超高效液相色谱-串联质谱法检测饲料中黄曲霉毒素B_1的比较研究

利用免疫亲和柱的方法对饲料中黄曲霉毒素B_1进行检测。饲料样品经70%甲醇水提取后,用水稀释,过黄曲霉毒素B_1免疫亲和柱、甲醇洗脱、去离子水稀释洗脱溶液,在超高效液相色谱串联质谱仪上进行检测。结果表明:黄曲霉毒素B_1,在2~20μg/kg上呈良好的线性关系,R~20.999;饲料黄曲霉毒素B_1添加浓度在2~20μg/kg上,回收率范围为83.50%~92.40%,RSD值小于2.0%,并用所建方法同标准NY/T 2071—2011的方法进行样品处理对比分析,从而为饲料中黄曲霉毒素B_1检测方法提供更多的选择。     

复合免疫亲和柱净化-UPLC-MS/MS测定饲料中黄曲霉毒素B1、玉米赤霉烯酮和T-2毒素

为建立饲料(浓缩饲料、配合饲料、植物性饲料原料)中黄曲霉毒素B1、玉米赤霉烯酮和T-2毒素残留量的复合免疫亲和柱净化-UPLC-MS/MS检测方法,实验样品经86％乙腈提取,复合免疫亲和柱净化,定容后经液相快速分离,电喷雾离子化,采用MRM监测模式,正负离子扫描,外标法定量.结果表明:黄曲霉毒素B1检测限为0.02μg...     

饲料中黄曲霉毒素检测及其对牛奶品质的影响

黄曲霉毒素是一种霉菌产生的毒素，易存在各类饲料和食品中。本研究采用免疫亲和柱-荧光光度法对牛奶中的黄曲霉毒素M1进行测定，而饲料中的黄曲霉毒素B1采用酶联免疫法检测，研究结果发现：本实验中的黄曲霉毒素M1的荧光光度计的最佳光谱发射波长为450 nm，分析阴性牛奶产品的黄曲霉毒素M1含量，确定数据的精确性，牛奶回收率为76.67%～93.33%，变异系数为0.45%～2.8%，满足我国制定的检测标准，该方法操作简单、快速和安全。奶牛饲料中青绿饲料、粗饲料、能量饲料和蛋白饲料样品的黄曲霉毒素B1的测定率为100%，奶牛饲料中被检测的青绿饲料、粗饲料、能量饲料和蛋白质饲料阳性样品中黄曲霉毒素B1的含量分别为11.45、4.25、5.24和7.58 μg/kg，均小于20μg/kg（国家卫生部门制定标准），属于轻度污染|不同类型牛奶样品中阳性最高值为0.201 μg/kg，阳性最低值为0.004 μg/kg，平均值最大为0.084 μg/kg，严重超过我国卫生部门制定的标准。 [关键词]饲料|黄曲霉毒素|牛奶品质     

饲料中真菌毒素含量的分析研究

为了解掌握黄曲霉毒素B1和脱氧雪腐镰刀菌烯醇（呕吐毒素）2种真菌毒素在饲料中的污染状况，对117份饲料样品进行检测。采用免疫亲和柱净化—高效液相色谱法检测，依据《饲料卫生标准》（GB13078—2017）对检测结果进行判定分析。结果表明，黄曲霉毒素B1和脱氧雪腐镰刀菌烯醇平均检出率分别为52.1%和44.4%，最大检测值分别为13.64μg/kg和2.37mg/kg。饲料样品中黄曲霉毒素B1和呕吐毒素均有检出的共24批，检出率为20.5%。从检测结果得出，黄曲霉毒素B1存在超标现象，不合格率为0.85%；在饲料样品中脱氧雪腐镰刀菌烯醇虽有检出但无超标情况。这表明霉菌毒素在饲料中的污染情况普遍存在，今后应加大对饲料中霉菌毒素的监测力度。     

酶联免疫吸附法和免疫亲和柱-高效液相色谱法在检测饲料中黄曲霉毒素B1含量中的比对研究

为了探讨酶联免疫吸附法检测饲料中黄曲霉毒素B1含量的可行性,试验采用酶联免疫吸附法(ELISA法)比对免疫亲和柱-高效液相色谱法(IAC-HPLC法),对饲料中黄曲霉毒素B1含量进行了检测,对检测结果的准确度、精密度和样品加标回收率进行了分析.ELISA法线性方程相关系数为0.9952,相对标准偏差(RSD)为1.6％...     

免疫亲和柱荧光光度法和高效液相色谱法测定饲料中黄曲霉毒素

利用免疫亲和柱荧光光度法和高效液相色谱法测定饲料中黄曲霉毒素。免疫亲和柱—荧光光度法测定饲料中的黄曲霉毒素的测定范围0～50μg/kg;线性相关系数0.99;检测灵敏度1μg/kg;变异系数<18%;回收率82%～120%;分析时间20min,不需要剧毒的黄曲霉毒素标准品。免疫亲和柱-高效液相色谱法测定可以分别定量地检测饲料中黄曲霉毒素B1,B2,G1,G2,在黄曲霉毒素B1为0～50μg/kg测定范围内其线性相关系数0.91;检测灵敏度1μg/kg;变异系数<10%;回收率81%～110%。     

免疫亲和柱荧光光度法和高效液样色谱法测定饲料中黄曲霉毒素

利用免疫亲和柱荧光光度法和高效液相色谱法测定饲料中黄曲霉毒素。免疫亲和柱一荧光光度法测定饲料中的黄曲霉毒素的测定范围10-50μg／kg；线性相关系数0．99；检测灵敏度1μg／kg；变异系数〈18％；回收率82％～120％；分析时间20min，不需要剧毒的黄曲霉毒素标准品。免疫亲和柱一高效液相色谱法测定可以分别定量地检测饲料中黄曲霉毒素B1，B2,G1，G2，在黄曲霉毒素B1为0～50μg／kg测定范围内其线性相关系数0．91；检测灵敏度1μg／kg；变异系数〈10％；回收率81％-110％。     

高效液相色谱法测定饲料中黄曲霉毒素含量的研究

旨在建立检测饲料中黄曲霉毒素B1、B2、G1、G2含量的高效液相色谱分析方法。样品用甲醇溶液提取,利用免疫亲和柱净化,以C18反相色谱柱分离,光化学衍生器衍生后应用荧光检测器检测。结果表明:4种黄曲霉毒素在0.5~20ng/mL范围内呈现良好的线性关系,回收率为71.6%~89.0%。采用该方法检测5种饲料样品中的黄曲霉毒素总量,检出率范围在74.0%~86.7%,检出值的范围为0.5~4.3μg/kg。建立的方法精密度高、重复性好,为监测饲料中黄曲霉毒素含量水平提供了有效的分析方法。     

ELISA法检测黄曲霉毒素的关键控制点

目前黄曲霉毒素检测的主要方法有：薄层法（TLC）、高效液相色谱法（HPLC）、免疫亲和柱荧光光度法、酶联免疫吸附法（ELISA）、快速荧光法。酶联免疫吸附分析法（ELISA）是测定饲料中黄曲霉毒素含量的常用方法,所涉及的仪器及试剂比较少,操作比较简单,被很多企事业单位所采用。但在应用ELISA法检测黄曲霉毒素时如果不注重操作细节问题,就可能出现假阳性,从而难以很好地监控饲料品质。     

生鲜乳中黄曲霉毒素M1检测方法研究

通过采用《GB5009.24-2016食品安全国家标准食品中黄曲霉毒素M族的测定》中高效液相色谱法来测定生鲜乳中黄曲霉毒素M1的含量,在测定过程中使用免疫亲和柱法进行精确定性、定量,然后对生鲜乳及其加标的阳性样品中的黄曲霉毒素M1含量进行测定。结果显示,待测组分的标准系列工作溶液线性关系良好(R²=0.9995),加标回收率为95.00%~105.00%,相对标准偏差为0.50%~2.00%。结果表明,本方法结果准确、重复性好,可用于生鲜乳中黄曲霉毒素M1的检测。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.     

Mechanism of Action of Probiotic Function of Lactobacilli

乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制.     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …