高效液相色谱法测定葡萄酒中多菌灵的残留量

利用高效液相色谱法测定葡萄酒中多菌灵残留量,样品以乙酸乙酯提取,二氯甲烷萃取净化,以ODS-C18柱(4.6mm×250mm,5μm)进行分析,流动相(V乙酸乙酯∶V乙酸铵=55∶45)流速为1mL/min时,多菌灵保留时间为7.016min,回收率为87.8%～107.5%,最低检出限为2×10-5mg/kg。     

三重四级杆串联质谱法测定糯米(黄酒原料)中多菌灵残留量的不确定度分析

建立了评定GB/T 20770—2008《粮谷中486种农药及相关化学品残留量的测定——液相质谱联用法》中影响测量多菌灵不确定度多因素数学模型,考察了样品前处理及质谱测定的各个环节,根据建立的模型计算评定测量不确定度的各分量。采用该方法测得糯米中多菌灵的残留量为26.8×10-3±0.78×10-3mg/kg。分析表明,多菌灵残留量测定的不确定度主要来源于标准溶液的配制、样品前处理制备过程和样品溶液的平行测定差异。经计算,在置信概率P=95%时,运用该方法测定试样中多菌灵残留的相对标准合成不确定度为1.46%,标准不确定度为0.39×10-3mg/kg,扩展不确定度(K=2)为0.78×10-3mg/kg。     

烟草中"多菌灵"残留量的液相色谱-质谱测定

用甲醇-盐酸溶液提取,固相萃取净化,反相HPLC/MS法测定了35个烤烟烟叶样品中的"多菌灵"残留量.结果表明:①方法的检测限为1.0μg/kg,回收率90.8%~102.2%,相对标准偏差2.05%~4.21%;②烟叶样品中多菌灵的检出率约为1/4,检出量5.7~112μg/kg.     

加速溶剂萃取-固相萃取结合液相色谱分析茶叶中多菌灵残留量

建立了一种新型快速测定茶叶中多菌灵残留量的方法.采用加速溶剂萃取(ASE),Lc-SCX小柱净化,以甲醇-5mmol/L乙酸铵(两者体积比45:55)为流动相,配备Xterra-C18柱、紫外检测器(280 nm)的高效液相色谱仪.对待测组分进行了分离和测定.结果表明.空白茶叶样品中多菌灵添加回收率在75.0%～106.O%之间,相对标准偏差(RSD,n=6)小于10%;样品中多菌灵的最低检出限为O.01 mg/kg.本方法操作过程简单、快速,重复性好,能满足茶叶中多菌灵残留量的检测要求.     

QuEChERS-高效液相色谱法测定苹果中多菌灵和噻菌灵

目的以固相萃取(solid phase extraction, SPE)、QuEChERS作为前处理方法,采用高效液相色谱检测苹果中多菌灵和噻菌灵。方法样品加乙腈、MgSO4、无水NaCl、NaAc提取,离心,取上清液加PSA净化,离心,取2 mL上清液用氮气吹干,用1.0 mL流动相溶解后,经高效液相色谱测定,外标法定量。结果多菌灵和噻菌灵在0.5～10μg/mL范围内线性关系良好,线性相关系数(r2)均大于0.9999,在0.50、2.0和10μg/mL3个添加水平下,加标回收率为84.15%～99.28%,相对标准偏差(relativestandarddeviations,RSDs)为1.69%～3.40%(n=6),检出限小于0.1 mg/kg。结论与SPE法相比, QuEChERS法具有更低的检出限、操作简单快速,适用于苹果中多菌灵和噻菌灵的检测。     

超高效液相色谱-串联质谱法测定干香菇中的多菌灵和噻菌灵残留量

称取1.0g 干香菇样品,用0.02mol/L 盐酸- 甲醇(80:20,V/V)溶液浸泡提取,调节溶液pH 值至6～8,用二氯甲烷进行提取净化,旋转蒸发器减压蒸干后,用30% 甲醇水溶解,样液用超高效液相色谱分离,电喷雾串联四级杆质谱进行检测,外标法定量。本法研究的多菌灵和噻菌灵的线性范围为1.0～100.0μg/L,线性相关系数R2 ＞ 0.99,在1.0～10.0μg/kg 的3 个添加水平范围内的平均回收率为78%～106%,相对标准偏差为7.9%～9.8%,方法检测限可达1.0μg/kg,在3min 内快速完成分析测试,可应用于大通量的实际样品检测。     

PXC固相萃取-高效液相色谱法测定四川泡菜中的多菌灵、克百威

通过对四川泡菜进行固相萃取-高效液相色谱法测定多菌灵、克百威残留量.样品经乙酸乙酯提取后,PXC固相萃取柱提取净化,HPLC法测定.在添加水平为1,5,20μg/g时,多菌灵的回收率在86.3％～92.3％之间;RSD＜5％(n=6),检出限为0.03mg/kg,克百威的回收率在76.3％～89.4％之间;RSD＜5％(n=6),检出限为0.06 mg/kg,方法的测定结果满足农药残留量的检测要求.     

基于检测概率模型的表面增强拉曼光谱法快速筛查果蔬中多菌灵残留

目的 建立一种水果蔬菜中多菌灵残留的表面增强拉曼光谱(SERS)快速筛查方法。方法 样品经乙醇提取、二氯甲烷净化、氮吹浓缩和乙醇溶液复溶四步获取待测液,通过单因素实验,优化金纳米粒子、提取液、萃取试剂及促凝剂的加入量,确定拉曼光谱仪的仪器测试条件。结果 多菌灵的拉曼特征位移为 630±5 cm^-1、728±5 cm^-1、1 002±5 cm^-1、1 224±5 cm^-1、1 264±5 cm^-1、1 316±5 cm^-1,根据其拉曼光谱特征峰及其强度,对多菌灵进行定性快速测定。结合检出概率模型(POD),确定出多菌灵在苹果、柑橘等水果中的检出限为 0. 5 mg/kg,在辣椒等蔬菜中的检出限为 1. 0 mg/kg。结论 本方法操作简单、快速准确,从样品前处理到结果显示仅需 40 min,结合使用 POD 模型,验证了该方法的有效性,可应用于水果蔬菜中多菌灵的现场快速检测。     

高效液相色谱法同时测定烟草中吡虫啉、多菌灵、甲基硫菌灵的残留量

用固相萃取-高效液相色谱法对烟草中吡虫啉(imidacloprid)、多菌灵(carbendazim)、甲基硫菌灵(thiophanate-methyl)3种农药同时进行残留分析.用丙酮/水(1:1,V/V)提取,二氯甲烷萃取,紫外检测器分析,检测波长为270 nm,流动相为甲醇/水(60:40,V/V).试验结果表明,方法回收率吡虫啉为91.9%～97.1%,相对标准偏差为3.97%～10.01%;多菌灵为92.7%～99.9%,相对标准偏差为3.15%～5.37%;甲基硫菌灵为87.4%～95.3%,相对标准偏差为3.05%～4.61%.该方法操作简便,分离效果好,准确度和精密度均达到定量分析要求.     

液相色谱-串联质谱法检测蔬菜中氯吡脲残留量的前处理研究

目的利用正交实验构建一种液相色谱-串联质谱法检测蔬菜中氯吡脲残留量的前处理方法。方法通过加标回收率的比较,从二氯甲烷、乙酸乙酯、丙酮、乙腈中选择合适的提取溶剂和提取方式;选取氨基固相萃取柱为净化柱;从甲醇、二氯甲烷、甲醇-二氯甲烷等中选择适合的洗脱溶剂。使用20 m L乙腈体系对样品进行30 min提取,经氨基柱净化,二氯甲烷为淋洗液,甲醇为洗脱剂,45℃氮吹浓缩富集,甲醇溶液定容过滤后测定。结果通过加标回收率和精密度实验,结果表明平均加标回收率为91%~116%和相对标准偏差(RSD)为1.6%~5.6%。结论该方法简单、实用、快速,具有较高的准确度和重复性,可用于蔬菜中氯吡脲的残留量测定的前处理。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

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

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.