固相萃取-高效液相色谱-串联质谱法测定酱油中4-甲基咪唑

建立固相萃取-高效液相色谱-串联质谱/质谱法(SPE-HPLC-MS/MS)测定酱油中4-甲基咪唑的分析方法。试样经水稀释提取,LC-SCX固相萃取柱净化后,以乙腈和5mmol/L乙酸铵溶液(含0.1%甲酸,V/V)作为流动相,C18色谱柱分离,采用电喷雾离子源,正离子扫描多反应监测(MRM)模式进行检测。4-甲基咪唑在5~500μg/L浓度范围内呈良好线性关系,相关系数(r2)大于0.99,加标回收率为83.6%~95.1%,相对标准偏差为7.3%~8.2%,方法检出限为5μg/kg,定量限为10μg/kg。方法简单快速、准确灵敏,适用于酱油中4-甲基咪唑的测定。     

离子交换固相萃取-超高效液相色谱-串联质谱法快速测定腐竹中的乌洛托品

目的建立腐竹中乌洛托品的超高效液相色谱-串联质谱(UPLC-MS/MS)测定方法。方法样品经乙腈/水(1:1,v:v)溶液超声提取,阳离子交换柱净化后,经Waters Acquity UPLC BEH HILIC(2.1 mm×100 mm,1.7μm)色谱柱分离,在电喷雾正离子多反应监测模式下进行测定。结果乌洛托品在0.5~100.0μg/L范围内线性关系良好,相关系数(r)大于0.999。方法检出限和定量限分别为6μg/kg和20μg/kg。在20、40、100μg/kg 3个空白加标水平下,乌洛托品的加标回收率为100.1%~103.9%,相对标准偏差为4.7%~8.9%。结论该方法快速、简便、准确可靠,适用于腐竹中非法添加的乌洛托品的含量测定。     

超高效液相色谱-串联质谱法同时测定配方奶粉中泛酸、生物素和氰钴胺素

建立了超高效液相色谱-串联质谱联用技术同时测定配方奶粉中泛酸、生物素和氰钴胺素的方法。样品经水溶超声提取、三氯甲烷除蛋白后,进行超高效液相色谱-串联质谱分析,采用HSS T3液相色谱柱分离,以10mmol/L乙酸铵溶液(含0.1%甲酸)和乙腈作为流动相进行梯度洗脱,采用电喷雾-正离子电离源多反应监测模式进行定性和定量分析。结果表明:泛酸(VB5)的方法定量限为5μg/100g,生物素(VB7)为2μg/100g,氰钴胺素(VB12)为0.2μg/100g;回收率为79.4%~87.8%,相对标准偏差为3.3%~5.3%。泛酸的线性范围0.5~1000ng/m L,生物素为0.2~10ng/m L,氰钴胺素为0.02~10ng/m L。该方法分析操作简单、速度快、灵敏度高、重复性好,适用于配方奶粉中泛酸、生物素和氰钴胺素的同时测定。     

丝织物中酸性金黄G的液相色谱-质谱法测定

建立了固相萃取-超快速液相色谱-电喷雾串联三重四级质谱(SPE-UFLC-ESI-MS/MS)联用技术测定丝织物中的酸性金黄G。样品经SPE提取和净化后,采用ACQUITY UPLC BEH C18柱(100 mm×2.1 mm,1.7μm)色谱柱,乙腈(含0.1%甲酸)和水(含0.1%甲酸)为流动相进行梯度洗脱,电喷雾离子源电离,负离子多反应监测模式进行定性定量分析。酸性金黄G染料在0.5~100.0μg/L范围内线性良好,相关系数0.999 5,方法检出限为0.17μg/kg,回收率为97.2%~102.3%。     

高效液相色谱-串联质谱法测定白酒中的阿魏酸

建立了一种快速准确测定白酒中阿魏酸的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。样品经简单前处理后,以乙腈和含0.1%甲酸的水溶液为流动相,在电喷雾多反应监测模式下进行质谱分析。实验结果显示,该方法线性相关系数R~2大于0.9999,检出限为1.41μg/L,定量限为4.70μg/L,样品的回收率为101.1%～101.3%,相对标准偏差为0.10%～2.00%。方法简单、快速、准确、灵敏,为白酒中阿魏酸的研究提供了可靠的检测方法。     

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。     

超高效液相色谱-串联质谱法测定畜禽肉中17种磺胺类药物残留

目的建立超高效液相色谱-串联质谱(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)测定畜禽肉组织中17种磺胺类药物残留的方法。方法样品经乙腈提取、浓缩,正己烷脱脂后在正离子模式下以电喷雾电离串联质谱进行测定,外标法定量。结果 17种磺胺类药物在5μg/L~100μg/L范围内线性良好,相关系数0.99,方法检出限为2μg/kg,定量限为5μg/kg。在10、20、100μg/kg的添加水平下,17种磺胺类药物的平均回收率在84.0%~114.2%之间,相对标准偏差(relative standard deviation,RSD,n=6)在0.59%~7.96%之间。结论本方法快速、准确、灵敏,可应用于畜禽肉中17种磺胺类药物残留的同时检测。     

超高压液相色谱-串联质谱法快速测定酒类中的4种甜味剂

目的建立酒类中安赛蜜、糖精钠、甜蜜素和三氯蔗糖4种甜味剂的超高压液相色谱-串联质谱联用(UPLC-MS/MS)快速测定方法。方法采用AgilentZORBAXSB-C18色谱柱(50mm×2.1mm,1.8μm)分离,以0.1%甲酸水溶液-甲醇作为流动相梯度洗脱,在电喷雾离子源ESI负离子模式下多重反应监测(MRM)定性、定量测定甜味剂。结果 4种甜味剂在10～500μg/L的范围内与峰面积有良好的线性关系,相关系数大于0.99,检出限为0.5～2.4μg/L,加标回收率在89.4%～104.6%之间,RSD小于4%。结论该方法简便灵敏,准确快速,可用于酒类食品中低剂量、复合甜味剂的测定。     

离子交换固相萃取-超高效液相色谱-串联质谱法 快速测定腐竹中的乌洛托品

目的 建立腐竹中乌洛托品的超高效液相色谱-串联质谱(UPLC-MS/MS)测定方法。方法 样品经乙腈/水(1：1, v/v)溶液超声提取,阳离子交换柱净化后,经Waters Acquity UPLC BEH HILIC(2.1 mm × 100 mm,1.7 μm)色谱柱分离,在电喷雾正离子多反应监测模式下进行测定。结果 乌洛托品在0. 5 ~ 100 μg/L范围内线性关系良好,相关系数(r)大于0. 999。方法检出限和定量限分别为6 μg/kg和20 μg/kg。在20、40、100μg/kg 三个空白加标水平下,乌洛托品的加标回收率为100.1% ~ 103.9%,相对标准偏差为4.7% ~ 8.9%。结论 该方法快速、简便、准确可靠,适用于腐竹中非法添加的乌洛托品的含量测定。     

超高效液相色谱-电喷雾串联质谱测定食品中对位红的检测方法研究

建立了超高效液相色谱-电喷雾串联质谱法测定食品中对位红的检测方法。样品经提取后,采用了Waters Oasis HLB作为固相萃取小柱,进行样品净化,经超高效液相色谱分离后采用电喷雾串联质谱进行定性及定量检测。线性范围为0.1～1.0mg/L,线性相关系数为0.999。方法的定性检出限(S/N=3)为0.26μg/kg,定量检出限(S/N=10)为0.85μg/kg。高、中、低3个浓度水平的加标回收率范围为80.5%～109.5%,相对标准偏差小于10%。     

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.