液相色谱-串联质谱法检测鸡蛋中金刚烷胺残留

采用液相色谱-串联质谱(LC-MS/MS)法检测鸡蛋中金刚烷胺,比较不同类型色谱柱、提取溶液(甲醇-1%三氯乙酸水溶液与甲醇/氨-氯化铵缓冲液)和净化方式(正己烷分配去脂、正己烷/二氯甲烷反萃取及Oasis MCX固相萃取柱净化)。结果显示,用甲醇-1%三氯乙酸水溶液提取,正己烷分配去脂,经Agilent XDB-C18(150 mm×2.1 mm,3.5 m)色谱柱分离,LC-MS/MS检测效果最好。本方法检出限(LOD)为2μg/kg,线性范围在1~1 000μg/L之间,回收率88.0%~99.6%。方法操作简便,实用性强,精密度好,为禽产品的质量安全检测与监管提供方法依据。     

固相萃取-气相色谱-质谱法测定植物饮料中的9种植物毒素

建立了固相萃取(SPE)净化结合气相色谱-质谱联用(GC-MS)同时检测植物饮料中9种植物毒素(侧柏酮、龙蒿脑、长叶薄荷酮、黄樟素、甲基丁香酚、香豆素、α-细辛脑、β-细辛脑和山道年)的分析方法。样品高速离心后,采用HLB固相萃取小柱富集净化,洗脱液经氮吹浓缩,以DB-5MS色谱柱分离,GC-MS选择离子监测模式测定。实验表明,9种植物毒素在5~1000μg/L浓度范围内线性关系良好,相关系数均大于0.999;方法检出限(S/N=3)为0.3~1.4μg/kg,定量限(S/N=10)为1.0~4.7μg/kg;阴性样品的3个添加水平的平均回收率在76.3%~99.7%之间,相对标准偏差(RSD,n=6)小于8.7%。该方法处理简单,准确高效,适用于植物饮料中9种植物毒素的检测。8个实际样品的检测结果显示,有1个草本饮料样品检出0.7 mg/kg甲基丁香酚。     

固相萃取-超高效液相色谱-电喷雾串联质谱法测定食用油脂中3-氯丙醇酯

目的建立固相萃取-超高效液相色谱-串联质谱联用法(SPE-UPLC-MS/MS)同时测定食品中18种3-氯丙醇酯的方法,并对部分市售含油脂食品中氯丙醇酯的含量进行调查。方法样品用叔丁基甲醚-乙酸乙酯(8∶2,V/V)超声提取;经Sep-Pak Silica硅胶萃取小柱、OASIS HLB固相萃取小柱(预先用甲醇活化)二次净化,以Acquity UPLC BEH C_(18)色谱柱(2.1 mm×150 mm,1.7μm)分离,以多反应监测模式(MRM)进行监测,内标法定量。结果18种氯丙醇酯在1.0~200.0μg/L范围内线性关系良好(r为0.999 1~0.999 8)。食用油在0.10、1.0和10.0 mg/kg3个添加水平范围内的平均回收率为80.2%~98.5%,RSD8.1%。食用油中18种氯丙醇酯的检出限在1.17~30.1μg/kg之间,92.0%(46/50)的食用油中检出多种3-氯丙醇酯,含量分别在7.55~5 360μg/kg之间;75.0%(9/12)的含油脂食品中检出多种3-氯丙醇酯,含量在6.62~1 569.8μg/kg之间。结论建立的固相萃取-超高效液相色谱-电喷雾串联质谱联用法同时测定食品中18种3-氯丙醇酯的方法快速简单、准确有效,可以满足各种食用油和含油脂食品中3-氯丙醇酯的检测要求。     

高效液相色谱法检测乳品饮料中四环素类抗生素

建立一种用固相萃取-高效液相色谱法测定乳品饮料中土霉素、四环素、金霉素、强力霉素的检测方法。样品前处理用乙腈沉淀蛋白后,采用HLB固相萃取小柱进行净化和富集,氮气吹干后用流动相复溶上机检测。采用Waters RP C18色谱柱(4.6 mm×250 mm,5μm)分离,以乙腈∶甲醇∶0.01mol/L草酸溶液(18∶5∶77)作为流动相,用PDA检测器检测,外标法峰面积定量。结果表明,4种四环素类抗生素在0.10μg/m L~1.00μg/m L浓度范围内线性良好,相关系数r2为0.994~0.999,检出限均为2.0μg/kg~5.0μg/kg,定量限均为6.0μg/kg~15.0μg/kg,加标回收率达到77.6%~90.6%。     

毛细管SPE-GC法测定纺织品中邻苯二甲酸酯

建立了新型毛细管固相萃取-气相色谱法检测纺织品中邻苯二甲酸酯(PAEs)的方法。通过比较筛选出毛细管固相萃取柱的最佳萃取剂,并优化萃取条件,净化富集待测物质后与气相色谱联用进行定性定量检测。采用的毛细管内固相萃取条件为:选取C18中的萃取剂为毛细管固相萃取剂,1.2μL甲醇和1.2μL超纯水依次活化,上样速率0.5μL/min,热脱附。该方法在1~1 000μg/L质量浓度范围内线性关系良好;DMP、DEP和DBP的最低检出限分别是4.1μg/L、4.8μg/L和5.4μg/L;加标回收率分别是84%~99%、88%~97%和84%~98%;相对标准偏差(RSD)分别为5.34%、4.23%和6.02%。     

QuEChERS-超高效液相色谱-串联质谱法同时快速测定肉类食品中多种抗生素残留

目的建立能同时检测肉类食品中20种磺胺和8种喹诺酮类抗生素残留的Qu ECh ERS-超高效液相色谱-串联质谱法(UPLC-MS/MS)。方法样品加1%甲酸乙腈提取,经分散固相萃取净化后,采用Waters C18(2.1 mm×100 mm,1.7μm)色谱柱分离,梯度洗脱,采用电喷雾-正离子多反应监测模式,外标法定量。结果 28种抗生素在各自浓度范围内线性关系良好,相关系数(r)为0.997 5~0.999 6,检出限(LOD)为0.17~0.91μg/kg(S/N=3),磺胺类抗生素回收率在70.9%~115.2%之间,RSD在2.8%~15.9%(n=6)之间;喹诺酮类抗生素回收率在71.3%~112.3%之间,RSD在2.5%~14.6%(n=6)之间。结论建立的方法准确、快速、灵敏度高,可对动物源性食品中多种抗生素残留进行快速分析。     

固相萃取-超高效液相色谱串联质谱法测定牛奶中6种头孢菌素类抗生素

目的建立固相萃取超高效液相色谱串联质谱(SPE-UPLC-MS/MS)同时检测牛奶中6种头孢菌素类抗生素含量的方法。方法样品经0.05 mol/L的磷酸氢二钾缓冲溶液提取,HLB固相萃取柱净化,液相色谱串联质谱法测定,采用多反应监测模式进行定性和定量分析。结果 6种头孢菌素类抗生素的检出限(S/N=3)和定量限(S/N=10)范围分别为0.05~0.4μg/kg和0.1~1.6μg/kg。样品加标回收率范围为66.3%~110.0%。结论该方法便捷、快速、高效,能够满足牛奶中头孢菌素类抗生素的检测。     

DSPE-UPLC-MS/MS测定畜禽产品中壬基酚和双酚A

建立了分散固相萃取-超高效液相色谱-串联质谱法(DSPE-UPLC-MS/MS)测定畜禽产品中壬基酚和双酚A的分析方法。样品采用乙腈超声提取,无水Mg SO_4去除水分后,用N-丙基乙二胺(PSA)和十八烷基硅胶(C_(18))吸附剂分散固相萃取净化。采用Agilent Poroshell 120 EC-C_(18)柱(4.6 mm×50 mm,2.7μm)为分离柱,以甲醇和2 mmol/L氟化铵溶液为流动相,梯度洗脱。采用电喷雾离子源在负离子多反应监测扫描(MRM)模式下进行测定,内标法定量。在优化的试验条件下,壬基酚和双酚A的检出限为0.1μg/kg,定量限为0.3μg/kg;线性范围为1.0~50μg/kg,相关系数大于0.99。不同畜禽产品(猪肉、牛肉、鸡肉、猪肝和鸡蛋)在1.0,5.0和10μg/kg三个添加水平下的平均回收率为85.9%~110.7%,相对标准偏差(RSD)(n=6)为2.75%~10.65%。该方法准确灵敏、简便快速,适用于畜禽产品中壬基酚和双酚A的分析检测。     

GC-MS/MS法测定铁皮石斛中19种农药残留

建立固相萃取-气相色谱-三重四极杆串联质谱法测定铁皮石斛中19种农药残留的分析方法。石斛样品经乙腈提取,经ENVI-Carb/Florisil固相萃取小柱进行净化后,采用气相色谱-三重四极杆串联质谱法在多反应监测(MRM)模式下测定,外标法定量。19种农药成分在10μg/L~200μg/L范围内有良好的线性关系,相关系数在0.993 1~0.999 8范围内;19种农药成分在3个添加水平下(10、100、200μg/L),加标回收率范围为82.83%~109.29%,RSD%(n=5)为1.43%~5.74%;各农药成分的检出限均小于0.58μg/L。该方法可应用于石斛中多种农药残留的同时检测。     

固相萃取-高效液相色谱-串联质谱联用法检测辣椒及其制品和肉酱中的罗丹明B含量

建立了辣椒及其制品和肉酱中罗丹明B含量的固相萃取-高效液相色谱-串联质谱联用(SPELC-MS/MS)检测方法。样品经乙腈提取后,经中性氧化铝固相萃取柱净化,超高效液相色谱-串联质谱法检测。本方法定量限为0.1μg/kg,线性范围为0.2~50ng/mL;在罗丹明B添加水平为0.1~10μg/kg时,辣椒片样品中的回收率为76%~92%,辣椒制品中的回收率为74%~93%,肉酱样品中的回收率为70%~90%。     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status