燕窝中唾液酸的DAD/FLD串联HPLC测定方法研究

建立燕窝中唾液酸的柱前衍生二极管阵列/荧光检测器(DAD/FLD)串联的反相高效液相色谱检测方法。用硫酸氢钠溶液水解样品,以邻苯二氨盐酸盐为衍生化试剂,采用C18柱分离,四氢呋喃溶液(含体积分数0.5%磷酸和体积分数0.15%正丁胺)-乙腈为流动相等度洗脱,流速1.0mL/min,二极管阵列检测波长230nm,荧光激发波长(Ex)230nm,发射波长(Em)425nm。结果表明,唾液酸在0.1～750μg/mL范围内线性良好(r>0.9990),20min内完全分离,回收率在85.03%～97.14%之间。检出限0.2μg/mL(DAD),0.005μg/mL(FLD),FLD检出限比DAD低两个数量级且杂峰少,在DAD检出限以上的相同浓度下,DAD比FLD更灵敏。本方法具有灵敏度高,重复性好,分析速度快等特点,可准确测定燕窝等样品中唾液酸含量。     

超高效液相色谱-荧光检测法测定禽肉组织中乙氧酰胺苯甲酯残留量

建立超高效液相色谱-荧光检测法测定禽肉组织中乙氧酰胺苯甲酯（ethopabate，ETP）残留量的分析方法。样品用乙腈提取，采用C18色谱柱（2.1 mm×100 mm，1.8 μm），乙腈-水（30∶70，V/V）为流动相，流速0.3 mL/min，柱温30 ℃，进样量5.0 μL，采用荧光检测器，在激发波长272 nm、发射波长394 nm条件下测定。结果表明：ETP在5～500 ng/mL质量浓度范围内呈良好的线性关系（R2=0.999 7）；检出限为2 μg/kg，定量限为5 μg/kg；平均回收率为83.0%～91.5%，相对标准偏差为1.6%～2.9%。本方法适用于检测禽肉组织中ETP残留量。     

高效液相色谱-二极管阵列法测定高蛋白食品中的三聚氰胺

建立用高效液相色谱-二极管阵列法测定高蛋白食品中的三聚氰胺的检测方法.对不同样品采用不同的前处理方法,然后用Agilent TC-C18 4.6×250 mm色谱柱,柱温为40℃,流动相为0.02 mol/L硫酸铵∶甲醇=94∶6(V∶V),流速0.8 mL/min,二极管阵列检测器于235 nm波长下进行检测,并以保留时间和三维光谱图相似性系数进行定性,外标法定量.不同样品的加标回收率为98.8%～101.5%,RSD小于1.2%.方法线性范围为0.1～150μg/mL,检测限为0.01μg/mL,相关系数R=0.999 9.     

固相萃取-高效液相色谱-二极管阵列/荧光检测器串联法快速检测汁用甜橙中9种多甲氧基黄酮成分

建立固相萃取(solid phase extraction,SPE)前处理-高效液相色谱串联二极管阵列和荧光检测器(high performance liquid chromatography with diode array detector/fluorescence detector,HPLC-DAD/FLD)快速检测甜橙汁中9种多甲氧基黄酮(polymethoxyflavones,PMFs)的方法。橙汁经粗滤后过C18固相萃取柱,依次以超纯水、体积分数30%乙腈清洗除杂,乙酸乙酯洗脱,氮气吹干后用甲醇溶解,制得橙汁PMFs样品。以体积分数0.05%H3PO4、甲醇、体积分数50%四氢呋喃为HPLC流动相进行反相梯度洗脱,利用DAD、FLD同时获得各物质的紫外和荧光光谱及峰面积,从而对样品PMFs做定性和定量检测。该条件下,9种PMFs在10 min内实现快速分离。采用外标法定量,紫外检测波长330 nm,荧光激发和发射波长分别为340 nm和450/500 nm,各物质线性关系良好(R20.999),紫外和荧光定量限分别为4.00~61.2μg/L和0.024~0.61 mg/L(对原果汁),橙汁PMFs加标回收率为96.4%~104.2%(紫外)和94.2%~102.1%(荧光),2种检测器定量结果具有良好的一致性。该方法前处理简便、耗时短、成本低,适合橙汁中多甲氧基黄酮成分的快速检测。按本方法对11个汁用甜橙品系鲜榨汁进行了分析,结果显示"渝早橙"PMFs含量最高,具备进一步开发的优良潜力。     

高效液相色谱-二极管阵列检测器法测定洋葱中槲皮素的研究

文章建立了高效液相色谱-二极管阵列检测器法测定洋葱中的槲皮素方法，并对不同区域的洋葱中槲皮素进行了研究分析。样品经乙醇提取后，用无水乙酸镁吸收多余的水分后离心，用Agilent ZORBAX SB-C₁₈液相色谱柱(150 mm×4.6 mm,5 μm)，以甲醇和0.1%甲酸溶液为流动相，流速为1.0 mL/min，柱温为35℃，进样量为10μL，高效液相色谱-二极管阵列检测器检测范围190～400 nm，检测波长为254 nm。槲皮素在1～100μg/mL浓度范围内线性相关系数R为0.9998～0.9999，方法检出限为0.03 mg/kg，定量限为0.1 mg/kg,5、10、15μg/mL 3个浓度加标水平的回收率为96%～109%，相对标准偏差为0.06%～0.09%，提取和分析效果是报道文献方法的1.3～1.7倍。该方法前处理简单，科学性、准确性、重现性、精密性好，可用于洋葱中槲皮素分析检测，对全国8大主产区洋葱中槲皮素的分析研究发现甘肃酒泉产的含量最高。     

婴幼儿配方奶粉中维生素B2的快速测定

建立了婴幼儿配方奶粉中维生素B2的高效液相色谱快速测定方法.样品用质量分数为3％偏磷酸溶液提取,用高效液相色谱仪(C18柱)分析,流动相为甲醇-H2O (33∶67,体积比),流速1.0 mL/min,荧光检测器激发波长462 nm,发射波长522 nm,维生素B2以保留时间定性,外标法峰面积定量.结果表明,乳粉样品在5～50 mg/kg添加水平范围内,回收率在96.0％～101％之间,相对标准偏差1.14％～6.05％,方法的定量限为0.5 mg/kg.该法简便、准确,适用于乳粉中维生素B2检测.     

高效液相色谱-二极管阵列检测器法测定面粉及其制品中的硫脲

建立了高效液相色谱-二极管阵列检测器法测定面粉及其制品中硫脲的方法。样品经甲醇-乙腈水溶液提取后,在转速12000 r/min条件下离心5 min后,用C_(18)液相色谱柱(250 mm×4.6 mm,5 μm),以甲醇+乙腈+水(5+5+90)为流动相,流速为0.8 mL/min,柱温为40 ℃,进样量为10 μL,二级管阵列检测器检测范围190～810 nm,检测波长为200 nm。根据保留时间、二极管阵列检测器全扫描光谱和色谱峰纯度分析等进行定性分析。硫脲在0.0～30 μg/mL浓度范围内线性关系良好,线性相关系数R~2为0.99992,方法检出限分别均为0.5 mg/kg,定量限为2.0 mg/kg,5、10、20 mg/L 3个浓度加标水平的回收率为96.1%～98.0%,相对标准偏差为0.01%～0.03%。该方法前处理简便、灵敏度高、重现性和回收率好,具有良好的精密度、准确度,尤其是试剂使用量少,对环境友好,检测成本低,可用于面粉及其制品中的硫脲分析检测。     

HPLC-DAD-FLD同时测定柑橘果汁中12种多甲氧基黄酮和香豆素类物质

建立高效液相色谱-串联二极管阵列检测器和荧光检测器(high performance liquid chromatography-diode array detector-fluorescence detector,HPLC-DAD-FLD)同时检测柑橘果汁中12种多甲氧基黄酮、香豆素及呋喃香豆素类物质的方法。以0.01%磷酸、甲醇、乙腈组成三元流动相进行梯度洗脱,12种物质在30 min内实现基线分离。利用DAD和FLD获得各物质的紫外和荧光光谱信息,将柑橘果汁样品组分的光谱与之比对,并结合色谱保留时间,实现样品成分的定性分析。分别以320 nm和450 nm为紫外和荧光的检测波长,研究该方法的定量性能。结果显示:标准曲线线性关系良好;荧光定量限低至μg/L级,可作为紫外定量的重要补充手段;果汁回收率的紫外和荧光检测值分别为95.2%~104.8%和94.5%~103.5%。该方法对样品定性、定量分析准确,适合柑橘多甲氧基黄酮、香豆素等能发射荧光物质的检测。     

HPLC-DAD-MS法测定独活酊中的主要活性成分

为了控制独活酊剂质量,建立了高效液相色谱一二极管阵列检测器-质谱(HPLC-DAD-MS)联用检测独活酊中的4种主要活性成分——二氢欧山芹醇乙酸酯、蛇床予素、二氢欧山芹醇当归酸酯和二氢欧山芹醇的方法.结果表明:①MS和DAD结合适合主要活性成分定性,DAD适合定量;②4种主要活性成分的相对标准偏差均小于2%,蛇床子素的回收率为104.7%,检测限为1.093μg/mL.该方法适合独活酊中这4种主要活性成分含量的检测.     

高效液相色谱法快速测定植物油中苯并(a)芘含量

采用乙腈饱和正己烷除去植物油中大部分油脂,并用正己烷饱和乙腈数次提取苯并芘,采用HPLC系统在流动相为乙腈∶水(90∶10)、荧光检测器:激发波长384 nm,发射波长406 nm下检测,用外标法峰面积定量。结果显示:苯并芘在4.0~80.0 ng/mL浓度范围内峰面积与浓度线性关系良好,加标回收率为92.7%~98.2%,方法定量限为2μg/kg。该法简便易行、准确可靠。     

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.