液相色谱-串联质谱法测定鸡蛋中氟虫腈及其代谢物的残留量

建立一种采用液相色谱-三重四级杆质谱测定鸡蛋中氟虫腈及其代谢物(氟甲腈、氟虫腈砜和氟虫腈硫醚)的快速筛查方法。鸡蛋样品经乙腈和正己烷提取,C18固相萃取柱净化,Shim-pack XR-ODSⅢ色谱柱(2.0 mm i.D×150 mm,2.1μm)分离,以乙腈-5 mmol/L乙酸铵(0.02%甲酸)水溶液为流动相,梯度洗脱,外标法定量。采用液相色谱-三重四级杆串联质谱动态多反应监测模式,以负离子采集进行定性筛查和定量分析。结果表明,氟虫腈及其代谢物在0～50μg/L质量浓度范围内线性关系良好,相关系数R2均大于0.999。以10倍信噪比确定各药物的定量限(LOQ),氟虫腈及其代谢物的定量限为0.3～0.6μg/kg。在0.5、5.0和10.0μg/kg添加水平下,氟虫腈及其代谢物的平均回收率为92.3%～105.1%,相对标准偏差(RSD)为1.2%～8.6%。该方法简便、快速、灵敏,适用于鸡蛋中氟虫腈及其代谢物的快速筛查和定量检测。     

QuEChERS-气相色谱-串联质谱-同位素内标法快速测定茶叶中氟虫腈及其代谢物残留量

采用QuEChERS前处理技术,建立气相色谱-三重四极杆串联质谱联用仪测定茶叶中氟虫腈及其代谢物残留量的分析方法。样品添加氟虫腈-~(13)C_2,~(15)N_2同位素内标后,用水浸润后乙腈提取,NaCl、无水MgSO_4盐析脱水,N-丙基乙二胺和石墨化碳黑净化,多反应离子监测模式测定,内标法定量。氟虫腈及其代谢物在0.4～100?μg/L范围内呈良好线性关系,相关系数(r2)均不小于0.995,定量限均为1?μg/kg,在4个添加水平(1、5、20、200?μg/kg)下的加标回收率为76.72%～96.53%,相对标准偏差(n=6)为4.76%～13.07%。该方法简单、灵敏、准确,适用于茶叶中氟虫腈及其代谢物的快速定量测定,方法的灵敏度满足日本、欧盟的残留限量要求。     

气相色谱-负化学源质谱法测定牛奶中氟虫腈及其代谢物残留

建立了气相色谱-负化学源质谱(GC-NCI-MS)测定牛奶中氟虫腈及其3种代谢物残留量的分析方法。牛奶经乙腈提取后,分散固相萃取技术QuEChERS(Quick,Easy,Cheap,Effective,Rugged,Safe)净化,HP-5MS分离,气相色谱-负化学源质谱进行测定,外标法定量。在质量浓度为2.5～100μg/L范围内,氟虫腈及其3种代谢物均有良好的线性关系,所有目标物的定量限(LQD)(S/N=10)均在0.03～0.15μg/kg范围内。样品加标质量分数为0.01,0.02 mg/kg和0.05 mg/kg时,氟虫腈及其3种代谢物的平均回收率为85.6%～102.4%,相对标准偏差(RSD)为3.6%～6.1%。该方法样品前处理简单,分析时间短,回收率和精密度等均符合氟虫腈及其3种代谢物检测技术的要求,适用于牛奶中氟虫腈及其3种代谢物残留的检测。     

气相色谱三重四极杆串联质谱法测定鸡蛋和鸡肉中氟虫腈及其代谢物残留量的研究

目的建立一种鸡蛋和鸡肉组织中氟虫腈及其代谢物残留的气相色谱三重四极杆串联质谱法(GC-MS/MS)检测方法。方法样品经乙腈提取液,Bond Elut EMR-Lipids法净化,去除鸡肉和鸡蛋组织中的脂类和蛋白质。质谱采用多反应监测模式(multiple reaction monitoring,MRM)对氟虫腈及其代谢物的定量离子和定性离子进行监测。结果本方法中氟虫腈及其代谢物在20.0~1000μg/L的浓度范围内,线性良好,相关系数r~2大于0.994,在10、20、50μg/L水平上的平均回收率在91%~114.32%之间,相对标准偏差(relative standard deviation,RSD)为0.4%~7.8%(n=6),氟虫腈及其代谢物的检出限(S/N=3)为2.0~3.5μg/kg,定量限(S/N=10)为6.0~10.5μg/kg。结论该方法具有前处理简便快捷、净化效果佳、灵敏度高、成本低等特点,适用于鸡蛋和鸡肉中氟虫腈的快速确认及定量检测。     

气相色谱-串联质谱正离子模式测定食品中氟虫腈和溴虫腈残留

建立食品中氟虫腈和溴虫腈残留的气相色谱-串联质谱(GC-MS/MS)分析方法。方法 试样经乙腈提取, N-丙基乙二胺(PSA)固相萃取柱(SPE)净化,采用GC-MS/MS以正离子模式多反应监测(MRM)定性、定量测定氟虫腈和溴虫腈。结果 该方法在5～50μg/L浓度范围内呈线性,相关系数r均大于0.998。氟虫腈和溴虫腈的添加回收率分别为78.2%～102.5%和77.0%～104.1%,RSD分别为6.8%～15.2%和6.9%～17.1%,二者的检出限(LOD)均为5μg/kg,定量限(LOQ)均为10μg/kg。结论 气相色谱-串联质谱法正离子模式是简便、快速、准确测定食品中氟虫腈和溴虫腈残留分析方法。     

气相色谱法和高效液相色谱-串联质谱法测定 鸡蛋中氟虫腈及代谢物残留

目的建立适用于鸡蛋中氟虫腈及其代谢物(氟虫腈砜、氟虫腈硫醚和氟甲腈)残留的电子捕获检测器-气相色谱法和高效液相色谱-串联质谱检测方法。方法通过Qu ECh ERS提取盐包(CEN EN-15662)用乙腈提取目标化合物,借助固相萃取(PRiMEHLB)作为净化手段,采用气相和液相质谱进行监测。结果气相色谱法和高效液相色谱-串联质谱法中4种分析物的定性限(limit of detection,LOD)分别为0.1μg/kg和0.02μg/kg;定量限(limit of quantification,LOQ)分别为0.5μg/kg和0.1μg/kg,在0.1~10.0μg/L和0.1~5.0μg/L范围内线性关系良好,相关系数r~2均大于0.999。在2.5,5和10μg/kg 3种加标浓度下,平均回收率分别为80.8%~103%和87.4%~101%,相对标准偏差(relative standard deviation,RSD,n=6)分别为0.84%~5.62%和0.87%~4.40%。结论该方法步骤简便、可靠、稳定,适合于蛋类中氟虫腈及其代谢物残留的痕量分析。     

QuEChERS-气相色谱-串联质谱法测定鸡蛋中氟虫腈及其代谢产物

目的建立QuEChERS-气相色谱-串联质谱同时测定鸡蛋中氟虫腈及其代谢产物的方法。方法于5.0 g鸡蛋样品中加入3 ml水,加入10 ml乙腈提取,提取液经EMR-Lipids管净化。采用DB-5MS(30 m×0.25 mm,0.25μm)进行分离,多反应监测(MRM)模式进行检测,基质匹配曲线外标法定量。结果氟虫腈及其代谢产物在0～60μg/L范围内线性良好,相关系数(r)均≥0.999 0,检出限(S/N=3)为0.5～0.8μg/kg,定量限(S/N=10)为1.7～2.7μg/kg。回收率为92.0%～115.5%,相对标准偏差(RSD)为3.6%～6.8%(n=6)。结论该方法具有前处理方法简单、灵敏度高、回收率高等特点,适用于鸡蛋中氟虫腈及其代谢产物的准确检测。     

气相色谱-负化学源-质谱法测定茶叶中的氟虫腈及其代谢物

建立气相色谱-负化学源-质谱法测定茶叶中氟虫腈及其代谢物：氟甲腈、氟虫腈砜和氟虫腈亚砜。采用乙腈提取茶叶中的氟虫腈及其代谢物，并通过正己烷液液分配后，经PSA-SPE柱净化。采用气相色谱-负化学源-质谱法进行氟虫腈及其代谢物的检测，外标法定量。结果表明，茶叶中的氟虫腈及其代谢物在16 min内被分离。方法中4种目标物的线性范围为0.002～0.200?μg/mL，相关系数R²>0.999，检出限(R_SN=10)为0.002 mg/kg，相对标准偏差低于5%。在添加量为0.002、0.010 mg/kg和0.020 mg/kg时，加标回收率在96.33%～102.50%之间。本方法线性范围广、准确性高、重复性好，可以快速准确地对市售茶叶中氟虫腈及其代谢物进行痕量检测分析。     

液相色谱-串联质谱法测定猪肉中氟虫腈及其代谢物残留

目的建立一种测定猪肉中氟虫腈及其3种代谢产物(氟甲腈、氟虫腈硫醚及氟虫腈砜)的液相色谱-串联质谱方法。方法样品经乙腈提取后,经固相萃取柱去除基质中的脂质干扰物,液相色谱分离,串联四极杆质谱定量测定,选择性反应监测模式检测。结果 4种待测组分均获得足够的色谱保留和分离,各药物在0.5~10.0μg/kg范围内呈现良好的线性关系,日内日间精密度小于15%,方法回收率在85%~115%之间,方法的定量限为0.5μg/kg。结论此方法快速、准确且灵敏度高,为监测猪肉中的氟虫腈提供了准确有效的技术手段。     

QuEChERS-高效液相色谱-串联质谱法快速测定鸡肉中氟虫腈及其代谢物

建立一种QuEChERS-高效液相色谱-串联质谱法,快速测定鸡肉中氟虫腈及其3种代谢产物(氟甲腈、氟虫腈砜及氟虫腈亚砜)的方法。鸡肉样品经乙腈分散,DisQuE提取管提取和DisQuE净化管净化后,采用液相色谱-串联质谱定量测定,选择性多反应监测模式检测。在0.5~20ng/mL线性范围内,氟虫腈及其代谢产物的回归方程均呈良好的线性关系,R2>0.999,在添加水平为1.0、5.0、10.0μg/kg时,平均回收率为75.2%~89.9%,相对标准偏差(RSD)为0.8%~9.2%,方法检出限为0.5μg/kg,定量限为1.0μg/kg。该方法简便快捷,灵敏度和准确度均较高,精密度较好,适用于鸡肉中氟虫腈及其代谢产物残留量的检测。     

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.     

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.     

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.     

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.