为揭示各项理化特性对窖泥细菌群落结构的影响,分析不同年份窖泥的理化因子差异及与其原核微生物群落的相关性.结果表明:20?a窖池池壁和池底窖泥中的水分、pH值、铵态氮及有效磷和速效钾的含量均显著高于2?a窖泥,但其钙含量却显著低于2?a窖泥.30?a池壁和池底窖泥与2?a相比,除水分含量和腐殖质外,其他指标均存在显著差异.理化因子与菌群的相关性分析发现,水分含量、pH值和铵态氮对菌群的影响最为显著,与Lactobacillus呈极显著负相关(P<0.01),与Aminobacterium、Syntrophomonas和Sedimentibacter等6个菌属呈显著正相关(P<0.05).新窖泥中不同的微生物菌群在长期往复的发酵过程中相互作用,优势菌属逐步占据主导低位并达到动态平衡,形成优质窖泥.本实验系统研究窖泥原核微生物群落多样性在窖泥老熟及退化过程中的变化趋势,借助微生物和理化因子之间的相关性分析,为窖池的养护机制及优质窖泥的制作提供一定理论依据.

为提高农产品废渣利用价值,通过安卡红曲霉(Monascus anka)As 3.4811液态发酵豆渣、麦麸和梨渣制备膳食纤维.采用扫描电镜、X-衍射光谱、红外光谱、紫外-可见光谱及高效液相色谱(HPLC)等,对安卡红曲霉As 3.4811发酵豆渣、麦麸和梨渣膳食纤维进行结构表征、特性分析及橘霉素含量检测.结果表明,安卡红曲霉As 3.4811发酵后,豆渣、麦麸和梨渣不溶性膳食纤维的基质被破坏,使其内部结构暴露出来,纤维结晶度降低;豆渣、麦麸和梨渣膳食纤维分子内氢键断裂,寡糖含量增加;豆渣和梨渣中的红曲色素主要有橙色素,而麦麸中的红曲色素主要含有黄色素;红曲霉种子液、豆渣、麦麸和梨渣发酵液中橘霉素含量分别为9.8μg/L、9.4μg/L、8.8μg/L和9.0μg/L.因此,安卡红曲霉As 3.4811液态发酵可以改善豆渣、麦麸和梨渣膳食纤维结构及其特性.

本实验建立了同时测定食品包装印刷油墨中二苯甲酮(BP)、4-甲基二苯甲酮(MBP)、2-苯甲酰苯甲酸甲酯(OMBB)、4-二甲氨基苯甲酸乙酯(EDAB)、2-异丙基硫杂蒽酮(ITX)、4-二甲氨基苯甲酸-2-乙基己酯(EHA)、2,4-二乙基硫杂蒽酮(DETX)和4-氯二苯甲酮(CBP)等8种光引发剂(PIs)含量的凝胶渗透色谱(GPC)-气相色谱串联质谱(GC-MS/MS)方法.样品用环己烷-乙酸乙酯混合溶剂超声提取,提取溶液经GPC净化分离和富集以后,以50％苯基-50％甲基聚硅氧烷为固定相(Rtx-17MS),采用多反应监测(SRM)方式对上述8种光引发剂进行了定性和定量分析.8种光引发剂在0.2～100.0 μg/L范围内的线性关系良好,线性相关系数大于0.9979;在3种浓度的添加水平下,回收率范围为80％～ 105％,相对标准偏差为2％～ 10％;方法的定量限为0.01 ～～0.05mg/Kg.实验结果表明,采用该方法,样品前处理过程较简单,灵敏度高,准确度和精密度好,适用于食品料包装印刷油墨中8种光引发剂的检测要求.

An effective high performance liquid chromatographic (HPLC) method has been developed for the simultaneous determination of 9 ultraviolet stabilizers in food plastic packaging materials. The food packaging samples were firstly extracted by methanol-ethyl acetate, and then purified by a C18 solid-phase extraction (SPE) column. The target compounds were separated on a ZORBAX SB-C18 column (250 mm x 4.6 mm, 5 microm) in gradient elution mode using methanol and water as mobile phases. The detection wavelength was at 310 nm. The linear plots of the nine ultraviolet stabilizers were obtained between 0.2 and 10 mg/L, with the correlation coefficients of above 0. 999 for the nine ultraviolet stabilizers. The limits of detection for this method were in the range from 0.05 to 0.1 mg/L. The recoveries spiked in commercial food plastic packaging materials were in the range of 70.2% - 89.0% with the relative standard deviations of 0.4% - 4.5%. The results indicated that the method is simple, accurate, and suitable for the simultaneous determination of the nine ultraviolet stabilizers in food plastic packaging materials.

A new method of ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry(LC-ESI-MS/MS) for the analysis of chlorothiazide in raw milk was developed.After degreasing purification,the sample was extracted by ethyl acetate,and then chlorothiazide in which was determined by LC-ESI-MS/MS.Separated analytes were determined using multiple reaction monitoring(MRM).The quantitative analysis of target compounds was performed by the external standard method.The result indicated that the calibration curves were linear in the range of 5-100 μg/L for chlorothiazide.The correlation coefficients was 0.999.The quantification limit was 5 μg/L(S/N=10).The recoveries of chlorothiazide at three spiked levels of 0.01,0.05,0.1 mg/kg were in the range of 86%-105% with RSDs(n=6) less than 8%.This method shortened the time of pre-treatment process,and the result was credible.It could satisfy the requirement of mass and fast analysis in the laboratory.

5-对羟基苯乙内酰脲是制备羟氨苄青霉素和头孢氨苄等β-内酰胺类新型抗生素的重要原料[1],国内外报道其制备方法较多,主要有:(1)对羟基苯甲醛与氰化钠经一系列反应生成目标化合物[2];(2)乙醛酸与尿素、苯酚等在酸性条件下反应生成目标物[3].近年来,随着生物工程技术的发展,经研究由5-对羟基苯乙内酰脲(简称5-对羟基苯海因)通过乙内酰脲酶水解直接获得D-对羟基苯甘氨酸(β-内酰胺类抗生素的侧链),因此,研究新的高收率合成5-对羟基苯基乙内酰脲方法,将越来越引起人们的关注.本文在参考有关文献[4-6]的基础上,采用乙醛酸、尿素、苯酚等为原料,低碳醇(甲醇或乙醇)为催化剂,一步法合成5-对羟基苯乙内酰脲,对影响回收率的主要因素进行了详细的研究,并对其结构、纯度进行了分析测定.

A new method using of ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry(HPLC-ESI-MS/MS) for the analysis of 2-Dodecylcyclobutanone(2-DCB) in irradiated foods containing fat has been firstly developed.The samples were extracted by using ultrasound extraction technology.The extracts were dehydrated by anhydrous sodium sulfatecleaned and concentrated by rotary evaporation technology to get fat.The fat was cleaned up with neutral alumina column.And then determined by LC-ESI-MS/MS.Separated analytes were determined using multiple reaction monitoring(MRM).The result indicated that the calibration curves were linear in the range of 5～100 μg/L for 2-DCB.The quantitation limit was 0.08 mg/kg(fat).The recoveries of 2-Dodecylcyclobutanone were in the range of 75%～95%,with RSDs(n=6)10%.This method shortened the time of pre-treatment process,and the result was credible.It could satisfy the requirement of mass and fast analysis in the laboratory.

A new method for determination malachite green and its metabolites in aquatic water by ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry was developed.Sample preparation and HPLC-MS/MS analytical conditions were examined and optimized critically by a series of experiments.Samples were acidulated by acetic acid,then cleaned up,and ultimately LC-ESI-MS/MS method was adopted for qualitative and quantitative analysis.Limit of detections(LOD) was 0.5 μg/kg.The method showed good linearity(r>0.999) at the rang of 0.5-50 μg/L.The average recoveries ranged from 71.5% to 88.0%.The method is suitable for the trace analysis of MG in aquatic water owing to its high efficiency and convenience,and it can provide a basis for testing standard of malachite green in water.

A new method using of ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry for the analysis of Quizalofop-ethyl of phenoxy acid herbicide residues in the agricultural product has been developed.Sample preparation and HPLC-MS/MS analytical conditions are examined and optimized critically by use of a series of orthogonal experiments in this study.Samples are extracted by acetonitrile and acidulated by acetic acid,then cleaned up,and ultimately adopted LC-ESI-MS/MS method for qualitative and quantitative analysis.Limit of detections(LODs) of 0.01mg/kg or below were attained for Quizalofop-ethyl.The method showed good linearity(r20.999) for Quizalofop-ethyl.The average recoveries in the cereal ranged from 80% to 104%.The method is simple,efficient,sensitive,accurate.The technical indicators are detected pesticide residues at home and abroad to meet the requirements of the standard,which can apply for Quizalofop-ethyl of pesticide residues in the cereal trace analysis monitoring.

A new method for determining nitrovin in animal products by liquid chromatography-electrospray ionization tandem mass spectrometry was developed.Sample preparation and HPLC-MS/MS analytical conditions were examined and optimized.Samples were extracted,cleaned up and then detected by LC-ESI-MS/MS method.External standard method was used for quantification in the multiple-reaction monitoring mode.Limit of detection(LOD) was 2.0 μg/kg.The method showed good linearity in the range of 1.0-100.0 μg/L for nitrovin(r>0.99).The average recoveries of nitrovin in animal products ranged from 66% to 82%.

A new high performance liquid chromatographic(HPLC) method with ultraviolet detection was firstly developed for the determination of 2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chloro-2h-benzotriazole(UV-326) and 2-(2-hydroxy-3,5-di-tert-butylphenyl)-5-chlorobenzotriazole(UV-327) in composite laminated food packaging bags.The samples were extracted by ultrasound assisted extraction method.Then,the extracts were further concentrated by rotary evaporation technology and cleaned up with solid phase extraction column.The eluent was evaporated to near dryness under a stream of nitrogen and redissolved with methanol.The separation of target compounds was performed with Agilent ZORBZX SB-C18 column(250 mm×4.6 mm,5 μm) using methanol as elution reagent at a flow rate of 1.0 mL/min at 30 ℃.The quantitative analysis of target compounds was performed by the external standard method at a detection wavelength of 310 nm.The result indicated that the calibration curves were linear in the range of 0.2-10 mg/kg for UV-326 and UV-327 with both limits of quantitation of 0.2 mg/kg.The average recoveries of UV-326 and UV-327 were in the range of 75%-90% and 80%-85%,respectively,with RSDs of 3.6%-6.7% and 3.4%-4.2%,respectively.The method could be applied in the determination of UV-326 and UV-327 in composite laminated food packaging bags.

A high performance liquid chromatography-tandem mass spectrometry method was established for determination of quinotone in animal feed.Animal feed samples were extracted by a homogenater and an ultrasonic cleaner,purified by a solid phase ex-traction(SPE) cartridges [Alumia N(1 g,3 mL) ],detected by the positive electrospray ionization(ESI +) method under multiple reaction monitoring(MRM) mode.The calibration curves were liner(r > 0.998) in the concentration range of 0.01-0.2 μg/g.The extraction recoveries range from 81.9% to 111.6% in different spiked concentrations samples.The LOD was 5 μg/kg.

一、项目概述 没有好的包装,就没有好的食品,没有放心的包装,就没有放心的食品,食品包装材料成为食品安全的最后一道关,所以,食品包装材料的不安全将直接导致食品的不安全.

一、标准研究背景 我国是一个拥有13亿人口的农业大国,大米、小麦、玉米、大豆等农产品是我国主要的粮食作物,消费数量巨大,同时也是我国主要出口农产品之一.

一、前言 食品接触材料、容器与食品安全密切相关,国家在食品安全市场准入制度中规定只有合格的原材料、食品添加剂、包装材料和容器才能生产出符合质量安全要求的食品,因此食品接触材料、容器的安全性是食品安全的重要组成部分.

The GC-MS method for detection diaminomethylbezen in complex for food packaging material was established.In the range of 0.002-0.05 mg/L,diaminomethylbezen concentration was linear with ion peak area with linear coefficient of 0.9998.The detection limit was less than 0.0004 mg/L.The relative standard deviation of detection results was 2.98%-5.50%(n=6).The recoveries were 82%-92%.The method is fast,high sensitive and accurate.

A gas chromatography-mass spectrometry (GC-MS) method was developed for the simultaneous detection of 36 pesticide (including 9 kinds of pyrethroid pesticides, 12 kinds of organochlorine pesticides and 15 kinds of organophosphorus pesticides) residues in tea. The method was based on accelerated solvent extraction (ASE) with a mixture of acetonitrile and dichloromethane (1:1, V/V) and gel permeation chromatography (GPC) cleanup followed by GC-MS analysis of the extracts in selected ion monitoring (SIM) mode. The external standard method was adopted for quantitative analyses. At the three spike levels of 0.05, 0.2 and 1.0 mg/kg, mean recoveries for the 36 pesticides were between 67.8% and 110.2% with a relative standard deviation (RSD) ranging from 1.72% to 8.89%. The limits of detection were between 5 μg/kg and 55 μg/kg. This method is rapid, sensitive and accurate and can meet the demands for determining pesticides in tea samples.

<正> 茶叶是我国主要的经济作物,同时也是我国主要出口农产品之一。由于我国茶叶分散种植的特殊性,致使生产中使用的农药品种和数量较多。近年来,国外政府制定了一系列茶叶中农药残留限量标准,其要求检测的农药数量逐年增多,各农药的检测限值也越

A reversed-phase high-performance liquid chromatography(HPLC) method was developed for determination of water-soluble vitamins(ascorbic acid,niacin,panthothenic acid(vitamin B5),pyridoxine(vitamin B6),thiamine(vitamin B1),folic acid,and riboflavin(vitamin B2) in an energy beverage. Analytes were separated after solid phase extraction(SPE) with Supelco C18(500 mg/6 ml) cartridges and analyzed with HPLC on a Phenomenex C18(250 mm × 4.6 mm,5 μm) column with 0.1 mol/L KH2PO4(pH 7.0)-methanol(90:10,V/V) as mobile phase(0.5 ml/min) in isocratic mode. The identification of compounds was achieved by comparing their UV spectra with those of standard spectra in database and according to their respective time. The detection limit ranges from 0.05 to 0.2 mg/L and the accuracy of the method is between 94.71% and 97.03%.

本文介绍了氧化锡气敏传感器参杂金属（Sb,Ca,Sr）的制备及检测农药残留检测装置的原理,通过对氧化锡气敏传感器,在动态与静态条件下,检测农药残留的响应特征及影响因素进行了研究,如采用电压、占空比、电压波形（矩形波、正弦波、锯齿波、脉冲波）的变化,比较研究了农药残留检测的动态与静态响应特征,结果表明动态的测量方法比静态方法可以得到更多的信息,用这种动态测量方法检测对硫磷等有机磷类农药残留具有良好效果。