QuEChERS-超高效液相色谱-串联质谱法同时测定水产品中20种苯并咪唑类药物及其代谢物残留

目的 建立QuEChERS结合超高效液相色谱-串联质谱法(ultra performance liquid chromatography -tandem mass spectrometry, UPLC-MS/MS)同时快速测定水产品中20种苯并咪唑类药物及其代谢物残留量的分析方法。方法 样品经乙腈提取, 用乙二胺-N-丙基甲硅烷(primary secondary amine, PSA)和中性氧化铝吸附剂净化, 通过Waters ACQUITY UPLC HSS T3 (2.1 mm×100 mm, 1.8 μm)色谱柱分离, 以0.1%甲酸水溶液-乙腈为流动相, 采用电喷雾正离子模式下, 多反应监测(multiple reaction monitoring, MRM)模式下分析, 基质匹配曲线外标法定量。结果 20种苯并咪唑类药物及其代谢物在0.05~20.00 μg/L范围内线性关系良好(r2≥0.9991), 在空白样品基质中进行3个不同浓度水平的加标实验, 平均回收率为63.3%~105.8%, 相对标准偏差为0.1%~7.5% (n=6)。方法检出限为0.1~0.5 μg/kg, 定量限为0.3~2.0 μg/kg。结论 该方法操作简便、灵敏度高、准确可靠, 适用于水产品中20种苯并咪唑类药物及其代谢物的快速筛查。     

QuEChERS-UPLC-MS/MS法测定鸡蛋中19种氨基甲酸酯类农药及其代谢物残留量

采用QuEChERS-超高效液相色谱-串联质谱法（UPLC-MS/MS）同时测定鸡蛋中的19种氨基甲酸酯类农药及其代谢物残留量。鸡蛋样品通过乙腈提取,分散固相萃取净化,UPLC-MS/MS测定。19种氨基甲酸酯类农药及其代谢物残留在0.2~50 ng/mL范围内线性良好（R2>0.999）,方法的检出限为1.0~10 μg/kg。在添加水平为10、20、50 μg/kg时,回收率为69.3%~107.6%,相对标准偏差低于9.21%。该方法简单快速,高效准确,回收率高,能够满足鸡蛋中19种氨基甲酸酯类农药及其代谢物残留检测与确证的需要。     

高效液相色谱-串联质谱法测定乳制品中的莫奈太尔及其代谢物

建立测定乳制品中莫奈太尔及其代谢物的高效液相色谱-串联质谱法。试样加水-饱和氯化钠-乙腈溶液提取,正己烷净化,经Inertsil C8（2.1 mm×100 mm,3 μm）色谱柱分离,以甲醇-0.5 mmol/L乙酸铵溶液为流动相进行梯度洗脱,采用电喷雾离子源串联质谱,在负离子扫描方式下以多反应监测模式检测,外标法定量。结果表明：莫奈太尔及其代谢物在0.1～5.0 μg/L范围内线性关系良好,定量限为2.0 μg/kg。在3 个加标水平下的平均回收率为79.5%～102.9%,相对标准偏差为2.0%～5.3%。该方法操作简便、快速、准确、灵敏度高、抗干扰能力强、回收率和重复性良好,适合于乳制品中莫奈太尔及其代谢物的测定。     

QuEChERS-高效液相色谱-串联质谱法 测定苹果中丁醚脲及其代谢物残留量

目的 建立基于QuEChERS-高效液相色谱-串联质谱测定苹果中的丁醚脲及其代谢物丁醚脲-脲和丁醚脲-甲酰胺残留量的方法。方法 样品经乙腈提取后用PSA作为固相分散萃取剂净化除杂, 以0.1%甲酸乙腈溶液和0.1%甲酸水溶液(含10 mmol/L甲酸铵)为流动相进行梯度洗脱, 高效液相色谱-串联质谱法正离子多反应监测模式(MRM)测定。结果 丁醚脲及其代谢物在5~100 μg/L的范围内有良好的线性, 相关系数(R2)>0.999。定量限5 μg/kg为以空白苹果为基质, 在5、10、50 μg/kg三个水平的加标回收率范围在78.3%~103.1%之间, 精密度在2.1%~8.2%之间。结论 该方法前处理快速简单, 可用于对进出口的苹果中丁醚脲及其代谢物的检测。     

超高效液相色谱-串联质谱法测定乳及乳制品中青霉素类药物残留量

建立了超高压液相色谱-串联质谱法(UPLC-MS/MS)测定乳及乳制品中青霉素类药物残留量的方法。利用UPLC-MS/MS外标法进行样品中青霉素类药物的测定。乳制品经乙腈、乙酸锌、盐酸溶液提取,样品再经HLB固相萃取柱富集净化后,进行UPLC-MS/MS检测。结果表明,10种青霉素在1~50 ng/mL范围呈良好线性,线性相关系数大于0.9991。牛奶的平均回收率为88.8%~92.0%,测定结果的相对标准偏差为1%~7%;奶粉的平均回收率在88.7%~91.3%之间,相对标准偏差为5%~11%。研究表明,该方法操作简便、快速、灵敏度高,适用于牛奶和奶粉中10种青霉素类抗生素残留的同时测定。     

基于质谱特征碎裂片段的巴氏杀菌乳中氯化烟碱类药物及其代谢产物非定向筛查方法构建

该研究利用超高效液相色谱-四极杆-静电场轨道离子阱高分辨质谱技术,对12种氯化烟碱类药物及其代谢产物色谱信息、分子离子质荷比和二级碎裂片段的质荷比进行采集,解析了碎裂途径,建立了氯化烟碱类药物及其代谢产物标准数据库,筛选特征碎裂片段;采用数据非依赖扫描模式,获取可追溯的样品质谱信息,构建了乳制品中氯化烟碱类药物及其代谢产物的非定向筛查方法。该方法确定限和检测容量分别为0.01 μg/kg~0.33 μg/kg与0.03 μg/kg~0.59 μg/kg,回收率为84%~104%,其相对标准偏差为4.4%~7.1%。将所建立的方法用于81个批次巴氏杀菌乳中氯化烟碱类药物及其代谢产物的筛查工作当中,发现样品中含有未检出的啶虫脒-代谢物-IM-1-4,含量为0.32 μg/kg。结果显示该方法快速、简便,可实现乳制品中氯化烟碱类药物及其代谢产物准确定性和精准定量。     

液相色谱-串联质谱法检测蜂蜜中氟苯尼考及其代谢物残留量

目的 建立液相色谱-串联质谱法检测蜂蜜中氟苯尼考及其代谢物残留量的分析方法。方法 样品经氨化乙酸乙酯提取,通过DPC-2固相萃取柱净化,采用Poroshell 120 EC-C18柱分离,以10 mmol/L乙酸铵溶液-乙腈为流动相进行梯度洗脱,电喷雾正/负离子切换,多反应监测模式检测,同位素内标法定量。结果 氟苯尼考在0.2～30 μg/L时具有良好的线性关系,相关系数大于0.999,检出限为0.05 μg/kg,回收率为85.5%~116.3%,相对标准偏差小于10%。氟苯尼考胺在1～30 μg/L时具有良好的线性关系,相关系数大于0.999,检出限为0.3 μg/kg,回收率为85.6%~113.5%,相对标准偏差小于10%。结论 该方法快速、准确、灵敏, 适用于蜂蜜中氟苯尼考及其代谢物残留量的测定。     

空间位阻净化-超高效液相色谱-串联质谱技术测定动物源性食品中抗组胺类药物残留

建立超高效液相色谱-串联质谱法快速测定动物源性食品中19 种抗组胺类药物及其代谢物残留的方法。样品用乙腈-乙酸乙酯溶液提取,提取液经空间位阻净化吸附剂EMR净化,再经无水硫酸镁和氯化钠盐析并浓缩后测定,以0.1%甲酸和0.1%甲酸-乙腈作为流动相进行梯度洗脱,在Poroshell 120 EC-C18色谱柱（100 mm×2.1 mm,2.7 μm）上分离,柱温35 ℃,流速0.3 mL/min,进样量10 μL,在电喷雾正离子模式下以动态多反应监测采集数据,外标法定量。结果表明,19 种抗组胺类药物及其代谢物在相应质量浓度范围内线性良好,相关系数均大于0.999,不同阴性样品基质中（牛肉、鸡肉、猪肝）在3 个质量浓度水平加标实验回收率在75.1%～89.1%之间,相对标准偏差为2.3%～7.1%,方法检出限为0.2～2.0 μg/kg,定量限为0.6～6.0 μg/kg。经方法学验证,本方法简便快速、重复性好、灵敏度高、结果可靠。适用于动物源性食品中19 种抗组胺类药物及其代谢物的快速筛查和定量测定。     

固相萃取-UPLC-MS/MS法测定牛奶中氟虫腈及其代谢物残留量

建立一种固相萃取-超高效液相色谱-串联质谱法同时测定牛奶中氟虫腈及其代谢物(氟甲腈、氟虫腈砜、氟虫腈硫醚)的分析方法。牛奶样品经提取和盐析,Oasis PRiME HLB固相萃取柱通过式净化后,以乙腈-水为流动相,HSS T3色谱柱(2.1mm×100 mm,1.8 μm)进行色谱分离,在电喷雾负离子模式下,多反应监测(MRM)方式进行测定,外标法定量。结果表明,氟虫腈及其代谢物在0.05~5.0 μg/L浓度范围内均呈良好的线性关系,相关系数r≥0.9976,方法检出限为0.01 μg/kg,定量限为0.05 μg/kg。在浓度分别为0.5、1、10 μg/kg加标水平下,4种化合物的回收率范围为80.6%~101%,相对标准偏差范围为1.0%~6.1%。该方法简单快捷、准确可靠,适用于牛奶中氟虫腈及其代谢物的同时测定。     

高效液相色谱法同时测定动物组织中16 种苯并咪唑类药物残留

建立同时测定动物组织中16 种苯并咪唑类药物及其代谢物多残留的高效液相色谱分析方法。试样经乙酸乙酯、50g/100mL 氢氧化钾溶液、1g/100mL BHT 溶液(20+0.15+1,V/V)提取后,正己烷脱脂,MCX 固相萃取柱净化,用高效液相色谱C18 柱分离,乙腈-0.025mol/L 乙酸铵作为流动相,流速为1.0mL/min,梯度洗脱,紫外检测波长为292nm,外标法峰面积定量。16 种苯并咪唑类药物在0.025～1.0mg/L 质量浓度范围内线性良好,相关系数r 均大于0.99,动物组织样品在10、50、100μg/kg 添加水平的添加回收率在81.6%～110% 之间,相对标准偏差为1.8%～13.1%(n=10),方法的定量限为10μg/kg。方法灵敏度高、重现性好,适用于动物组织中苯并咪唑类药物多残留的检测。     

光谱技术在乳及乳制品研究中的应用进展

文章阐述了光谱技术在乳及乳制品掺假和掺伪检测、营养成分检测、抗生素检测、微生物污染检测,乳及乳制品种类的鉴定等方面的应用。综述了近红外光谱、拉曼光谱、高光谱成像技术在乳及乳制品品质检测和安全评定上的重要应用和研究进展,指出多种技术联合应用是未来研究的趋势。     

亚洲奶业与中国市场发展态势研究

一个国家奶业发展得如何？往往是被作为评价一个国家的农牧业发达程度的一个重要标志。发展中国家特别是亚洲国家近年来也把发展奶业作为提高国民营养水平和民族素质，促进经济发展的重要措施来抓。亚太地区大部分国家的奶业目前仍处于发展初级阶段或萌芽状态，中国正处于发展中。不过，这正是亚洲在全球奶品市场中最显潜力和最具有市场发展空间的一个潜在市场特征所在，亚洲乳品市场是一个正在快速发展而又存在着巨大潜力的市场。扩大消费，积极培育市场和可持续发展，是亚太地区各国及其奶业界需要加于研究的重要课题。把关注奶业发展的焦点聚焦于亚太奶业，开展对这一地区奶业状况及其发展前景与趋势的研究，是一件非常有意义的事情。2007年5月29日，在第六届中国（广州）国际乳业发展高峰论坛上，有中国奶业“泰斗”之称的广东省奶业协会副会长王丁棉就“亚洲奶业与中国市场发展态势研究”作了专题演讲，得到与会嘉宾的一致好评，在此我们节略其中精彩片段，相信奶业界的同仁以及拟将在这一地区进行奶业投资的投资者，对这一选题会感兴趣。     

增强质量意识全面实施安全性乳与乳制品生产体系

根据发达国家食品生产的发展趋势，结合我国入世形势和发展需要，论述了安全性乳与乳制品的重要性，评价及其不安全因素的来源，提出在乳制品生产过程中建立完善的安全控制体系。     

Functional milks and dairy beverages

During the last decade, consumers' approach to healthy foods has changed dramatically, and today enhancing the health span of consumers through consumption of healthy food is more important than simply enhancing their life span. Rising medical costs are the prime factor forcing people to find cheaper and effective means of protecting their health. This fact has led to an increase in consumers' interest in functional foods. Dairy products occupy a significant space in the functional foods market and dairy-based functional beverages are a growing segment of this sector. This article reviews recent scientific, technological and commercial developments in the functional dairy-based beverage sector.     

世界奶类和奶制品形势分析

据联合国粮农组织（ＦＡＯ）的分析,２００１年世界奶类产量继续增长,奶制品进口需求稳定,奶制品出口价格上涨。 １．奶类产量继续增长１９９８～２００１年４年来,世界奶类产量连年增长。２００１年全球奶类产量将比上年增长２％,达到５．８５亿吨,比上年增加９００万吨。大洋洲的新西兰近三年奶产量维持在１２００万吨,比１９９８年增加１００万吨;澳大利亚近３年奶产量维持在１１００万吨,比１９９８年增加１００万吨。美国奶类产量近４年来平稳增长,２００１年将达到７ ６４０万吨。东欧２００１年奶类产量将比上年增长。欧共…     

Exploring farmers' attitudes and determinants of dairy calf welfare in an expanding dairy sector

The 2015 European Union milk quota abolition initiated considerable expansion in the dairy sector in many European Union countries, most significantly in Ireland. However, this major production increase also had wider societal implications, such as negative environmental and animal welfare consequences. In this article, we used survey data of 441 Irish dairy farmers to assess farmers' attitudes toward the welfare of farmed animals and dairy calves, as well as the reputation of the Irish dairy sector. We also explored how expansion, breeding, calf management, and farmer characteristics relate to calf welfare outcomes (i.e., calf mortality, calf export, and premature culling). In relation to attitudes, farmers expressed a general concern toward animal welfare, while views toward dairy calves and industry reputation were mixed. We used Ward's linkage hierarchical cluster analysis to group farmers based on their attitudes. The cluster analysis revealed 3 distinct groups relating to high, medium, and low animal welfare concern. Herd expansion was negatively associated with being in a higher animal welfare concern cluster, whereas beef trait–focused breeding was positively associated with it. In relation to dairy calf welfare outcomes, our econometric analyses based on multiple regression and binary choice models revealed that expansion was positively associated with calf mortality, whereas improved breeding and calf management factors had a negative association. In addition, being in the high animal welfare concern cluster was negatively associated with calf mortality. Furthermore, breeding decisions were significantly associated with whether calves were exported, and being in the high animal welfare concern cluster was negatively associated with the probability that calves were sent for live export. Finally, farmers' breeding and calf management decisions were associated with premature culling of calves. Overall, this article revealed strategies worth promoting to improve dairy calf welfare, such as beef trait–focused breeding leading to greater dairy-beef integration.     

Survey of preweaning dairy calf-rearing practices in Czech dairy herds

It is important to describe weaknesses in rearing calves not only to improve their welfare, but also to detect areas where current scientific knowledge is poorly integrated into practice. A survey of preweaning calf-rearing practices was conducted using a farmer questionnaire. The survey included 136 farms, representing 11.9% of all dairy cows in the Czech Republic. Mean herd size (± standard deviation) was 326 ± 131.4 cows, and mean milk production 7,413 ± 1,389.5 kg per cow per year. We evaluated 59 farms with Holsteins (H) and 77 with the Czech Fleckvieh breed (C). The survey revealed that (1) calving in group pens predominated (67.6% of farms); (2) no disinfection of calf navels occurred on 11.8% of herds; (3) pooled colostrum was fed on 15.4% of farms; (4) colostrum quality was controlled on only 44.1% of farms, and only 73.5% of farms had reserve colostrum stocks; (5) nonmarket waste milk was fed in 64.7% of herds but it was pasteurized in only in 6.8% of herds and acidified in 35.2% of herds; (6) milk replacer was mixed with nonmarket waste milk on 52.9% of farms; (7) 58.8% of farms enabled calves to obtain milk by sucking and 41.2% by drinking from a bucket; (8) the main criterion in weaning was calf age (61.7%), followed by acceptance of starter and concentrated feed (19.9%) and lack of housing capacity (18.4%); and (9) newborn calves were individually housed on 96.7% of farms and group-housed on 3.3% of farms. The most marked differences in calf-rearing management between Holstein and Czech Fleckvieh farms were (1) a higher proportion of operations calving in tie-stalls or stanchions in C (6.5%) versus H (1.7%) farms; (2) a higher proportion of untreated navels on C (15.6%) versus H (6.8%) farms; (3) a lower proportion of C (11.7%) versus H (20.4%) farms feeding pooled colostrum; (4) a lower proportion of C (39%) versus H (50.9%) farms monitoring colostrum quality; (5) sucking milk from nipple buckets predominated (61%) on C farms, whereas drinking from an open bucket was most common (64.4%) on H farms; (6) age was the main criterion in weaning calves of both breeds (C farms: 55.8%, H farms: 69.5%), whereas the second most important criterion was lack of housing capacity (28.6% of farms) on C farms and the amount of consumed starter (25.4%) on H farms. We observed a difference in duration of colostrum period between C herds (median 5 d) and H herds (median 4 d). A tendency was observed for age of calves at weaning (C herds: median at 9.1 wk, H herds: median at 10 wk).     

The shelf-life of dairy products: 4. Intermediate and long life dairy products

In the fourth and final part of this series of broad reviews, the factors controlling the shelf-life of selected intermediate and long life dairy products are discussed. Although the extent of contamination of the raw material by psychrotrophic bacteria is relevant, in contrast to short shelf-life products microbial contamination is of secondary importance to chemical change. Lipid oxidation, Maillard reaction and calcium induced aggregation may all limit shelf-life. Examples of susceptible dairy products have been chosen and methods for extending shelf-life are discussed. It is clear that no common strategy exists and optimization of shelf-life must be carried out on a product by product basis.     

构建和谐奶业环境 加快现代奶业建设

<正> 中国奶业协会于2007年6月21～23日在江苏南京召开。本次会议的主题是"乳品企业健康发展与和谐奶业建设。"会议坚持科学发展观,对当前奶业发展形势进行了分析,对落实全国奶业"十一五"发展规划和推进现代奶业建设展开了广泛交流。农业部畜牧司副司长陈伟生出席大会,并作了重要讲话。中国奶业协会理事长刘成果在大会上作了"促进乳品企业健康发展构建和谐奶业"的主题报告。会议认为,当前我国奶业形势总体是好的,向健康方向发展     

益生菌制剂及其发酵性乳制品

综述了益生菌的概念和益生菌菌株的选择标准、国外益生菌产品的发展状况、益生菌作为新型酸奶发酵剂的使用情况，以及益生酸奶的生产与消费情况。