酶联免疫法(ELISA)检测饲料中黄曲霉毒素B1

本文介绍了利用ELISA法的黄曲霉毒素B1(AFB1)试剂盒测定饲料中黄曲霉毒素B1的含量。样品经处理后,用甲醇水溶液提取饲料中黄曲霉毒素,提取液经过过滤、稀释后,用酶联免疫法直接测定。加标回收测定,平均加标回收率89%～93%,用酶联免疫法进行定性、定量测定,其特异性强,分析速度快,污染小,简化提取和纯化步骤,结果易判读。     

ELISA法检测配合饲料呕吐毒素前处理方法的研究

对配合饲料中用酶联免疫吸附试验(ELISA)法检测呕吐毒素的前处理方法进行研究,通过试验确定最佳提取方法:60％乙腈水溶液振摇80 min、提取、过滤及氯仿净化.该方法平均回收率为85.3％～91.1％,相对偏差(n=6)为2.4％～4.9％.该方法在有效提取毒素的同时消除干扰因素形成的结果误差,可为配合饲料中呕吐毒素的准确定量检测提供有效手段.     

ELISA和TLC检测饲料中AFB1含量的比较研究

[目的]研究酶联免疫吸附法和薄层色谱法的特点,比较2种方法检测黄曲霉毒素B1含量的优缺点.[方法]酶联免疫吸附法采用黄曲霉毒素B1酶联免疫定量测试盒对饲料中黄曲霉毒素B1的含量进行测定;薄层色谱法应用薄层荧光扫描测定黄曲霉毒素B1的含量,并用薄层色谱进行确证试验.[结果]酶联免疫吸附法测定黄曲霉毒素B1含量的标准曲线r值为0.999 3～0.999 9,变异系数为0.3％～0.6％,回收率在94.0％ ～105.0％之间.薄层色谱为半定量色谱,但该试验利用荧光扫描法测定黄曲霉毒素B1的含量,标准曲线r值为0.998 1,回收率在84.60％～90.08％之间.[结论]2种方法相比较,薄层色谱法是传统经典的方法,具有抗干扰能力强、离线检测可反复测试的优点,但TLC法前处理较为麻烦,精密度、回收率均没有酶联免疫吸附法高;ELISA法是目前国际检测AFB1的先进方法,具有灵敏度高、干扰少、简便快速、操作安全等优点.     

酶联免疫吸附(ELISA)法检测饲料中黄曲毒素B1的探讨

利用三氯甲烷对黄曲毒素B1有较强选择性作用的特点，用它作为黄曲毒素B1的提取液，对浓缩饲料和成分较复杂的配混合饲料进行纯化处理，使测试结果的准确性与重复性都得到提高，取得令人满意的结果。     

锦阳市饲料黄曲霉毒素B1污染情况调查

本次调查利用固相酶联免疫吸附(ELISA)原理,对在四川省绵阳市生产、销售、使用的饲料产品进行抽样,取得155份样品进行黄曲霉毒素B1含量检测.结果表明,绵阳市饲料黄曲霉毒素B1检出率为100％,总体超标率为3.9％,但乳(仔)猪饲料黄曲霉毒素B1超标率为6.2％,相对其他类型饲料较高,方差分析显示配合饲料与浓缩饲料的黄曲霉毒素B1污染情况差异显著(P＜0.05).     

螯合剂在ELISA检测饲料中黄曲霉毒素B_1上的应用研究

<正>在饲料生产上,以无机盐形式添加来满足畜禽的微量元素需要仍为主要手段。目前必需微量元素添加剂的不科学补充主要表现为超量添加,尤其在配合饲料中使用高铜、高锌和高铁制剂。由此带来的霉菌毒     

西南地区猪配合饲料中黄曲霉毒素B_1的污染调查

本研究旨在调查中国西南5省市猪配合饲料中黄曲霉毒素B1的污染分布情况,为实际生产提供一定参考和理论依据。采用酶联免疫吸附法(ELISA)对来自西南不同地区、不同企业规模的猪配合饲料样品(共205份)进行试剂盒初筛,将AFB1含量超过国家限量标准80%以上的样品进行高效液相色谱法(HPLC)确认,选择两种方法所测结果差异较大的样品用高效液相色谱-质谱联用法(HPLC-MS)复查,分析各种方法所测得的试验结果,获得试验最终数据。从不同地区看,贵州省的饲料样品AFB1全检出,但超标率为0;云南省的样品检出率最低,为44.12%,所有样品均未超标;其余三省市(四川、重庆、广西)的饲料样品检出率均在72%~73%,超标率不超过10%。从企业规模看,小规模企业(年产2万t~5万t)AFB1检出率最高,为72.22%,稍高于中等企业规模(年产5万t~10万t)和大规模企业(年产大于10万t);超标率方面,小、中、大规模生产企业样品中AFB1超标率分别为7.41%、3.17%和1.14%。从不同生理阶段的饲料看,仔猪料和后备母猪料受AFB1污染不显著(P0.05),但检出率均较高。调查结果提示:不同地区、不同规模的饲料生产企业以及不同生理阶段的猪配合饲料均受到不同程度的AFB1污染,饲料质量安全问题不容忽视。     

我国饲料中黄曲霉毒素B_1污染的分布规律研究

采用酶联免疫(ELISA)法测定全国11个省份共计1013份饲料样品中黄曲霉毒素B1含量,了解我国饲料中黄曲霉毒素B1污染情况及分布规律。结果表明,饲料中黄曲霉毒素B1检出率高达99.51%,但超标率较低,平均为2.27%;不同省份饲料中黄曲霉毒素B1含量差异极显著(P<0.01),贵州省最高,河南省、四川省较高,福建省最低,其余7省居中;黄曲霉毒素B1含量由高到低依次为棉粕、家禽配合饲料、菜粕、玉米、仔猪配合饲料、麦麸、豆粕、鱼粉和小麦。我国饲料普遍受到黄曲霉毒素B1的污染,但饲料原料中黄曲霉毒素B1的超标率低,含量在不同区域和饲料种类间存在差异。     

饲料中黄曲霉毒素 B_1的简易定性测定

<正> 黄曲霉毒素是强烈致癌物质。1960年,英国曾发生震惊世界的10万只火鸡因食用含有黄曲霉毒素的饲料而中毒死亡事件。目前,已分离出10多种黄曲霉毒素异构体。其中最常见、毒性最大的是黄曲霉毒素B_1。因此,对饲料中黄曲霉毒素 B_1进行检测不仅很有必要,而且很有代表性。当今。在对外贸易合同中。对饲料中黄曲霉毒素 B_1要求不得检出。肉眼在紫外光下可观察到的最低限度为5ppb,如果观察不到,可认为未检出。     

有机相萃取法消除ELISA检测AFB1假阳性的研究

近年来，饲料质量检验部门广泛采用酶联免疫吸附法（ELISA）检测饲料中黄曲霉毒素B1（AFB1）（GB/T17480-1998），但由于目前的饲料产品中添加了一定量的重金属离子及其它营养增强剂，采用国标中的提取方法易出现假阳性结果。利用有机相萃取法可有效地消除假阳性。     

生物法降解黄曲霉毒素B_1的机理研究进展

黄曲霉毒素B_1是由寄生曲霉、黄曲霉等真菌产生的次级代谢物,具有极强的致畸、致癌等毒性,不仅对人和动物健康构成严重的威胁,而且也给食品和饲料工业带来巨大的经济损失。如何消除黄曲霉毒素B_1的污染依然是目前学者迫切要解决的重点问题。相比理化法消除黄曲霉毒素B_1的缺点和局限,生物法降解具有安全、高效和绿色环保等优点,使其成为更具有潜力的解毒方法。本文主要对生物吸附作用和生物酶解作用降解黄曲霉毒素B_1的机理及降解产物的结构分析进行了论述。     

ELISA与HPLC-MS检测玉米中黄曲霉毒素B_1的比较分析

本实验选用30份玉米样品,通过酶联免疫吸附(ELISA)法和高效液相色谱-质谱联用(HPLC-MS)法对玉米中黄曲霉毒素B1含量(AFB1)进行测定比较,得出两种方法的差异性和相关性。其中,使用HPLC-MS外标法定量时,设计两组标准曲线,分别是玉米基质液加标组曲线和纯标组曲线,得到的结果再与ELISA比较。结果显示:用ELISA筛选出的阳性样品,用HPLC-MS法确证亦为阳性,判定结果一致,但具体检出量存在差异。当样品中AFB1含量为2～6μg/kg时,测定结果 HPLC-MS(纯标组)相似文献   

黄曲霉毒素B_1对肉鸡肝线粒体自由基代谢的影响

为观察黄曲霉毒素B1(AFTB1)对肉鸡肝线粒体自由基代谢的影响,并研究亚硒酸钠(Na2SeO3)与复方中药对AFTB1的颉颃效应。10日龄120只试验肉鸡随机分为4组,每组30只,分别为第Ⅰ、Ⅱ、Ⅲ、Ⅳ组,第Ⅰ组为空白对照组;每天以0.2 mg/kg剂量给第Ⅱ、Ⅲ、Ⅳ组肉鸡灌胃投用AFTB11次,并在第Ⅲ组肉鸡基础日粮中添加2%复方中药,在第Ⅳ组肉鸡基础日粮中添加无机硒2 mg/kg(亚硒酸钠),试验期共28 d。并于处理后第17、24、31、38日龄时,检测肉鸡肝线粒体超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性、总抗氧化能力(T-AOC)及丙二醛(MDA)含量变化。结果显示,第Ⅰ、Ⅱ、Ⅲ、Ⅳ组肉鸡肝线粒体SOD、CAT活性及T-AOC均显著降低(P<0.05),线粒体MDA含量显著增高(P<0.05);当投用亚硒酸钠或复方中药后,与第Ⅱ组试验结果比较,第Ⅲ、Ⅳ组肉鸡肝线粒体SOD、CAT活性及T-AOC均显著增强,而线粒体MDA含量明显降低。试验结果表明,在肉鸡日粮中添加亚硒酸钠或复方中药,均能明显缓解AFTB1所致肉鸡肝线粒体抗氧化功能下降的影响,且亚硒酸钠的效果明显优于复方中药。     

酶联免疫法测定饲料中盐酸克仑特罗含量

采用酶联免疫法测定饲料中盐酸克仑特罗的含量。方法的最低检测限为100μg/kg,线性范围0.1～2.7μg/L,r=0.9997。浓度为100、500、1000μg/kg的添加水平时,回收率分别为74％、81％和90％;板内变异系数<15.0％,板间变异系数<14.4％。此方法快速、灵敏、准确、经济,具有实际应用价值。     

Comparative study on the aflatoxin B1 degradation ability of rumen fluid from Holstein steers and Korean native goats

The aflatoxin B1 degrading abilities of two different ruminants were compared in this study. One set of experiments evaluated the aflatoxin B1 degradation ability of different rumen fluid donors (steers vs. goats) as well as the rumen fluid filtration method (cheese cloth filtered vs. 0.45 µm Millipore) in a 2 × 2 factorial arrangement. Additional studies examined aflatoxin B1 degradation by collecting rumen fluid at different times (0, 3, 6, 9 and 12 h) after feeding. Cannulated Holstein steers (740 ± 10 kg bw) and Korean native goats (26 ± 3 kg bw) were fed a 60% timothy and 40% commercial diet with free access to water. Rumen fluid from Korean native goats demonstrated higher (p < 0.01) aflatoxin B1 degradability than Holstein steers. However, filtration method had no significant influence on degradability. In addition, aflatoxin degradation did not depend upon rumen fluid collection time after feeding, as no significant differences were observed. Finally, a comparison of two types of diet high in roughage found aflatoxin degradability in goats was higher with timothy hay opposed to rice straw, although individual variation existed. Thus, our findings showed the aflatoxin degradability is comparatively higher in goats compared to steers.     

ELISA检测饲料中莱克多巴胺的不确定度分析

为探讨酶联免疫吸附法(ELISA)检测结果的影响因素,试验分析了ELISA法检测饲料中莱克多巴胺的不确定度。依据JJF 1059-1999《测量不确定度评定与表示》和CNAS-GL06《化学分析中不确定度的评估指南》规定的测量不确定度的基本方法,分析不确定度来源并进行量化,找出主要影响因素。结果显示,ELISA法检测饲料中莱克多巴胺含量为43.75 ng/kg时,其扩展不确定度为6.77 ng/kg,k=2。影响不确定度的主要因素为样品称量、测量重复性和标准曲线拟合。     

酶联免疫法对生鲜乳中黄曲霉毒素M1的快速检测

采用酶联免疫法（ELISA）对生鲜乳中黄曲霉毒素M₁进行检测,对比了3个不同厂家的试剂盒检测结果。结果表明,在空白样品中添加浓度为0.5、1.0、2.5 μg/kg时,试剂盒的回收率在93.5%～103.5%。不同厂家的试剂盒测定结果重复性、精确度均较好,说明酶联免疫法能够有效检测生鲜乳中黄曲霉毒素M₁。     

硒对黄曲霉毒素B1中毒雏鸭血清抗氧化功能的影响

为观察黄曲霉毒素B1(aflatoxin B1,AFB1)对试验雏鸭血清抗氧化功能的影响及亚硒酸钠对AFB1的颉颃效应,选用7日龄雏鸭90只,随机分为3组,每组30只.Ⅰ组为空白对照组,灌胃同等量二甲基亚砜;Ⅱ、Ⅲ组为试验组.Ⅱ组、Ⅲ组每天按0.1 mg/kg体重剂量灌胃AFB1,同时给Ⅲ组每天按l mg/kg剂量灌胃...     

Effect of experimental feed additives on aflatoxin in milk of dairy cows fed aflatoxin‐contaminated diets

Three studies were conducted to determine the potential of experimental feed additives (EFAs), clays or non‐digestible yeast oligosaccharides, to reduce milk aflatoxin (AFM₁) concentrations in lactating Holstein cows consuming aflatoxin‐contaminated diets. All studies included a pre‐treatment period and a 2‐week experimental period in a randomized block design. During the pre‐treatment period, cows received a total mixed ration (TMR) with no aflatoxin contamination. During both experimental weeks, all cows were fed a TMR containing aflatoxin‐contaminated corn. During experimental week 1, cows received no EFA’s in the TMR, but EFA’s were included in the TMR for the second experimental week. In studies 1 and 2, the experimental period consisted of 2 weeks each lasting 7 days with 12 cows per treatment. Aflatoxin M₁ concentrations were analysed by HPLC for milk samples collected on days 5–7 and days 11–14. In various experiments, treatments included control (no EFA), 100 g/cow daily of experimental Lallemand^® product, 10 g/cow daily of MTB‐100^®‐2004, (Alltech, Inc.), 10 g/cow daily of MTB‐100^®‐2006, (Alltech, Inc.), 10 g/cow daily of experimental Alltech^® product (Alltech, Inc.) and 227 g/cow daily of Astra‐Ben 20^® (AB‐20^®; Prince Agri Products, Inc.). In study 3, the experimental period of 2 weeks each lasting 8 days and milk samples were collected from day 4 to 8 and day 11 to 16. Milk samples from study 3 were analysed for AFM₁ concentrations by ELISA. For all experiments, changes in AFM₁ concentrations because of the addition of EFA’s were calculated. Four of the five EFAs tested in this study had no significant effect on AFM₁ concentrations. However, the addition of AB‐20^® resulted in a significant decrease in AFM₁ concentrations (60.4%). In summary, the addition of AB‐20^® to the diet of cattle appears to be effective for significantly reducing AFM₁ concentrations in the milk of cows fed an aflatoxin‐contaminated diet.     

A novel mycotoxin purification system using magnetic nanoparticles for the recovery of aflatoxin B1 and zearalenone from feed

In this study, we developed a novel tool for purifying two mycotoxins, aflatoxin B1 (AFB1) and zearalenone (ZEN), in feed. This system utilized monoclonal antibodies (mAbs) against AFB1 and ZEN, and magnetic nanoparticles (MNPs). Among ten MNPs with different diameters and functional groups, a 100-nm diameter MNP (fMA) conjugated to an amine group (-NH₂) was found to be optimum for coupling with mAbs. The optimal mAb concentrations for coupling to the fMA along with mycotoxin purification capacities of the fMA-mAb conjugates (fMA-AFB1 and fMA-ZEN) were determined. A comparison of mean recovery rates (from corn and product X feed) between the fMA-mAb conjugates and immunoaffinity columns (IAC-AFB1 and IAC-ZEN) showed that the rate for fMA-AFB1 (90~92% and 81~88%) was higher (p > 0.05) than that of IAC-AFB1 (81~84% and 72~78%) for AFB1 (5, 10, 15 ng/mL), and the rate for fMA-ZEN (99~100% and 92~94%) was significantly higher (p < 0.01) than that of IAC-ZEN (86~88% and 81~88%) for ZEN (10, 25, 50 ng/mL) except at a concentration of 10 ng/mL, demonstrating the remarkable purification efficiency of the novel fMA-mAb method. Additionally, mycotoxin purification was much faster using our novel method (approx. 5 min) than the IAC-based technique (> 30 min). This study suggests that the novel purification system we developed would be a useful tool for monitoring and regulating mycotoxin contamination in feed, and replace IAC methods.