同位素内标液相色谱-串联质谱法测定婴儿配方奶粉中雌二醇残留

建立了一种婴儿配方奶粉中雌二醇残留的高效液相色谱-电喷雾串联质谱测定方法。样品经乙腈提取、浓缩、正己烷净化,用高效液相色谱分离后,采用电喷雾串联质谱进行定性和定量检测。线性范围为5~100 ng/mL,线性相关系数r大于0.99,方法的定量检出限为1.0μg/kg(S/N=10),高、中、低3个水平的加标回收率为81.5%~112.4%。     

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。     

液相色谱-串联质谱测定乳制品中乳酸链球菌素

建立液相色谱-串联质谱法用于测定乳酸链球菌素的含量。PLRPS-S为色谱柱。样品经提取净化后,用超高效液相色谱分离后采用电喷雾串联质谱进行定性和定量检测。线性范围为0～1 000μg/L,线性相关系数r大于0.99,方法检出限为0.2 mg/kg,在加标浓度为0.2～5.0 mg/kg条件下的回收率为89.01%～104.52%,精密度为1.99%～8.77%。方法简单、灵敏、准确、精密,满足检测需求。     

超高效液相色谱-串联质谱法测定食用植物油中的游离棉酚

目的建立超高效液相色谱-电喷雾串联质谱测定食用植物油中游离棉酚的方法。方法样品采用无水乙醇溶液提取,C18色谱柱分离,电喷雾串联四极杆质谱仪进行检测。结果棉酚的质量浓度在0.001~1.0μg/mL范围内具有良好的线性关系。食用植物油中的棉酚在5、50、250μg/kg 3个添加水平下,平均回收率为70.6%~94.4%,相对标准偏差小于12.0%;方法检出限LOD(S/N≥3)为1μg/kg,定量限LOQ(S/N≥10)为5μg/kg。结论该方法快速简单,结果准确,重现性好,适用于食用植物油中的游离棉酚含量的测定。     

HPLC-ESI-MS/MS测定牛奶中四环素类抗生素残留

建立高效液相色谱-电喷雾串联质谱法检测牛奶中土霉素、四环素及金霉素残留的分析方法。采用酸化乙腈提取样品并沉淀蛋白,离心、浓缩、正己烷脱脂,经Agilent ZOBAX SB-C18柱分离,以0.1%甲酸-乙腈对待测成分进行梯度洗脱。采用高效液相色谱-串联质谱多反应监测正离子模式检测,外标法定量。结果表明,3种抗生素浓度在50~1 000μg/L范围内线性关系良好,方法定量限(LOQ,S/N=10)为15~25μg/kg,检出限(LOD,S/N=3)为8~15μg/kg,加标回收率为79.6%~88.7%,相对标准偏差为3.2%~6.0%。该方法前处理简单、可靠,灵敏度高,适用于牛奶中四环素类抗生素残留的快速测定。     

方便面中丙烯酰胺含量的检测

建立了方便面中丙烯酰胺的液相色谱-串联质谱分析方法.样品用水提取,酶解,净化.以水(0.1%甲酸):乙腈=90:10(V/V)为流动相经反相色谱柱分离后,采用液相色谱串联质谱多反应监测正离子模式检测,丙烯酰胺定性定量离子对为m/z72.10/55.00,同位素内标物定性定量离子对为75.00/58.00.空白样品及其添加实验结果表明,特征离子相对强度比值稳定,无基质干扰,结合保留时间可实现准确的定性定量,方法检出限为25μg/kg(S/N=3),样本添咖水平在5～200μg/kg时,平均回收率为68.1～90.1%,相对偏差(n=6)为4.3%～6.1%.该方法前处理简单、回收率高、精密度好,可满足方便面中丙烯酰胺的确证分析要求.     

超高压液相色谱-串联质谱法测定腐竹、米线、年糕中的乌洛托品

目的 建立腐竹、米线、年糕中乌洛托品的超高压液相色谱-串联质谱分析方法。方法 样品经粉碎后, 用乙腈提取, MCX小柱净化, Waters ACQUITYTM UPLC BEH HILIC色谱柱分离, 最后在电喷雾正离子多反应监测模式下, 用超高压液相色谱-串联质谱仪进行分析。结果 乌洛托品在1.00～100.00 μg/L的范围内呈现良好的线性关系良好, 线性方程为Y=2391.11X+253.197, R2大于0.99。该方法检出限(S/N=3)和定量限(S/N=10)分别为0.30 μg/kg 和1.00 μg/kg。在1.00、10.00、50.00 μg/kg三个添加水平下, 乌洛托品平均回收率为82.0%～107.0%, 相对标准偏差为6.3%～15.6%。结论 该方法操作简便、检出限低, 能够满足腐竹、米线、年糕中乌洛托品检测的要求。     

UPLC-MS/MS法分析茶叶中的灭多威农药残留

建立了检测茶叶中灭多威残留的超高效液相色谱-串联质谱(UPLC-MS-MS)分析方法。茶叶样品经乙腈提取,氨基固相萃取柱净化,反相液相色谱对样品进行分离,采用多反应监测模式(MRM)进行定性、定量分析。结果表明:方法检出限为0.5μg/kg,定量限为2.0μg/kg;当添加浓度水平为10、100μg/kg时,加标回收率为71.9%～113.5%,相对标准偏差为5.3%～12.5%。该法灵敏度高、干扰小、定性准确,适用于茶叶中灭多威残留检测,同时可作为液相色谱检测的验证方法。     

固相萃取-液相色谱-串联质谱法同时检测猪肉中18种苯二氮卓类药物残留量

建立了同时检测猪肉中18种苯二氮卓类药物残留的液相色谱-串联质谱(LC-MS/MS)分析方法。样品中的苯二氮卓类药物残留在pH 5.2的乙酸铵缓冲溶液中酶解后,用氨水调节pH值大于9.5,经乙酸乙酯-异丙醇(体积比5∶1)提取,正己烷去脂,MCX离子交换柱净化,采用电喷雾正电子模式电离,多反应监测模式检测,同位素内标法定量。结果表明:在0.5～50.0μg/L范围内18种苯二氮卓类药物的线性相关系数均大于0.999 0,检出限(S/N≥3)范围为0.01～0.13μg/kg,定量限(S/N≥10)范围为0.04～0.45μg/kg。添加浓度水平为1.0,2.0和5.0μg/kg时,平均回收率范围为76.0%～107.2%,相对标准偏差(RSD)范围为2.3%～9.1%。     

奶粉中VK1的超高效液相色谱定量和串联液质确证分析

建立婴幼儿奶粉中VK1的超高效液相色谱(UPLC)检测方法和液相色谱-串联质谱(LC-MS/MS)检测确证方法。经研究,对国标检测方法的前处理过程稍作改进,减少基质干扰,操作简便,提取率稳定。UPLC法检出限为40μg/kg(S/N=3),LC-MS/MS法检出限为3.5μg/kg(S/N=3);样本添加水平在500μg/kg～2 000μg/kg时,平均回收率为78.4%～88.1%,相对偏差(n=6)为3.7%～6.4%。该方法能够满足奶粉中VK1含量的准确测定。     

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.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.