SPE-GC/MS外标法测定水产品中4种丁香酚类麻醉剂

建立了固相萃取/气相色谱-质谱法(GC-MS)测定水产品中4种丁香酚类(丁香酚、异丁香酚、甲基丁香酚和甲基异丁香酚)麻醉剂的分析方法。样品采用正己烷-丙酮混合液(3:1,v/v)提取,乙二胺-N-丙基硅烷(PSA)净化,浓缩后再经硅胶固相萃取柱净化,采用GC-MS测定,外标法定量。结果表明:4种丁香酚类麻醉剂在5.0~200 ng/mL范围内均呈现良好线性关系,相关系数均大于0.998,方法检出限(S/N=3)均为3.0 μg/kg,方法定量限(S/N=10)均为10.0 μg/kg。空白水产品样品在0.01、0.05、0.20 mg/kg等3个加标水平时,4种目标物的平均加标回收率为85.7%~102.5%,相对标准偏差(RSD)为3.3%~9.8%。此方法净化效果较好,灵敏度高,适合水产品中4种丁香酚类麻醉剂的定性和定量分析。     

分散固相萃取-气相色谱法同时测定水产品中六种丁香酚类麻醉剂的残留量

建立了同时检测水产品中六种丁香酚类麻醉剂残留量的分散固相萃取-气相色谱检测方法。样品经丙酮进行提取,旋转蒸发浓缩后定容,采用分散固相萃取(DSPE)净化,用气相色谱仪进行测定,外标法定量。六种丁香酚类化合物在0.05~10.0μg/m L的浓度范围内线性关系良好,相关系数R2为0.9995~0.9999。又分别在罗非鱼、南美白对虾、鳗鲡以及梭子蟹肌肉样品中添加0.1~1.0mg/kg的混合标准溶液,测定平均回收率在80.3%~103.2%范围内,相对标准偏差在0.7%~5.4%之间。方法的定量限(LOQ),六种丁香酚类化合物(丁香酚、甲基丁香酚、异丁香酚、甲基异丁香酚、乙酸丁香酚酯、乙酰基异丁香酚)均为0.1mg/kg。     

GC-MS法同时测定水产品中6种丁香酚类麻醉剂的残留量

建立了同时检测水产品中6种丁香酚类麻醉剂残留量的气相色谱-质谱(GC-MS)检测方法。样品经乙腈超声提取,分散固相萃取净化后氮吹浓缩、定容,用气相色谱-质谱仪进行测定,外标法定量。6种丁香酚类化合物在1.0~200.0 μg/L的浓度范围内线性关系良好,相关系数R~2为0.9956~0.9995。又分别在罗非鱼、南美白对虾以及扇贝肌肉样品中添加1.0~10.0 μg/kg的混合标准溶液,测定平均回收率在82.2%~100.7%范围内,相对标准偏差在0.6%~7.4%之间。方法的定量限(LOQ),丁香酚、甲基丁香酚、异丁香酚、乙酰基异丁香酚为1.0 μg/kg,甲基异丁香酚和乙酸丁香酚酯为0.5 μg/kg。     

固相萃取-高效液相色谱-荧光检测法测定水产品中4种丁香酚类化合物

目的建立固相萃取-高效液相色谱荧光法测定水产品中4种丁香酚类化合物(丁香酚、异丁香酚、甲基丁香酚、甲基异丁香酚)残留的方法。方法样品用乙腈提取,中性氧化铝和C18固相萃取柱净化,Inertsil ODS-SP C18柱(4.6 mm×250 mm,5μm)分离,以甲醇-乙腈(1∶1,V/V)和1%冰乙酸水溶液为流动相,荧光检测激发波长为280 nm,发射波长为320 nm,外标法定量。结果 4种丁香酚类化合物在各自范围内线性关系良好,相关系数均0.999,方法检出限为3.0~6.0μg/kg,方法定量限为10.0~20.0μg/kg,平均加标回收率为74.7%~103.0%,相对标准偏差(RSD)为2.6%~8.1%。结论本方法操作简便、灵敏度高、实用性强,适用于水产品中丁香酚、异丁香酚、甲基丁香酚、甲基异丁香酚的残留分析检测。     

固相萃取-超高效液相色谱串联质谱法测定牛奶中6种头孢菌素类抗生素

目的建立固相萃取超高效液相色谱串联质谱(SPE-UPLC-MS/MS)同时检测牛奶中6种头孢菌素类抗生素含量的方法。方法样品经0.05 mol/L的磷酸氢二钾缓冲溶液提取,HLB固相萃取柱净化,液相色谱串联质谱法测定,采用多反应监测模式进行定性和定量分析。结果 6种头孢菌素类抗生素的检出限(S/N=3)和定量限(S/N=10)范围分别为0.05~0.4μg/kg和0.1~1.6μg/kg。样品加标回收率范围为66.3%~110.0%。结论该方法便捷、快速、高效,能够满足牛奶中头孢菌素类抗生素的检测。     

QuEChERS-高效液相色谱法同时测定植物固体饮料中10种植物毒素

建立了植物固体饮料中原百部碱、侧柏酮、香豆素、黄连素、黄樟素、山道年、芦荟苷、细辛脑、异黄樟素、长叶薄荷酮10种植物毒素的QuEChERS结合超高效液相色谱的检测方法。样品经乙腈提取,应用QuEChERS技术净化,Wlech Xtimate C_8液相色谱柱(4.6mm×250mm,5μm)分离,流动相为甲醇-10 mmol/L乙酸铵水溶液(pH 3.5),通过PDA检测器进行检测。试验表明,10种植物毒素在0.005～154.200mg/L范围内线性关系良好,相关系数均0.997,方法检出限(S/N=3)为0.010～0.270mg/kg,定量限(S/N=10)为0.032～0.830mg/kg。阴性样品的3个添加水平的平均回收率在78.46%～100.77%,相对标准偏差(RSD,n=6)1.10%～3.07%,日间精密度为1.11%～2.73%。该方法操作简单,准确高效,适用于植物固体饮料种10种植物毒素含量的测定。     

高效液相色谱同时测定植物饮料中7种植物毒素

建立了同时检测植物饮料中原百部碱、香豆素、黄连素、山道年、细辛脑、长叶薄荷酮和芦荟苷A 7种植物毒素含量的高效液相色谱法。试样经HLB固相萃柱富集净化,甲醇洗脱,氮吹浓缩后用流动相起始梯度定容至1.0 mL,经Welch Ultimate XB-C18色谱柱（4.6 mm×150 mm,5 μm）分离,以甲醇-10 mmol/L乙酸铵水溶液（pH=3）为流动相梯度洗脱,通过紫外检测器进行检测。7种植物毒素化合物在0.20～100.00 mg/L范围内线性关系良好,相关系数均＞0.99,方法的检出限分别为0.2～6.5 μg/kg,定量限为0.8～21.6 μg/kg。分别对3种植物饮料样品进行加标回收率实验,回收率为67.1%～104.0%,相对标准偏差（n=6）为1.08%～5.12%。该方法操作简单,具有较高的准确度和精密度,适用于植物饮料中7种植物毒素含量的检测。     

超声萃取-气相色谱-质谱法测定烟用水基胶中的5种异噻唑啉酮杀菌剂

建立了超声萃取-气相色谱-质谱联用同时检测烟用水基胶中5种异噻唑啉酮杀菌剂的分析方法。烟用水基胶样品经二氯甲烷超声萃取30 min,静置取上清液并加入N,O-双(三甲基硅烷)三氟乙酰胺(BSTFA)衍生后进行GC-MS选择离子分析,内标法定量。结果表明:5种异噻唑啉酮待测化合物在0.40~16.00μg/m L范围内线性关系良好,R2为0.9973~0.9997;检出限(LOD)和定量限(LOQ)分别为0.004~0.15μg/m L和0.018~0.050μg/m L,回收率为90.2%~99.1%,相对标准偏差RSD为1.7%~5.7%。该方法具有简单、准确、灵敏等特点,应用于实际样品检测取得了良好效果。     

全自动固相萃取-高效液相色谱-串联质谱法测定 蜂蜜中3种农药残留

目的建立蜂蜜中多菌灵、甲基托布津和乙基托布津3种农药的全自动固相萃取-高效液相色谱-串联质谱检测方法。方法蜂蜜样品经磷酸盐缓冲液(pH=7.8)溶解,稀释,全自动固相萃取净化后,采用高效液相色谱-串联质谱测定,内标法定量。结果 3种农药在2~100μg/L范围内呈良好的线性关系(r~20.99),定量限为5μg/kg。在5.0、10.0、20.0μg/kg 3个加标水平下,3种农药的回收率为75.6%~97.1%,相对标准偏差小于13.2%。结论该方法简单、快速,准确度和精密度良好,可用于蜂蜜中多菌灵、甲基托布津和乙基托布津的同时测定。     

气相色谱-串联质谱法测定生姜中的黄樟素

建立了固相萃取净化结合气相色谱-质谱联用仪测定生姜中的黄樟素的分析方法。实验优化了样品前处理条件和色谱质谱条件。样品经乙腈提取,高速离心后,采用Carb-NH_2固相小柱富集净化,洗脱液经旋转蒸发仪浓缩。采用气相色谱分离,多反应离子监测模式(MRM)进行黄樟素质谱检测。以基质匹配标准溶液外标法定量测定。实验结果表明,黄樟素在0.005～0.5μg/mL范围内呈良好的线性关系,相关系数(R~2)大于0.999,方法检出限(S/N=3)为0.42μg/kg,定量限(S/N=10)为1.41μg/kg,在5、25、50μg/kg 3个添加水平下,样品中黄樟素的平均回收率为107.7%～111.9%,相对标准偏差为2.02%～2.32%。该方法具有灵敏度高、富集效果好、回收率高等优点,为生姜及其生姜制品中的黄樟素筛查提供技术支持。用本研究建立的方法检测151个生姜样品,发现部分生姜样品中有微量黄樟素检出,浓度范围为0.45～1.3μg/kg。     

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.