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.     

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。     

2种大型海藻类菌孢素氨基酸提取物对纳他霉素光降解的抑制作用

纳他霉素是一种天然的食品添加剂,光照会明显影响纳他霉素活性、加速其降解.类菌孢素氨基酸(MAAs)是大型海藻中广泛存在的一类水溶性化合物,具有抗紫外辐射等多种生物活性.将红毛苔和石花菜MAAs提取物,分别加入纳他霉素溶液中,分析MAAs提取物对纳他霉素光降解的影响.在光照试验第10d,对照组纳他霉素含量为原含量的10....     

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...     

甜菜碱及其营养功能

甜菜碱是在甜菜糖蜜中发现的季铵型生物碱,是动物体代谢中间产物,具有提供甲基、调节体内渗透压、促进脂肪代谢和蛋白质合成等作用。应用于饲料中能明显改善生产效果,促进动物生长,提高抗应激能力,提高抗球虫疗效,是一种安全高效的营养性饲料添加剂。     

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。     

禽肠粉代替鱼粉饲喂肉仔鸡的试验报告

禽肠粉代替鱼粉饲喂肉仔鸡的试验报告山东省农科院畜牧兽医研究所（２５０１００）任素芳柳尧波刘玉庆武英王星凌禽肠粉是优质动物性蛋白质饲料，含有较好的可利用氨基酸与较高的代谢能，合理利用禽肠粉，有利于净化环境，降低饲料成本。本试验用最佳比例的禽肠粉代替鱼粉...     

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.     

陶瓷膜和有机膜超滤处理荔枝汁和膜垢分析及荔枝汁品质研究

应用陶瓷膜和有机膜对荔枝汁进行澄清实验,并进行采用总循环模式(TRM)研究跨膜压力(TMP)和循环流量(Qf)对膜通量(Qp)的影响,确定其各自的最优水平;采用批处理模式(TBM)研究这两个参数最优水平的组合工艺。澄清工艺中：无机陶瓷膜效果优于有机聚醚砜膜,最佳工艺条件为陶瓷膜组件、TMP 0.3MPa、Qf 40L/min。研究在TBM下,膜垢的形成原因,对微分方程--＝k(J－Jlim)J2－n进行拟合,拟合R2为无机膜0.8812和0.8478;有机膜为0.9048,并分析膜垢的形成的模式：有机膜的膜垢主要是层垢(n＝0),无机膜的膜垢形成主要是层垢和部分并在膜垢的综合情况(n＝0,n＝1)。并研究TBM模式下,总糖、总果胶、总蛋白、抗氧化活性等影响果汁品质的物质的动态过程,结果表明：在P＜0.05,无机膜在品质的保持比如总糖、抗氧化活性、总酚的截留滤等方面强于有机膜,其余的品质无显著差异。