分别对包装垫圈及模拟性实验中蜂蜜的氨基脲含量进行测定。结果蜂蜜包装垫圈中检测出氨基脲,其含量范围25～3108.9μg/kg;进行模拟性实验的蜂蜜中氨基脲含量明显升高,最大升高含量为38.8μg/kg。结论蜂蜜中氨基脲本底来源与其商品包装材料中内溶物的扩散溶出有关。     

茚三酮法测定蜂蜜及果葡糖浆中的氨基酸含量

蜂蜜是以葡萄糖和果糖为主要成分的天然保健品。果葡糖浆具有和蜂蜜相似的糖类成分,依据糖含量及感官指标很难区别蜂蜜和果葡糖浆。本文根据蜂蜜及果葡糖浆中的氨基酸含量差异,采用茚三酮显色法检测5种蜂蜜、13种果葡糖浆及蜂蜜与果葡糖浆混合物的氨基酸含量,建立快速评价蜂蜜品质的新方法。测定结果表明,茚三酮法测定氨基酸含量具有良好的线性(R2=0.9992),准确性(回收率96.3%～101.1%)和重复性(标准偏差0.8%～5.8%)。5种蜂蜜中氨基酸含量均高于200μg/g,而13种果葡糖浆中氨基酸的含量介于10.1～47.8μg/g之间;蜂蜜和果葡糖浆混合物中氨基酸含量随果葡糖浆掺入量的增加而线性减少,这说明可通过茚三酮法检测蜂蜜中的氨基酸含量,实现蜂蜜品质的快速评价。     

鹅掌柴蜂蜜的糖类指纹图谱构建及掺假识别研究

以鹅掌柴蜂蜜为研究对象,对鹅掌柴蜂蜜、常见掺假物质和掺假蜂蜜的果糖、葡萄糖、蔗糖和麦芽糖的含量进行检测和分析;绘制以果糖含量为X轴,麦芽糖含量为Y轴与果葡糖浆、玉米糖浆、麦芽糖浆含量的等值线图;建立鹅掌柴蜂蜜标准糖类指纹图谱,同时对常见掺假物质及掺假蜂蜜的相似度及99%置信区间进行分析。结果显示,当掺假物质为果葡糖浆时,葡萄糖、果糖和蔗糖的变化不差异性不大,当掺假物质为玉米糖浆和麦芽糖浆时,果糖和葡萄糖的含量随着掺假量的增加而减少,麦芽糖含量随着掺假量的增加而增加,蔗糖含量均为未检出;掺假物质与果糖、麦芽糖的等值线图直观地呈现出鹅掌柴蜂蜜掺假玉米糖浆、麦芽糖浆的分布,可以定量鉴别鹅掌柴蜂蜜掺假情况;鹅掌柴蜂蜜之间的相似度均大于0.999,说明标准糖类指纹图谱能够反映鹅掌柴蜂蜜的共同特性,同时也能够反映掺假蜂蜜与鹅掌柴蜂蜜之间的差异;计算出鹅掌柴蜂蜜中果糖、葡萄糖、蔗糖和麦芽糖含量99%置信区间,果糖的含量范围为42.27 g/100 g~47.79 g/100 g,葡萄糖的含量范围为21.56 g/100 g~27.53 g/100 g,蔗糖为未检出,麦芽糖为0.92 g/100 g~1.55 g/100 g,研究结果可以为蜂蜜的产品质量控制和掺假检测提供理论依据。     

蜂蜜中原蜜黄酮类化合物HPLC图谱比较分析

利用高效液相色谱比较分析不同蜂种、不同产地、加工与否以及不同蜜源蜂蜜中原蜜黄酮类化合物的种类及含量差异。结果表明,意大利蜜蜂油菜原蜜和中华蜜蜂油菜原蜜总峰数和峰形都比较相似,意大利蜜蜂油菜原蜜的总黄酮含量比中华蜜蜂油菜原蜜总黄酮含量高。不同产地的意大利蜜蜂油菜原蜜的图谱峰形整体相似,总黄酮含量和黄酮类化合物种类大致相同。加工后的商品蜜总黄酮含量减少,黄酮类化合物的种类也减少,商品蜜的高效液相色谱图显示其黄酮类化合物的出峰时间靠前,主要密集分布在水溶性的分离相中。3个不同蜜源蜂蜜原蜜黄酮类化合物高效液相色谱图的总峰数和峰形都有较大差异,油菜原蜜、洋槐原蜜及柑橘原蜜的总峰数分别为65、58、70个,柑橘原蜜的总黄酮含量最高,达161.62μg/100 g。单花蜂蜜原蜜黄酮类化合物的高效液相色谱图峰形具有一定的特异性,可以作为指纹图谱用于蜂蜜蜜源的鉴定。     

HPLC法测定铁皮石斛中酚酸类物质组成及含量

针对10份不同产地的铁皮石斛,采用甲醇超声萃取,Oasis HLB固相萃取柱净化,Hypersil BDS C_(18)色谱柱分离,二极管列阵检测器测定,建立高效液相色谱法(high performance liquid chromatography,HPLC)同时测定13种酚酸类物质的检测方法。结果表明:在0.5μg/mL~50.0μg/mL范围内,具有良好的线性关系(R~2≥0.999 6);LOD在0.07 mg/kg~0.3 mg/kg之间;LOQ在0.2 mg/kg~1.0 mg/kg之间;加标回收率在86.7%~102.3%之间,RSD在1.1%~3.5%之间;铁皮石斛中共检出12种酚酸,阿魏酸含量最高,其次是丁香酸、二氢阿魏酰酪胺、对羟基苯甲酸,这些酚酸可能与铁皮石斛的抗氧化、增强免疫力、降血糖等功效有关,这将为铁皮石斛活性物质研究与开发提供参考。     

蜂蜜黄酮类化合物检测方法建立及其在云南5种特色蜂蜜中的分布

建立蜂蜜中芦丁、杨梅酮、槲皮素、莰菲醇4种黄酮化合物含量的固相萃取-高效液相色谱检测方法。蜂蜜样品用pH2的盐酸溶液溶解、离心后,用Oasis HLB固相萃取柱吸附与净化,4种黄酮经VP-ODS色谱柱(150mm×4.6mm,5μm)分离,紫外检测器检测,检测波长270nm。流动相为甲醇-水(pH3.0)(60:40,V/V),流速0.7mL/min。检出限：芦丁、杨梅酮均为0.05mg/kg,槲皮素、莰菲醇均为0.04mg/kg;回收率：芦丁91%～92%、杨梅酮82%～85%、槲皮素84%～86%、莰菲醇86%～89%。分析云南省的5种特色蜂蜜样品,结果表明不同品种蜂蜜中4种黄酮类化合物含量差异显著,显示蜂蜜黄酮类化合物含量可作为鉴别蜂蜜品种的一个指标。     

酶联免疫吸附法检测动物源性食品中氨苯砜残留

应用间接竞争酶联免疫吸附技术,建立了一种快速检测动物源性食品中氨苯砜残留的方法,并对其各项技术参数进行了评价。结果显示,该方法的半数抑制浓度IC50为0.369μg/L,对鸡肉、猪肉样本的检测限为0.2μg/kg,对鸡蛋、蜂蜜样本的检测限为2μg/kg,对牛奶样本的检测限为0.6μg/L;样本添加回收率为78.2%~104.0%,变异系数为5.2%~13.5%;对实际样本的检测结果与液相色谱-串联质谱法基本一致。该方法操灵敏度高、快速准确,适用于动物源性食品中氨苯砜残留的快速检测。     

TripleTOF^TM 5600液相色谱高分辨串联质谱仪

液相色谱高分辨串联质谱仪（TripleTOFTM 5600 LC/MS/MS）是AB Sciex公司新近推出的分析仪器,它是世界上首台集准确质量数、高分辨率、高速扫描速度和高定量灵敏度等优点于一体的质谱系统平台。     

三聚氰胺检测五LC/MS/MS法分析食品中的三聚氰胺

奶粉类食品前处理 1.所需试剂及耗材 1%三氯乙酸溶液,0.1mol/L盐酸溶液,5%氨水-甲醇溶液,以及Oasis MCX固相萃取柱(60mg/3mL,或相当者),使用前分别用3mL甲醇、3mL0.1mol/L盐酸溶液对固相萃取柱进行预处理,并保持柱体的湿润.     

Determination of aflatoxins in food using LC/MS/MS

 A liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometric method is described for the determination of aflatoxins B₁, B₂, G₁ and G₂ in food with the use of aflatoxin M₁ as an internal standard. The method works well with matrices such as those of figs and peanuts, but there are problems with spices, due to limitations of the clean-up method used. Received: 15 October 1997     

液相色谱-串联质谱术在生态纺织品检测中的应用

伴随人们环保和安全意识的提高,生态纺织品的安全检测越来越受到人们的关注.本文介绍液相色谱-串联质谱技术在生态纺织品有害物质,如禁用偶氮、致癌致敏染料、烷基酚聚氧乙烯醚、杀虫剂残留测定中的应用.     

Multiresidue method for pesticides and veterinary drugs in bovine milk using GC/MS and LC/MS/MS

A simple, sensitive and selective method with gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS) has been developed to detect 342 pesticides and veterinary drugs contaminating bovine milk at the maximum residue limits (MRLs) defined in the "positive list system". Sample preparation was performed by extracting the analytes with acetonitrile, followed by salting-out with sodium chloride. For some pesticides, the extract was further cleaned up by n-hexane partitioning and PSA cartridge column chromatography. GC/MS-EI or -NCI was used to determine pesticide residues, while LC/MS/MS-ESI was applicable to the determination of pesticide and veterinary drug residues. The variation of the recoveries of these drugs at MRL was relatively wide; however the relative standard deviations of the recovery of each drug were within 28%, suggesting that the present method is good enough for use as a screening test for contaminants at the MRLs. These results show that this method is useful for multiresidue analysis of numerous pesticides and veterinary drugs in bovine milk.     

Simultaneous determination of quinolones in foods by LC/MS/MS

A simple method was developed for the simultaneous determination of seven quinolones (enoxacin, ofloxacin, ciprofloxacin, danofloxacin, lomefloxacin, enrofloxacin and sarafloxacin) in foods using liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The seven quinolones were extracted with acetonitrile containing 0.2% formic acid, and the extracted solution was cleaned up on a C18 cartridge. The extract was diluted with 5 mmol/L IPCC-MS3 for injection into the LC-ESI-MS/MS. The LC separation was carried out on an ODS column with gradient elution of 5 mmol/L IPCC-MS3-acetonitrile as the mobile phase. Mass spectral acquisition was done in the positive ion mode by applying selected reaction monitoring (SRM). The recoveries of the seven quinolones were mostly greater than 60% from foods fortified at 10 ng/g. The detection limits in foods were 2 ng/g for enoxacin and ciprofloxacin, and 1 ng/g for the other drugs. Twenty cattle muscle, 7 swine muscle, 9 chicken muscle, 16 milk, 19 prawn and 20 broiled eel samples from retail markets were analyzed by this method. Enrofloxacin and its metabolite ciprofloxacin were detected in 9 broiled eel at the level of trace (tr)-34 ng/g and tr-10 ng/g, respectively.     

Direct nanoHPLC-ESI-QTOF MS/MS analysis of tryptic caseinophosphopeptides

Caseinophosphopeptides (CPPs) were generated following tryptic hydrolysis of sodium caseinate. Hydrolysate peptides were separated and identified using nano-HPLC ESI-QTOF MS/MS. Sequence coverage in the 3 h hydrolysate was 79.4%, 55.6%, 80.9% and 68.1% for α_s1-, α_s2-, β- and κ-casein (CN), respectively. Variable levels of serine phosphorylation in β-CN f1–25 were observed in the 3 h hydrolysate. Analysis of β-CN f1–25 4P demonstrated that this peptide was stable during the course of hydrolysis. The effect of heat treatment (75 °C, 45 min) at pH 6.0, 7.0 and 8.0 on the peptide profile of the 3 h hydrolysate was studied. Compared to pH 6.0 and 8.0, least modification in phosphopeptide profiles was observed for the hydrolysate sample heated at pH 7.0. Different dephosphorylation and oxidation patterns were also observed following heat treatment at the three pH values. These results demonstrate that heat treatment, in addition to pH, has a major effect on both the phosphorylated and non-phosphorylated peptide profiles of CN hydrolysates.     

基于UPLC/Q-TOF MS/MS的芝麻油成分分析

为发现芝麻油中新成分,通过UPLC/Q-TOF MS/MS对4种芝麻油甲醇提取液进行检测分析。结果表明：4种芝麻油中共发现143种共同物质,其中正离子模式71种,负离子模式72种。共同物质中鉴定出77种物质,其余66种为未鉴定成分;77种鉴定成分中包括脂肪酸及衍生物（8种）、芝麻素、芝麻林素、硬脂酰胺等12种已知成分,其余65种为新发现成分;新发现成分包括油酸酰胺、棕榈酰胺、亚油酰胺、芥酸酰胺、8-甲基-N-香草基壬酰胺、辣椒酰胺、N-硬脂酰丙氨酸等17种脂肪酸酰胺,十六碳烯酸、十八碳烯酸等22种脂肪酸及衍生物,5-脱氧基维醇、天孢菌素等5种类黄酮,马泰树脂醇、银杏酸等21种其他成分。芝麻油中含有大量新成分和未知成分,富含的脂肪酸、脂肪酸酰胺、类黄酮、木脂素等物质可解释其独特生理功能。     

液相色谱-电喷雾串联质谱法测定豇豆中的水胺硫磷

建立了豇豆中水胺硫磷的液相色谱-电喷雾串联质谱分析方法。样品经乙腈超声提取后进行液相色-电喷雾串联质谱分析。方法检出限为0.1μg/kg(S/N=3)。空白样本添加水平在0.1、1.0、5.0μg/kg时,平均回收率为80.1~87.9%,相对偏差(n=6)为6.7~8.1%。使用MRM-IDA-EPI的模式,一次进样可得到MRM色谱图及MS2质谱图。该方法具有前处理简单、回收率高、精密度好,选择性强,灵敏度高的优点,符合农药残留的分析要求。