液相色谱-串联质谱测定猪可食性组织中8种同化激素的含量

为了建立一种同时测定猪可食性组织中睾酮、群勃龙、勃地龙、甲睾酮、炔诺酮、康力龙、丙酸睾酮、苯丙酸诺龙8种同化激素的液相色谱-串联质谱(LC-MS/MS)方法,动物样品经酶解后用乙酸乙酯提取,C18固相萃取小柱净化,采用电喷雾离子化、多反应监测方式(MRM)对8种同化激素进行测定,且8种同化激素在1~100μg/kg的系列浓度范围内均呈良好线性关系。结果表明:该方法的检测限和定量限分别为0.2~1.5μg/kg、1~2μg/kg,在3个添加水平(5,20,50μg/kg)条件下,8种同化激素的平均回收率为76.4%~103.2%,日内相对偏差(RSD)小于12%,日间RSD小于14%。应用该方法检测240份动物组织样品,其中检测出1份睾酮阳性猪肝和1份猪肉样品,浓度分别为2.92μg/kg、2.15μg/kg。     

LC-MS/MS测定猪肉中克伦特罗预处理方法的优化

为了建立一种快速、准确的检测猪肉中盐酸克伦特罗的高效液相色谱-串联质谱法(LCMS/MS法),试验采用优化的样品前处理方法,并结合LC-MS/MS法对样品进行检测。结果表明:本方法简化了前处理方法,降低了检测成本,各项指标均满足方法学要求,其中线性范围为0~10μg/L,相关系数(r)=0.999 7。信噪比(S/N)检测限为0.072μg/L,定量限为0.240μg/L,回收率为96.6%~104.0%,相对标准偏差(RSD)为1.24%。     

液相色谱-串联质谱法测定猪尿液中地西泮及其7种代谢物残留

为建立快速测定猪尿中地西泮及其7种代谢物残留的超高效液相色谱-串联质谱(UPLC-MS/MS)确证方法,本研究优化了样品净化的阳离子交换固相萃取柱(PCX柱)及其淋洗洗脱条件。猪尿液酸化后直接经PCX柱净化,依次用水、60%甲醇水溶液淋洗,最后用5%氨化甲醇洗脱;选用BEH C18色谱柱分离,UPLCMS/MS进行检测,以基质匹配标准曲线定量。结果显示:8种药物在0.3~20.0μg/L范围内具有良好的线性关系(R²≥0.995),检出限和定量限分别为0.1μg/L和0.3μg/L;各药物在3个添加浓度下回收率为73.6%~95.3%,日内、日间相对标准偏差分别为2.9%~18.6%(n=6)和2.2%~12.6%(n=3)。结果表明,本方法操作简单、快速,灵敏度高、特异性好。     

液相色谱-串联质谱法同时测定牛奶和羊奶中43种药物残留

本试验旨在建立一种液相色谱-串联质谱法(LC-MS/MS)快速测定牛奶和羊奶中β-内酰胺类、大环内酯类、磺胺类、喹诺酮类、林可胺类、四环素类、性激素类、抗虫类共8大类43种药物(47种残留标志物)的残留。样品经1%氨化乙腈提取，90%乙腈(含0.5%乙酸)重复提取，低温冷冻净化除脂，使用ACQUITY UPLC BEH C18柱(100 mm×2.1 mm, 1.7μm)色谱柱分离，以10 mmol/L甲酸铵溶液(含0.1%甲酸)和甲醇为流动相进行梯度洗脱，采用电喷雾电离(ESI)和多反应监测(MRM)模式进行检测，基质外标法进行定量。结果显示，47种残留标志物在相应线性范围内线性关系均良好，相关系数均大于0.99,方法的定量限为0.5～5μg/kg;在0.5～200μg/kg添加浓度范围内，平均回收率为61.4%～115.7%,相对标准偏差(RSD)为1.2%～11.4%。结果表明，本试验建立的方法灵敏度高、准确性好、适用性强，适用于牛奶和羊奶中43种药物的残留检测。     

超高效液相色谱—串联质谱法检测六种动物组织中盐酸氯丙嗪残留

建立了检测六种动物组织中盐酸氯丙嗪残留的超高效液相色谱-串联质谱(UPLC/MS/MS)分析方法。样品经碱性乙醚提取,浓缩后用甲醇溶解,经超高液相色谱-串联质谱在多反应检测(MRM)模式下测定。在3 min以内完成盐酸氯丙嗪的定量分析。结果显示盐酸氯丙嗪标准曲线在0.2~100μg/L浓度范围内线性良好,标准溶液中D3-氯丙嗪内标浓度为固定值5μg/L。线性相关系数(r)为0.999 8;在0.5、1、5、10μg/kg添加水平下,盐酸氯丙嗪的加标回收率在83%~104%,相对标准偏差(RSD)均小于10%(n=6);本方法对六种动物组织中盐酸氯丙嗪的定量限为0.5μg/kg(S/N10),检出限为0.2μg/kg(S/N3)。     

液相色谱-串联质谱法检测牛奶中4种阿维菌素类药物残留量的研究

建立了一种可同时检测牛奶中4种阿维菌素类药物(阿维菌素、伊维菌素、多拉菌素和埃谱利诺菌素)残留的液相色谱-串联质谱方法(LC-MS/MS)。牛奶样品经乙腈提取,高速离心去除蛋白质等杂质,C18柱净化。以0.1%甲酸水溶液和0.1%甲酸乙腈溶液为流动相进行洗脱,流速0.4 m L/min,采用基质匹配标准溶液外标法定量。结果表明:阿维菌素、伊维菌素、多拉菌素和埃谱利诺菌素在0.5~100 ng/m L浓度范围内均呈现良好的线性关系,相关系数(R2)均大于0.996;4种阿维菌素类药物的定量限均为0.5μg/kg。阿维菌素在0.5~5μg/kg添加浓度范围内,伊维菌素在0.5~20μg/kg添加浓度范围内,多拉菌素在0.5~30μg/kg添加浓度范围内,埃谱利诺菌素在0.5~40μg/kg添加浓度范围内,回收率为66.4%~120%;批内与批间相对标准偏差均小于20%。该方法具有简便快速、灵敏度高、定性准确,重复性好等特点,可以满足牛奶中4种阿维菌素类药物残留检测的要求。     

超高效液相色谱-串联质谱测定预混合饲料中11种蛋白同化激素

试验旨在建立预混合饲料中11种蛋白同化激素的超高效液相色谱-串联质谱测定方法。饲料样品经乙腈提取后,使用乙二胺-N-丙基硅烷（PSA）净化,以Phenomenex C18色谱柱（100 mm×2.1 mm,2.6μm）作为分析柱,乙腈和0.01%甲酸溶液作为流动相进行梯度洗脱。在电喷雾正电离模式下进行定性及内标法定量分析。结果显示,11种蛋白同化激素在1～100μg/L范围内线性关系良好,相关系数大于0.993 9。甲基睾酮、司坦唑醇和醋酸美伦孕酮的方法检出限为5μg/kg,定量限为10μg/kg,其余8种蛋白同化激素的方法检出限为20μg/kg,定量限为50μg/kg。11种蛋白同化激素的加标回收率为85.38%～115.72%,相对标准偏差（RSD）为0.5%～14.8%。研究表明,试验所用方法操作简单、灵敏度高且定量准确,适用于测定预混合饲料中11种蛋白同化激素含量,可为预混合饲料中的蛋白同化激素类药物非法添加监管提供一定参考。     

基于液相色谱-串联质谱法同时测定猪和鸡粪便中β-受体激动剂残留的研究

试验建立一种检测畜禽粪便中25种β-受体激动剂的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。样品经酸性乙腈提取,加C18粉净化,浓缩后用0.2%甲酸溶解进样,经液相色谱-串联质谱进行多反应检测。结果显示,在1~100μg/kg质量浓度范围内25种β-受体激动剂基质添加标准曲线线性良好。在5~50μg/kg添加水平条件下,猪和鸡粪便中25种β-受体激动剂类药物加标回收率为71.0%~103.0%,相对标准偏差(RSD)均低于15.0%;试验方法的定量限和检出限分别为5和1μg/kg。     

蜂王浆中氯霉素残留量的LC-MS/MS与ELISA检测方法研究

介绍了利用LC-MS/MS与ELISA方法快速、准确地测定蜂王浆中氯霉素残留量.前处理方法包括用酸沉淀蛋白、乙酸乙酯提取、自制硅胶柱、Oasis(HLB)小柱等净化步骤.同时,在LC-MS/MS测定方法中使用了同位素内标氯霉素-d5.建立的LC-MS/MS方法,多反应监测了氯霉素3对离子(321.0/256.9、321.0/194.0、321.0/175.8)和同位素内标氯霉素-d5 1对离子(326.0/157.1),检测低限为0.2μg/kg,线性范围为0.2～0.8μg/kg,加标回收率为97%～102%,RSD为1.9%～7.1%;ELISA方法检测低限为0.1μg/kg,该水平添加回收率为108.2%,RSD为12.2%.     

高效液相色谱-串联质谱法快速测定兽药制剂中 喹诺酮类、磺胺类等26种药物

建立了兽药制剂中喹诺酮类、磺胺类、孔雀石绿、金刚烷胺等26种药物的高效液相色谱-串联质谱法的快速筛查与定量方法。样品经0.2%甲酸乙腈超声提取，甲醇水(1∶1，V∶V)稀释10000倍后经LC-MS/MS测定。采用C18色谱柱分离，以5 mmol/L甲酸-甲酸铵与甲醇-乙腈(1∶1, V∶V)为流动相，梯度洗脱方式；质谱采用电喷雾正离子模式离子化，多反应监测模式(MRM)，外标法标准曲线定量。26种药物在0.1 ~10.0 ng/mL浓度范围内线性关系良好，相关系数r2均大于0.99。该方法检出限为0.01 mg/g，定量限为0.02 mg/g。兽药制剂中26种药物在001 mg/g~0.1 mg/g添加范围内，平均回收率为70.0%~101%，相对标准偏差(RSD) 为1.9%~8.8%。该方法简便快捷、准确度和灵敏度高，能满足兽药制剂中常规添加药物及禁用药物进行快速筛查和准确定量。     

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.