HPLC法同时测定磺胺二甲嘧啶含量和泰乐菌素组分

采用高效液相色谱法同时测定磺胺二甲嘧啶和泰乐菌素组分含量,采用C18(4.6×250 mm,5μm)色谱柱;以2 mol/L高氯酸钠溶液-乙腈为流动相进行梯度洗脱;流速为1.0 m L/min;检测波长为280 nm。结果表明磺胺二甲嘧啶在10~200μg/m L范围内具有良好的线性,相关系数为0.9997,检出限为0.05μg/m L,定量限为0.15μg/m L,低、中、高3个浓度加标的平均回收率为99.7%~100.1%,RSD为0.3%~0.5%,泰乐菌素D峰与A峰的分离度≥3.2;泰乐菌素C峰与磺胺二甲嘧啶分离度≥30,该方法操作简便、准确、专属性强。     

酶联免疫法检测鸡肉组织中磺胺二甲嘧啶残留量

磺胺二甲嘧啶是畜禽生产中常用的抗菌药物,但在饲料中长期添加或滥用可导致动物性食品中的药物残留,人食用含有磺胺二甲嘧啶残留的动物性食品后,会引起再生障碍性贫血,并有致癌等毒副作用。欧美各国和我国均将其列为兽药残留监控的重点。磺胺二甲嘧啶检测常用的有气相色谱一串联质谱法和高效液相色谱法等,由于对检测设备、环境条件、操作技能要求高,同时受检测周期长：小批量检测成本高等因素的限制,在基层推广应用较为困难。磺胺二甲嘧啶检测快速筛选酶联免疫法（ELLSA方法）是利用抗原与抗体的特异性免疫化学反应的基本原理进行的。样品前处理简单,检测时间短,可同时检测多个样品。     

动物性食品中磺胺二甲嘧啶残留检测方法--高效液相色谱法

农业部于 2 0 0 3年 1月 2 2日发布 2 3 6号公告 ,发布 1 2个动物性食品中兽药残留检测方法。方法之三 :动物性食品中磺胺二甲嘧啶残留检测方法—高效液相色谱法。     

饲料药物添加剂使用规范(续)

磷酸泰乐菌素、磺胺二甲嘧啶预混剂Ｔｙｌｏｓｉｎ　Ｐｈｏｓｐｈａｔｅ　ａｎｄ　Ｓｕｌｆａｍｅｔｈａｚｉｎｅ　Ｐｒｅｍｉｘ［有效成分］磷酸泰乐菌素和磺胺二甲嘧啶［含量规格］每１０００ ｇ中含泰乐菌素２２ ｇ和磺胺二甲嘧啶２２ｇ、泰乐菌素８８ ｇ和磺胺二甲嘧啶８８ ｇ或泰乐菌素１００ ｇ和磺胺二甲嘧啶１００ｇ。［适用动物］猪［作用与用途］用于预防猪痢疾，用于畜禽细菌及支原体感染。［用法与用量］混饲。每 １０００ ｋｇ饲料添加本品 ２００ ｇ（１００ ｇ泰乐菌素＋１００ｇ磺胺二甲嘧啶），连用５～７ｄ。［注意］体药…     

气相色谱-串联质谱法检测猪肉组织中的磺胺二甲嘧啶残留量

利用气相色谱-串联质谱法分析猪肉组织中的磺胺二甲嘧啶残留量。样品脱脂后,采用二氯甲烷提取样品中的目标化合物,经萃取、硅烷化衍生后,用气相色谱-串联质谱法检测,根据保留时间和质谱图谱与对照品比较进行定性与确认。所检测的磺胺二甲嘧啶的二级质谱图与标准的二级质谱图匹配良好,方法快速准确,干扰较少。该法测定磺胺二甲嘧啶的回收率为76%～110%,检出限为0.01mg/kg,适用于磺胺二甲嘧啶残留量的检测。利用气相色谱-串联质谱法分析猪肉组织中的磺胺二甲嘧啶残留量。样品脱脂后,采用二氯甲烷提取样品中的目标化合物,经萃取、硅烷化衍生后,用气相色谱-串联质谱法检测,根据保留时间和质谱图谱与对照品比较进行定性与确认。所检测的磺胺二甲嘧啶的二级质谱图与标准的二级质谱图匹配良好,方法快速准确,干扰较少。该法测定磺胺二甲嘧啶的回收率为76%～110%,检出限为0.01mg/kg,适用于磺胺二甲嘧啶残留量的检测。     

磺胺二甲嘧啶与甲氧苄啶配伍治疗仔猪白痢的疗效试验及分析

磺胺二甲嘧啶5份与甲氧苄啶1份配伍制成复方磺胺二甲嘧啶片，治疗仔猪白痢，内服，用量25mg／kg／次（按磺胺二甲嘧啶计），每日2次，有效率为92．9％。     

磺胺二甲嘧啶在麻黄鸡组织中残留消除规律研究

用添加临床剂量100 mg/kg磺胺二甲嘧啶的饲料喂养40日龄麻黄鸡,连续用药3 d,分别在停药0、12、24、48、72、96、120、144、192、240、360、480、600 h时间点对肌肉、肝和肾组织采样,检测磺胺二甲嘧啶残留浓度。停药25 d后,肌肉组织残留量为0.054 mg/kg,肝和肾组织未检出磺胺二甲嘧啶,结果表明磺胺二甲嘧啶在麻黄鸡组织中停药期为25 d,《中国兽药典》2005年版中规定磺胺二甲嘧啶10 d的停药期是不尽合理的。     

磺胺二甲嘧啶与甲氧苄啶配伍治疗仔猪白痢的疗效试验

磺胺二甲嘧啶与甲氧苄啶以5∶1配伍制成复方磺胺二甲嘧啶片,治疗仔猪白痢,内服,用量25mg/kg·次（按磺胺二甲嘧啶计）,每日2次,有效率为92.9%。     

高效液相色谱法测定鸡肉中的磺胺类药物残留

采用高效液相色谱法分离鸡肉中的磺胺嘧啶(SD)、磺胺二甲嘧啶(SM2)。磺胺甲氧嗪(SMP)、磺胺间甲氧嘧啶(SMM),磺胺甲恶唑(SMZ)、磺胺地索锌(SDM)和磺胺喹恶啉(SQ)等七种磺胺类药物残留。所用分离柱为Kromasil C18、流动相为乙腈和0．017mol／L磷酸溶液。七种磺胺类药物残留在30min内得到有效分离,峰形对称且尖锐。     

鱼肌肉中磺胺二甲嘧啶及其代谢产物的高效液相色谱法测定

研究了鲟鱼肌肉中磺胺二甲嘧啶及其主要代谢物N4 乙酰化磺胺二甲嘧啶的高效液相色谱测定法。样品用乙腈提取,正己烷脱脂,碱性氧化铝SPE柱净化,高效液相色谱 Inertsil ODS 3(4 6 mm×250 mm, 粒径 5μm),流动相:水 乙腈 乙酸(76∶24∶0 05, V/V/V)测定。在 20、100、2 000μg/kg 的添加浓度,测得 SM2、N4 ACE SM2 的平均回收率范围分别为80 4%~85.3%、88.4%~96.0%;2种药物的检测限均为10μg/kg。     

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。     

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。     

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。     

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。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。     

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.