茶叶中10种农药残留的液相色谱-串联质谱法和气相色谱-串联质谱法测定

建立了茶叶中啶虫脒、乐果、吡虫啉、灭多威、甲基嘧啶磷、腐霉利共6种农药残留的液相色谱-串联质谱(LC-MS/MS)测定方法和溴氰菊酯、乐果、高效氯氟氰菊酯、p,p'-滴滴伊、甲基嘧啶磷、腐霉利、哒螨灵共7种农药残留的气相色谱-串联质谱(GC-MS/MS)测定方法。其中,乐果、甲基嘧啶磷和腐霉利三种农药均能通过两种方法测定。LC-MS/MS法测定的6种农药,在5~200 μg/L范围内线性关系良好(R2>0.995),在10、50、100 μg/kg加标水平下的回收率为70.0%~105.0%,相对标准偏差为0.3%~18.7%。GC-MS/MS法测定的7种农药,在10~500 μg/L范围内线性关系良好(R2>0.996),在10、50、300 μg/kg加标水平下的回收率为82.0%~110.0%,相对标准偏差为1.8%~12.0%。该方法完善了茶叶中10种农药残留检测方法针对实际样品的检测,灵敏度满足国外限量标准要求,适合出口茶叶中农药残留的测定。     

气相色谱法测定人参提取物中3种农药残留

建立GC-ECD(气相色谱-电子捕获检测器,Gas chromatograph-electron capture detector)检测人参提取物中五氯苯胺、腐霉利、烯酰吗啉3种农残的方法。人参提取物样品用水溶解,环己烷萃取,通过毛细管气相色谱-电子捕获检测器检测。五氯苯胺和腐霉利在范围为0.01μg/m L~1.0μg/m L(n=5),烯酰吗啉在范围为0.1μg/m L~10.0μg/m L标准曲线范围内线性良好,加标回收率平均值为97.71%~107.45%,RSD为1.61%~5.09%(n=9),检测限为1μg/kg~20μg/kg。该法可用于准确检测人参提取物中五氯苯胺、腐霉利、烯酰吗啉3种农残含量。     

固相萃取-气相色谱-质谱法检测食品中 腐霉利的残留量

目的建立固相萃取-气相色谱-质谱法检测食品中腐霉利的残留量。方法样品提取采用浸渍-振荡法,采用石墨化碳黑固相萃取小柱和中性氧化铝固相萃取小柱对不同来源(植物源性和动物源性)的样品溶液进行净化和萃取,然后经气相色谱-质谱法分析腐霉利的残留量。结果在0.005~1.0?g/m L范围内,腐霉利呈现良好的线性关系(r=0.9998)。茶叶、葡萄酒、猪肝样品分别按0.01~0.10 mg/kg添加3个水平的标样,回收率在81.4%~103.6%之间,RSD为3.5%~8.2%,检出限分别为0.025、0.01、0.025 mg/kg。结论该方法可适用于食品中腐霉利残留量的检测。     

气相色谱-串联质谱法测定三七中腐霉利残留量的不确定度评定

目的评定气相色谱串联质谱法测定三七中腐霉利残留量的不确定度评定。方法分析检测方法中不确定度的来源,并根据JJF1059.1-2012《测量不确定度评定与表示》,计算各不确定度的分量,合成标准不确定度,得到扩展不确定度。结果三七样品中腐霉利残留量为0.103mg/kg时,扩展不确定度为0.005mg/kg(k=2)。结论测定三七样品中腐霉利的不确定度主要来源于标准溶液的配制过程和标准曲线的拟合。     

气相色谱-质谱法同时测定三七须根中的5种杀菌剂残留

目的 建立一种气相色谱串联质谱法同时检测三七须根中5种杀菌剂残留量的方法。方法 用乙腈提取三七须根样品中的5种杀菌剂, 经氯化钠盐析, QuEChERS净化后, 利用气相色谱-质谱联法进行定性, 定量检测。结果 5种杀菌剂在0.05~5.00 μg/mL的浓度范围线性关系良好, 相关系数为0.9993~0.9998, 检出限为0.0001~0.0011 mg/kg, 高中低3种加标浓度的平均回收率为84.0%~102.5%, 相对标准偏差在2.52%~5.22% (n=5)。结论 该方法简单灵敏、高效可靠, 适用于三七根须中5种杀菌剂的快速检测。     

气相色谱-质谱法测定东北人参中9种农药残留

采用气相色谱-质谱法建立对东北人参中9种农药残留的测定方法。采用70%乙醇溶液提取人参中的五氯硝基苯、腐霉利、毒死蜱、甲基毒死蜱、噁霜灵、三唑醇、乙草胺、丙环唑、甲基立枯磷9种农药残留,通过环己烷萃取进行精制,利用气相色谱进行分离,质谱进行定量测定。研究结果显示农药组分的回收率在78.2%~122.4%,相对标准偏差均不大于5%,定量限为0.007 mg/kg~0.082 mg/kg。回收率情况表明,该方法用于人参样品的农药残留检测效果良好。采用本方法对中国东北地区收集的10批人参样品的农药残留进行了检测,样品农残检出率从高到低的顺序为五氯硝基苯腐霉利丙环唑乙草胺毒死蜱甲基立枯磷甲基毒死蜱噁霜灵三唑醇。该方法快速简便,经济且具有较高的灵敏度,可以应用于人参药材及其提取物的农药残留检测之中。     

QuEChERS结合气相色谱-三重四级杆串联质谱法测定动植物混合型食品中多种农药残留

建立了气相色谱串联质谱(GC-MS/MS)定量和定性检测动植物混合型食品中7种农药残留量的方法。样品中的待测农药组分经乙腈-乙酸乙酯混合溶剂(85∶15,v/v)提取,采用改进的Qu ECh ERS法为净化方法,以外标法进行定量,以气相色谱-三重四级杆串联质谱(GC-MS/MS)多反应监测模式(MRM)检测。在动植物混合性食品基质中,以该方法检测的大部分农药的线性范围为0.01μg/L~0.50μg/L,检测低限最低可以达到1.0μg/kg,添加回收率为67.2%~118.6%,相对标准偏差(RSD)为5.2%~16.3%(n=6)。该方法的准确性高、重复性好、操作简便,适用于动植物混合型食品中多种农药残留同时测定。     

气相色谱-质谱法检测植物油中腐霉利和氟硅唑含量

采用QuEChERS快速净化小柱进行快速样品前处理,利用气相色谱-质谱法检测植物油中腐霉利和氟硅唑农残含量。结果显示:腐霉利和氟硅唑加标回收率分别为85. 0%～96. 0%和88. 3%～94. 1%;精密度实验腐霉利和氟硅唑实验室内变异系数分别为1. 5%～8. 9%和2. 1%～6. 8%;腐霉利和氟硅唑的检出限分别为0. 007 5 mg/kg和0. 022 5 mg/kg。该方法前处理简便,灵敏度高,重现性好。     

微波萃取-GC/MS-MS测定乙二醇醚类有机溶剂

建立了气相色谱/串联质谱方法,测定纺织品中残留的15种乙二醇醚类有机溶剂。该方法以乙醇为萃取溶剂,100℃下微波萃取纺织品中残留的乙二醇醚类有机溶剂,萃取液直接进行气相色谱/串联质谱分析,外标法定量。在信噪比(S/N)为10的条件下,各组分的定量下限为5~20 mg/kg。在三个加标水平下,平均回收率为81.7%~94.5%,相对标准偏差为2.1%~6.8%。该方法简单快速,可满足纺织品中乙二醇醚类有机溶剂残留量检测的技术要求。     

高效液相色谱法测定番茄中腐霉利和异菌脲的 残留量

目的建立固相萃取-高效液相色谱法测定番茄中腐霉利和异菌脲的残留量。方法番茄样品用乙腈超声提取,加入氯化钠进行盐析脱水,提取液过Florisil柱净化,用正己烷/丙酮(90:10,V:V)淋洗液洗脱,洗脱液氮吹近干,甲醇定容后经ZORBAX Eclipse XDB-C_(18)(250 mm×4.6 mm,5μm)色谱柱进行分离,以乙腈/水(60:40,V:V)为流动相,流速为1.0 m L/min,采用二极管阵列检测器检测,检测波长为208 nm。结果在0.05~5.0 mg/L浓度范围内,腐霉利和异菌脲的质量浓度与其峰面积呈良好的线性关系(r~20.999),方法检出限均为0.025 mg/kg,在0.05、0.5和1.0 mg/kg 3个不同加标水平上,腐霉利和异菌脲的加标回收率为90.6%~102.4%,精密度为3.72%~6.55%。结论该方法操作简单、准确,可应用于番茄中腐霉利和异菌脲的检测。     

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.     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

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.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

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.     

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 Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.