不同净化方式在聚醚类抗生素残留检测中应用

聚醚类抗生素主要包括莫能菌素、甲基盐霉素、拉沙洛菌素、马杜霉素、尼日利亚菌素等,是禽类抗球虫药物,也可添加在饲料中促进畜禽的生长发育和提高饲料的利用率。目前在聚醚类抗生素残留检测的净化方式中主要以固相萃取法为主,方法方便快捷,便于实验室操作使用。     

盐霉素及其对球虫病的防治效果

盐霉素是一种非常安全、有效的抗球虫剂,已成为世界养鸡生产企业使用最多的抗球虫剂。本文介绍了盐霉素的主要特点、盐霉素的物理化学性质、生物学性质、阳离子输送作用以及盐霉素的用途;比较详细地介绍了盐霉素对鸡球虫病的防治效果和国内外试验结果。     

马杜霉素渣抗球虫的效果

测定了马杜霉素渣中铅、砷、镉、铬的含量及对小白鼠的毒性和对鸡的抗球虫性能。试验结果：马杜霉素渣中铅含量１．０５ｍｇ／ｋｇ，砷含量小于１．０ｍｇ／ｋｇ，镉含量１．２ｍｇ／ｋｇ，铬含量２６ｍｇ／ｋｇ；马杜霉素渣对小白鼠的ＬＤ５０为３５４．６５ｍｇ／ｋｇ，比马杜霉素毒性大。马杜霉素渣的抗球虫指数为１７３～１７５．１，属中等强度抗球虫药。以上结果表明，马杜霉素渣可以作为抗球虫药应用，但应用时要防止中毒的发生。     

HPLC-MS/MS快速测定动物肌肉中6种聚醚类抗生素

建立动物肌肉组织中6种聚醚类抗生素(莫能菌素、马杜拉霉素、盐霉素、和拉沙洛菌素、甲基盐霉素、尼日利亚茵素)的高效液相色谱—电喷雾串联质谱快速测定法.样品经乙腈提取,并以乙腈饱和的正已烷净化,采用甲酸水溶液—甲醇体系为流动相,梯度洗脱,电喷雾离子源正离子多反应监测模式进行质谱分析.结果表明,在优化的条件下对样品进行分析检测,各抗生素的回收率为88.0％～108.7％,RSD为2.3％～6.1％(C=10μg/kg,n=5),6种待测物在1.0～150ng/mL范围内均呈线性,线性回归系数R2均大于0.99,检出限为0.05～0.2μg/kg.该方法操作简单,灵敏度高,适用于动物肌肉组织中6种聚醚类药物的批量检测分析.     

抗球虫药检测技术研究进展

球虫病是现代畜牧养殖业中常见的重要寄生虫病之一，其防治措施主要是在饲料或饮水 中加入抗球虫药物。抗球虫药可能在动物组织中残留，并通过食物链危害消费者健康，甚至危及生命。为了减少抗球虫药物残留危害，包括中国在内的世界多国均对动物源性食品中各种抗球虫药物设定了严格的最大残留限量标准。而科研工作者也建立各种抗球虫药物残留的灵敏准确检测技术方法，对动物源性食品中的抗球虫药残留情况进行有效监控。本文对目前抗球虫药的检测方法包括分光光度法，微生物法，电化学法，色谱法，免疫学法等进行了详细综述，分析了这些方法的优点及不足；并对抗球虫药物检测技术的发展前景进行了展望，为今后分析检测各类样品基质中抗球虫药物的残留提供参考和依据。     

鸡蛋中聚醚类抗生素残留检验方法研究

建立了柱后衍生高效液相色谱法同时检测鸡蛋中莫能菌素和盐霉素残留量的方法。采用ZORBAXSB-C18(4.6mm×250mm,i.d,5μm)色谱柱,选择甲醇/5%冰乙酸(体积比90∶10)为流动相,紫外检测波长为520nm。莫能菌素和盐霉素在柱后分离后与衍生试剂1(硫酸)和衍生试剂2(香草醛)在不同的反应器中先后分别发生反应。在鸡蛋中添加莫能菌素和盐霉素的量分别为0.1/0.2μg/g、0.2/0.5μg/g、0.5/1.0μg/g时,莫能菌素的回收率为84.9%～92.1%,RSD为1.56%～2.17%;盐霉素的回收率为80.8%～91.4%,RSD为1.66%～3.47%。该方法灵敏、准确,适合于鸡蛋中微量莫能菌素和盐霉素残留量的测定。     

紫外分光光度法检测海南霉素的研究（网络首发、推荐阅读）

海南霉素钠（C47H79O15Na）是一种广泛添加在鸡、牛羊等动物饲料中的新型一元酸聚醚类抗生素,主要用于防治球虫病、调节生长代谢。利用海南霉素与衍生剂发生显色反应,可以通过紫外分光光度法进行检测。结果表明,对二甲氨基苯甲醛、香草醛两种衍生剂对海南霉素衍生后衍生产物分别在595 nm、590 nm处有最大紫外吸收,海南霉素经香草醛衍生后检测限最低,当衍生剂组成为4%香草醛（g/100 mL）、20%盐酸和80%无水乙醇时,与海南霉素溶液按照4∶6（V∶V）的比例在90 ℃下衍生化反应5 min,衍生后显色效果最好,海南霉素在5~50 μg/mL浓度范围内与吸光度值呈线性关系,决定系数R2为0.993,可用于定量检测预混剂和饲料中的海南霉素含量。在饲料中定量限为4.8 mg/kg,在饲料、预混剂中海南霉素回收率分别为75%~94%、83%~101%,可作为饲料和海南霉素钠预混剂中检测海南霉素的一种有效方法。     

减少食用动物药物残留的措施

“药物残留”是肉鸡屠宰后胴体内存有的抗菌素类,球虫药类,饲料添加剂类及农药类的化学物质。为冲破贸易壁垒,农业部制定了休药期名录,要求达到进口国的标准。这是一个重要的措施。要求饲养生产单位或个人还要在饲养环境卫生、饲料、饮水、疫病防治环节做到以下     

超高效液相色谱-串联质谱法测定禽蛋类中4种四环素类抗生素残留量

目的 建立超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)测定禽蛋类中4种四环素类(tetracyclines, TCs)抗生素残留量的分析方法。方法 样品经含50 μg/mL蛋白酶K—0.1 mol/L EDTA-Na2溶液提取, Prime HLB固相萃取小柱净化, 洗脱液用氮气吹至近干, 用含甲醇和0.1%甲酸水(4+6)溶液溶解, 采用多反应监测正离子模式, 定性和定量测定禽蛋类中的四环素、土霉素、金霉素、强力霉素等4种四环素类抗生素。结果 4种四环素类抗生素在5~200 μg/L范围内呈现良好的线性关系, 相关系数均大于0.999; 方法的检出限为0.3 μg/kg, 定量限为1.0 μg/kg; 添加水平为20.0~200 μg/kg时, 平均回收率为80.5%~124%, 相对标准偏差(relative standard deviation, RSD)为0.89%~ 6.8%。结论 该方法简单、快捷, 可作为禽蛋类中四环素类抗生素的检测方法。     

豆类在猪禽饲料中的应用

豆类在猪禽饲料中的应用豆类，特别是豌豆和蚕豆，近年来日益增多地应用于猪禽饲料，并在应用中不断地获得了新的知识和经验。豆类含有一种胰蛋白酶抑制素，它有碍于蛋白质的消化。但饲用豌豆却具有很高的抗胰蛋白酶抑制素的活性。饲用豌豆还可大量用作肉用仔猪和蛋鸡的饲...     

Simultaneous analysis of coccidiostats and sulphonamides in non-target feed by HPLC-MS/MS and validation following the Commission Decision 2002/657/EC

Taking into consideration the maximum level (ML) for coccidiostats included in the European Regulation 574/2011 and the fact that the presence of residues of sulphonamides in non-target feed is forbidden, the aim of this article is to present an analytical method based on HPLC-MS/MS for the identification and quantification of sulphonamides and coccidiostats in non-target feeds. The method was validated following Commission Decision 2002/657/EC, and recovery, repeatability and reproducibility were within the limits established in the Decision. For coccidiostats, the decision limit and detection capability were calculated for the different species taking into account the ML allowed in Regulation 574/2011. The applicability of the method was investigated in 50 feed samples collected from dairy farms, 50 obtained from feed mills and 10 interlaboratory feed samples.     

Simultaneous determination of four coccidiostats in eggs and broiler meat: validation of an LC-MS/MS method.

A published confirmatory method for the quantitative determination of four ionophoric coccidiostats (lasalocid, monensin, salinomycin and narasin) in eggs and broiler meat has been further developed. It is proposed for replacement of liquid chromatography methods previously used in analysis of ionophoric coccidiostats. The samples were extracted with acetonitrile and purified on a silica solid phase extraction column. Purified samples were analysed by liquid chromatography-mass spectrometry and the method, was validated according to the Commission Decision 2002/657/EC. The validation parameters selectivity, linearity, specificity, precision, recovery, decision limit (CCalpha) and detection capability (CCbeta) were determined. The recoveries of coccidiostats analysed ranged from 64-99% in eggs and 62-100% in broiler meat. CCalpha varied from 0.8-1.4 microg/kg in eggs and from 1.5-2.5 microg/kg in broiler meat. CCbeta varied from 0.9 microg/kg to 2.0 microg/kg in eggs and from 1.7-3.2 microg/kg in broiler meat.     

Coccidiostats in milk: development of a multi-residue method and transfer of salinomycin and lasalocid from contaminated feed

A confirmatory multi-residue method was developed for the determination in milk of 19 coccidiostats (amprolium, arprinocid, clazuril, clopidol, decoquinate, diclazuril, ethopabate, halofuginone, lasalocid, maduramicin, monensin, narasin, nicarbazin, nequinate, robenidine, salinomycin, semduramicin, toltrazuril sulfone and toltrazuril sulfoxide). Sample preparation utilising extraction with organic solvent and clean up by SPE and freezing was found reliable and time-efficient. Optimised chromatography and MS conditions with positive and negative ESI achieved sufficient sensitivity and selectivity. Validation experiments has proven method usefulness for routine analysis of coccidiostats in milk samples. An on-farm study conducted on dairy cows fed with experimentally contaminated feed with salinomycin and lasalocid showed negligible transfer to milk. No residues of lasalocid were found in collected samples. Salinomycin was found only in 5 of 168 samples analysed, while the concentrations of salinomycin in those samples (0.119–0.179 µg kg^–1) was significantly below the limit of salinomycin in milk set by European Union legislation. Such low concentrations of both coccidiostats cannot be explained by conjugation during dairy cows’ metabolism, as shown by experiments with enzymatic hydrolysis.     

Use of volatile compound metabolic signatures in poultry liver to back-trace dietary exposure to rapidly metabolized xenobiotics

The study investigated the feasibility of using volatile compound signatures of liver tissues in poultry to detect previous dietary exposure to different types of xenobiotic. Six groups of broiler chickens were fed a similar diet either noncontaminated or contaminated with polychlorinated dibenzo-p-dioxins/-furans (PCDD/Fs; 3.14 pg WHO-TEQ/g feed, 12% moisture), polychlorinated biphenyls (PCBs; 0.08 pg WHO-TEQ/g feed, 12% moisture), polybrominated diphenyl ethers (PBDEs; 1.63 ng/g feed, 12% moisture), polycyclic aromatic hydrocarbons (PAHs; 0.72 μg/g fresh matter), or coccidiostats (0.5 mg/g feed, fresh matter). Each chicken liver was analyzed by solid-phase microextraction - mass spectrometry (SPME-MS) for volatile compound metabolic signature and by gas chromatography - high resolution mass spectrometry (GC-HRMS), gas chromatography - tandem mass spectrometry (GC-MS/MS), and liquid chromatography - tandem mass spectrometry (LC-MS/MS) to quantify xenobiotic residues. Volatile compound signature evidenced a liver metabolic response to PAH although these rapidly metabolized xenobiotics are undetectable in this organ by the reference methods. Similarly, the volatile compound metabolic signature enabled to differentiate the noncontaminated chickens from those contaminated with PBDEs or coccidiostats. In contrast, no clear signature was pointed out for slowly metabolized compounds such as PCDD/Fs and PCBs although their residues were found in liver at 50.93 (±6.71) and 0.67 (±0.1) pg WHO-TEQ/g fat, respectively.     

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.     

An integrated sample preparation to determine coccidiostats and emerging Fusarium-mycotoxins in various poultry tissues with LC-MS/MS

The usefulness of an existing sample preparation technique used for ionophoric coccidiostats (lasalocid, monensin, salinomycin and narasin) was applied in the analysis of emerging Fusarium-mycotoxins beauvericin (BEA) and enniatins (ENNs) in poultry tissues (liver and meat). Also, maduramicin and liver as a new sample matrix was introduced. The developed methods were validated and applied for the determination of coccidiostats and BEA/ENNs in Finnish poultry tissues in 2004-2005. The validation parameters demonstrated that the integrated sample preparation technique is applicable to the parallel determination of these contaminants in poultry tissues. Of the samples analysed (276 meat and 43 liver), only trace levels of LAS, MON, SAL, NAR and MAD were detected in 7, 3, 5, 6 and 4% of the samples, respectively. Interestingly, for the first time, traces of BEA and ENNs could also be detected in animal tissues. BEA and ENNs A, A1, B and B1 were found in 2, 0.3, 0.6, 4 and 3% of the samples, respectively. The simultaneous presence of coccidiostats and mycotoxins was detected in three turkey samples in 2004.     

Coccidiostat residues in poultry excreta

The excretion of the coccidiostats sulphaquinoxaline and decoquinate has been studied in caged broilers on diets containing 100 and 30 mg kg^?1 of the drugs respectively. Sulphaquinoxaline reached a maximum excretion of 54 mg kg^?1 (based on dried excreta) in 18 days and decoquinate a level of 37 mg kg^?1 after 14 days. When the drugs were withdrawn from the feed the excreta concentration decreased to less than 2 mg kg^?1 in 3 days. Storage of contaminated excreta at 23°C for 9 days showed contrasting effects; the sulphaquinoxaline content decreased from 56 to 35 mg kg^?1 whereas the decoquinate concentration increased from 37 to 41 mg kg^?1. Both coccidiostats appeared relatively stable when samples of excreta were dried in layers 1 cm thick in an oven at 200°C.     

Multi-residue method for detecting coccidiostats at carry-over level in feed by HPLC–MS/MS

A multi-residue HPLC–ESI–MS/MS method has been developed for the simultaneous extraction, detection and confirmation of the 11 coccidiostats referenced by Regulation 2009/8/EC (lasalocid sodium, narasin, salinomycin sodium, monensin sodium, semduramicin sodium, maduramicin ammonium alpha, robenidine hydrochloride, decoquinate, halofuginone hydrobromide, nicarbazin, and diclazuril) in feedstuffs at carry-over level. The sensitivity of the method allows quantification and confirmation for all coccidiostats below target concentration. The method was in-house validated and meets all criteria of European legislation (2002/657/EC). The precision of the method was determined under repeatability and within-laboratory reproducibility conditions; RSD_r and RSD_R were below the maximum permitted values for every tested concentration. The specificity was checked by analysing representative blank samples and blank samples fortified with potentially interfering substances (benzimidazoles, corticosteroides, triphenylmethane dyes, quinolones, nitrofurans, nitroimidazoles, phenicols); no interference were found. Concerning quantification, a quadratic regression model was fitted to every calibration curve with a regression coefficient r ² above 0.99 on each data set. Finally, the expanded uncertainty U was calculated with data obtained within the laboratory while applying the method during validation and in routine tests.     

Determination of nequinate and buquinolate in livestock products using liquid chromatography-tandem mass spectrometry

We studied the simultaneous determination of nequinate and buquinolate, which are used as feed additives to prevent coccidiosis, by means of liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The sample was extracted with acetonitrile, then loaded onto an HLB mini-column with 20% methanol. After clean-up with 20% methanol, the analytes were eluted with acetonitrile-methanol (1 : 1). The coccidiostats in the purified samples were determined using ESI-MRM mode LC-MS/MS with a sample matrix calibration curve. Mean recoveries of nequinate and buquinolate from 8 kinds of livestocks samples (chicken muscle, chicken liver, chicken heart, swine muscle, swine heart, cattle muscle, sheep muscle, egg) were in the range of 89.5% to 108.6%, and the relative standard deviation values were <20% (n=10) at the levels of 0.01 μg/g and 0.05 μg/g, respectively. The limits of quantification of these compounds were 0.001 μg/g in each sample.     

Development of a multi-class method for the identification and quantification of residues of antibiotics, coccidiostats and corticosteroids in milk by liquid chromatography-tandem mass spectrometry

Even if coccidiostats are not generally employed in dairy cows, maximum levels for these substances in milk samples have been set up in Commission Regulation 124/2009. Due to public health concerns regarding the presence of veterinary drug residues in milk, the aim of the present work is to report a multi-class high performance liquid chromatography-tandem mass spectrometry method for the simultaneous extraction, identification and quantification of seven coccidiostats, seven antimicrobial agents, three corticosteroids and an antifungal agent. Validation was conducted following the guidelines established in the European Commission Decision 2002/657/CE at the maximum concentration permitted in milk by the European Union for each drug. The method was successfully applied in 100 raw milk samples collected from ten local dairy farms and 15 milk samples bought in supermarkets. This method could be applied in routine analysis of milk samples by the dairy industry, replacing the current, non-differentiating, screening method.