酶联免疫吸附法检测动物源性食品中恩诺沙星残留量

为检测动物源性食品中恩诺沙星残留量,评估基于卵黄抗体的间接竞争酶联免疫吸附法检测恩诺沙星的可行性,用活性脂法将恩诺沙星同卵清蛋白偶联制备免疫原和包被抗原并用紫外光谱进行验证。用聚乙二醇-6000提取卵黄抗体。五免之后效价达到峰值1∶32 000。用间接竞争酶联免疫吸附法确定包被原质量浓度、卵黄抗体的稀释倍数和IC_(50)分别为38 ng/m L、1∶64 000和18.207 ng/m L,回归曲线方程为y=0.891 1-0.016 5x(R~2=0.990)。结果表明,制备的抗恩诺沙星卵黄抗体为进一步建立检测动物源性食品中恩诺沙星的残留的免疫方法提供参考依据。     

蛋白芯片法快速测定食品中氯霉素和磺胺二甲嘧啶残留

人们对食品中药物残留检测方法提出了快速检测、准确定量的要求。本文研究了蛋白芯片法快速定量检测食品中氯霉素和磺胺二甲嘧啶残留。芯片上固定氯霉素和磺胺二甲嘧啶人工抗原,芯片反应区内加入氯霉素和磺胺二甲嘧啶单克隆抗体和其标准品或待测样品混合物,待抗原抗体完全反应后加入荧光标记二抗示踪。不同浓度的竞争标准品与检测荧光强度作标准曲线,然后通过标准曲线对待检试样中氯霉素和磺胺二甲嘧啶残留量进行定量分析,并同现行的免疫学测定方法进行了比较。     

动物源性食品中磺胺类药物的多残留酶联免疫测定方法研究进展

综述了动物源性食品中磺胺类药物多残留检测的酶联免疫测定方法研究进展.分别对磺胺药物特异性抗体制备的基本原理,栽体与半抗原的连接方法,异源系统在磺胺药物多残留检测中的应用现状进行了详细阐述.     

酶联免疫吸附法检测动物源性食品中氨苯砜残留

应用间接竞争酶联免疫吸附技术,建立了一种快速检测动物源性食品中氨苯砜残留的方法,并对其各项技术参数进行了评价。结果显示,该方法的半数抑制浓度IC50为0.369μg/L,对鸡肉、猪肉样本的检测限为0.2μg/kg,对鸡蛋、蜂蜜样本的检测限为2μg/kg,对牛奶样本的检测限为0.6μg/L;样本添加回收率为78.2%~104.0%,变异系数为5.2%~13.5%;对实际样本的检测结果与液相色谱-串联质谱法基本一致。该方法操灵敏度高、快速准确,适用于动物源性食品中氨苯砜残留的快速检测。     

SM_2单克隆抗体的初步应用研究

以磺胺二甲嘧啶(SM2)-人血清白蛋白(HSA)为免疫抗原和SM2-卵清白蛋白(OVA)为包被抗原。制备SM2单克隆抗体;利用杂交瘤技术和有限稀释法经亚克隆,得到三株特异性稳定分泌SM2抗体的杂交瘤细胞,与其他四种磺胺药和两种载体蛋白HSA、OVA均无交叉反应。利用本试验制备的单克隆抗体初步建立了动物组织中检测SM2的间接竞争ELISA方法。最低检出限为9.95 ng/mL,灵敏度为47.12 ng/mL。     

苄嘧磺隆人工抗原的合成与鉴定

以2-甲酸甲酯苄磺酰胺和琥珀酸酐为原料合成半抗原(hapten),经薄层层析和1H-NMR鉴定后,采用混合酸酐法分别与牛血清蛋白(BSA)和卵清白蛋白(OVA)偶联获得免疫原(hapten-BSA)和包被原(hapten-OVA),紫外光谱分析法计算得其偶联比分别为8:1和13:1,初步说明具有较好免疫原性。通过动物免疫实验获得了效价达1:32000的阳性血清,采用间接酶联免疫吸附检测(ELISA)法检测抗体的IC50和IC10值为0.5032mg/L和0.0024mg/L,表明人工抗原合成成功。     

磺胺二甲嘧啶间接竞争化学发光酶免疫分析法的建立及应用

建立一种更加灵敏的磺胺二甲嘧啶(SM₂)免疫学检测方法。方法 本研究制备抗SM₂单克隆抗体(SM₂-mAb),用于建立SM₂间接竞争化学发光酶免疫分析法(SM₂-CLEIA),并检测主要动物食品中SM₂残留。结果 本研究制备的SM₂-mAb为IgG_2b亚类,亲和常数为0.12×10⁷ L/mol;SM₂-CLEIA曲线在0.1～1 000 μg/L之间呈现良好的线性关系,相关系数r²=0.990 4,半数抑制浓度(IC₅₀)为4.006 μg/L,检测限为0.174 μg/L,添加回收率为94.41%～104.40%,批内和批间变异系数分别为3.07%和8.22%,与磺胺脒等药物无交叉反应,与SM₂-ELISA试剂盒的阴阳性符合率为100%。结论 建立了灵敏、特异、准确、检测范围宽的SM₂-CLEIA检测方法。     

畜产品中磺胺药物残留的检测研究

建立了检测畜产品中磺胺二甲嘧啶 SM2 的间接竞争酶联免疫反应吸附法 (EL ISA)。以 SM2 、丁二酸酐 (SA)再加上牛血清白蛋白 (BSA)或卵白蛋白 (OA)的结合物免疫小鼠 ,制备特异性针对 SM2 的多克隆抗体。畜产品试样经提取后用 ELISA检测。测定浓度范围 2 .0～ 1 2 0 ng/ ml,最小检测限 2 .0 ng/ ml。      

畜产品中磺胺药物残留的检测研究

建立了检测畜产品中磺胺二甲嘧啶 SM2 的间接竞争酶联免疫反应吸附法 (EL ISA)。以 SM2 、丁二酸酐 (SA)再加上牛血清白蛋白 (BSA)或卵白蛋白 (OA)的结合物免疫小鼠 ,制备特异性针对 SM2 的多克隆抗体。畜产品试样经提取后用 ELISA检测。测定浓度范围 2 .0～ 1 2 0 ng/ ml,最小检测限 2 .0 ng/ ml。     

QuEChERS在动物源性食品兽药残留检测中的研究进展

QuEChERS是基于分散固相萃取建立起来的一种农药多残留快速(quick)、简单(easy)、便宜(cheap)、高效(effective)、耐用(rugged)和安全(safe)的分析方法。其基本流程为采用乙腈或含体积分数1%乙酸的乙腈提取,加入无水硫酸镁和氯化钠吸水并促使提取液分层,上清液加入硅胶基伯胺仲胺键合相吸附剂(PSA)、C18或石墨化炭黑(GCB)等吸附剂除去基质干扰物,最后用气-质联用(GC-MS)或液-质联用(LC-MS/MS)分析测定。在兽药残留分析中,QuEChERS主要用于牛奶、动物源性食品肌肉或肝脏组织中磺胺类、喹诺酮类、苯并咪唑类等兽药的分析。本文对QuEChERS在兽药残留领域的应用进展做一综述,以期为兽药残留分析方法及思路提供一定的参考。     

QuEChERS法在食品有机污染物检测中的研究进展

食品中的农药残留、真菌毒素、兽药残留等有机污染物是危害食品安全的主要因素之一,因此,建立食品中多种有机污染物的高效提取和净化方法对于快速了解食品中有机污染物含量、保障食品安全具有十分重要的意义。本文在介绍QuEChERS(quick,easy,cheap,effective,rugged and safe)法及其近年来在食品有机污染物检测中的应用基础上,对其在应用过程中存在的问题进行了系统分析,提出该方法优化的一般思路,并展望了该方法在食品有机污染物检测中的未来发展趋势。     

Determination of tetracycline residues in chicken meat by liquid chromatography-tandem mass spectrometry

Analysis of residual levels of tetracyclines (TCs) in chicken meat was performed using a validated liquid chromatography coupled with a tandem mass spectrometry (LC-MS/MS) technique. Overall, the recoveries for TCs ranged from 56.9% to 101.2%, with standard deviations of 4.5–13.2%. Detection limits ranged from 7.9 to 14.6?µg?kg^?1. In four of 60 samples, doxycycline (DXC) was determined in a range from 19.9 to 35.6?µg?kg^?1; and in one sample tetracycline was detected at 17.2?µg?kg^?1. Chlortetracycline (CTC) and oxytetracycline (OTC) were not detected in any of the tested samples. This study indicates that chicken meat sold in Bursa, Turkey, contained some residues of TCs. Therefore, stricter regulations for the use of antibiotics in the poultry industry and the monitoring of drug residues in chicken meat prior to marketing are needed. Finally, this method has been applied successfully for the confirmation of TCs in chicken meat.     

Residue control of coccidiostats in food of animal origin in Poland during 2007–2010

Coccidiostats are widely used as feed additives to prevent coccidiosis. The off-label use of anticoccidials or feeding non-target animals with cross-contaminated feedingstuffs may result in the occurrence of coccidiostat residues in animal tissues and eggs. In EU countries, food of animal origin is subjected to official control of residues according to Council Directive 96/23/EC. In Poland, within the framework of the National Residue Control Plan, 3718 samples (3533 targeted and 185 suspect) of animal liver, eggs, drinking water and feed were tested for coccidiostats between 2007 and 2010. Violative residues of nicarbazin, lasalocid, maduramicin, salinomycin, semduramicin and robenidine were detected in 77 food samples (53 samples of chicken liver, 23 samples of eggs and 1 sample of turkey liver). A high percentage (31%) of non-compliant feed samples collected during follow-up investigations was observed, which confirms that feed cross-contamination may be the reason of the occurrence of coccidiostat residues in food.     

食品中残留19-去甲睾酮免疫原的合成与鉴定

19-去甲睾酮(19-nortestosteroneNT),属于半抗原生物小分子,具有免疫反应性,但不具有免疫原性。本文中19-去甲睾酮经羧甲基羟胺肟化,质谱(MS)检验后,采用混合酸酐法将肟化产物与牛血清蛋白(bovineserumalbuminBSA)偶联,紫外分光光度法测定其交联率为24。用此合成产物进行动物体免疫,获得了NT的多克隆抗体。经间接酶联免疫测定,其抗血清的稀释度可以达到1:102400,证明诺龙免疫原的合成成功,为诺龙酶联免疫试剂盒的研究奠定基础。     

食品中农兽药残留检测新技术研究进展

农兽药残留是造成食品安全问题的一个重要方面,已经引起了社会的广泛关注。针对食品中农兽药残留开发检测的新技术、新方法及相关应用研究工作近几年来取得了较大进展。本文对农兽药残留检测常用方法和技术及近年相关研究进展作了详细的综述,并对其未来的发展方向做了展望,以期为相关检测技术的进一步发展提供参考与借鉴。     

Survey of 11 nitroimidazole residues in hen and duck eggs from the Irish market

A liquid chromatography–tandem mass spectrometry method, recently developed, validated and accredited, was used to screen for metronidazole, ronidazole dimetridazole ipronidazole, ternidazole, tinidazole, ornidazole carnidazole and three hydroxy metabolites (hydroxy-metronidazole, HMMNI and hydroxy-ipronidazole) in Irish retail egg samples. The method used had decision limits (CCα) in the range 0.33–1.26?µg?kg^?1 and detection capabilities (CCβ) ranging 0.56–2.15?µg?kg^?1 for all analytes. Internal standard-corrected recovery, calculated for the various analytes, ranged 87.2–106.2%, while the coefficient of variance, expressed as % CV, ranged 3.7–11.3%. The method was applied to 160 samples of caged, free range and organic hen and duck eggs available on the Irish retail market as well as two incurred proficiency test egg samples. No nitroimidazole residues were detected in the survey samples above the CCα and the results achieved for the two proficiency test samples were acceptable when compared with the assigned values.     

胶体金标免疫固相膜检测动物性食品中氟甲喹

氟甲喹(flumequine,FLU)是动物专用的抗生素,滥用或超标使用会造成动物性食品中的残留问题,对人类健康造成危害。以活泼酯法制备氟甲喹完全抗原,免疫新西兰大耳白兔获得抗血清,通过间接竞争酶联免疫法(enzyme linked immunosorbent assay,ELISA)测定抗血清的效价和亲和性,效价为1∶12 800,纯化后抗体的IC50达到0.055 ng/mL。采用柠檬酸三钠还原法制备胶体金,并用于标记FLU多克隆抗体制备免疫金。以硝酸纤维素膜为固相载体,包被上包被原和酶标二抗作为检测线和控制线,优化检测条件:封闭液为5%脱脂乳、酶标二抗稀释40倍、包被量1.0μg、免疫金稀释度1∶5(体积比)、金标抗体与待测溶液混合比例1∶5(体积比)。在最优条件下,制成FLU胶体金标记免疫固相膜,最低检出限达40μg/L。建立的胶体金标记固相膜免疫检测方法适于大量样品的快速定性筛查。     

Detection of 3-amino-2-oxazolidinone (AOZ), a tissue-bound metabolite of the nitrofuran furazolidone, in prawn tissue by enzyme immunoassay

Furazolidone, a nitrofuran antibiotic, is banned from use in food animal production within the European Union. Increasingly, compliance with this ban is monitored by use of analytical methods to detect a stable tissue-bound metabolite, 3-amino-2-oxazolidinone (AOZ). Widespread use of furazolidone in poultry and prawns imported into Europe highlighted the urgent need for development of nitrofuran immunoassay screening tests. The first enzyme-linked immunoabsorbant assay for detection of AOZ residues in prawns (shrimps) is now described. Prawn samples were derivatized with o-nitrobenzaldehyde, extracted into ethyl acetate, washed with hexane and applied to a competitive enzyme immunoassay based on a rabbit polyclonal antiserum. Assay limit of detection (LOD) (mean + 3 s) calculated from the analysis of 20 known negative cold and warm water prawn samples was 0.1 µg kg^-1. Intra- and interassay relative standard deviations were determined as 18.8 and 38.2%, respectively, using a negative prawn fortified at 0.7 µg kg^-1. The detection capability (CC_β), defined as the concentration of AOZ at which 20 different fortified samples yielded results above the LOD, was achieved at fortification between 0.4 and 0.7 µg kg^-1. Incurred prawn samples (n = 8) confirmed by liquid chromatography coupled with tandem mass spectrometry detection to contain AOZ concentrations between 0.4 and 12.7 µg kg^-1 were all screened positive by this enzyme-linked immunoabsorbant assay. Further data are presented and discussed with regard to calculating assay LOD based on accepting a 5% false-positive rate with representative negative prawn samples. Such an acceptance improves the sensitivity of an ELISA and in this case permitted an LOD of 0.05 µg kg^-1 and a CC_β of below 0.4 µg kg^-1.     

Development of an enhanced histopathological approach to detect low-dose dexamethasone illicit treatment in veal calves

Dexamethasone is one of a number of synthetic corticosteroids illegally used to promote growth in food-producing animals. Since these low-level drug cocktails evade detection by currently available chemical methods, simple biological indicators that can aid in laboratory analysis are needed. In an attempt to devise an accurate biological method that could detect illicit drug treatment in food-producing animals, we characterized microscopic morphologic alterations of the thymus in veal calves administered low-dose dexamethasone versus control animals. For this purpose, 122 male calves were farmed for 6 months in controlled condition: 81 animals were orally administered dexamethasone (0.4?mg?day^?1) for 20 days during the sixth month and the remaining 41 were kept as control. Urine samples were collected systematically during the treatment period, the suspension period and at the slaughterhouse. All animals were slaughtered 10 per day starting from 10 days after the last dexamethasone administration and the thymus was sampled for histological examination. The difference between the two animal groups was evaluated by means of a non-parametric test of hypothesis. No residues were detected in the urines collected since the third day after the last administration, whereas morphometric analysis of the thoracic thymus revealed a significant decrease in the cortex:medulla ratio in the treated animals (p?<?0.0005). We can conclude that this histological approach offers encouraging prospects as a screening method to overcome current limitations in controlling growth promoter abuse.