LC-MS／MS法测定饲料中盐酸克伦特罗不确定度的研究

通过对饲料中盐酸克伦特罗测定过程中样品的称重、提取、标准溶液的配制、内标的配制和添加、标准曲线的建立等因素进行分析研究，并建立了数学模型。结果表明：标准溶液和内标的配制、样品的处理、标准曲线等对检测的不确定度贡献最大，而电子天平称重影响较小。分析得出被测量（饲料中盐酸克伦特罗）的合成标准不确定度u（cx）=0．229mg／kg，取包含因子k=2，则扩展不确定度分别为0．459mg／kg，测量结果的表述为（130．07＋0．459）mg／kg，真实的反映了测量的置信度和准确度。     

盐酸异丙肾上腺素致犬慢性心肌缺血模型的制备

为制备盐酸异丙肾上腺素致犬慢性心肌缺血模型,将12只比格犬随机分为空白组及模型组,模型组犬按1.1 mg/kg剂量皮下注射盐酸异丙肾上腺素,空白组犬给予相应的生理盐水,于试验后不同时间检测血压、心率及心电图的改变。结果显示,与空白组犬相比,模型组犬血压降低(P0.01或P0.05),心率加快(P0.01或P0.05),ST段抬高(P0.01或P0.05);表明盐酸异丙肾上腺素诱导犬慢性心肌缺血模型成功建立。     

Optimization of Stachydrine Hydrochloride in Leonurus Extraction Method by HPLC-ELSD

The study was aimed to extract stachydrine hydrochloride in leonurus by HPLC-ELSD,and establish hydrochloride stachydrine determination methods for providing theoretical basis of leonurus extraction process optimization.The chromatographic conditions:venusil HILIC hydrophilic column;Mobile phase was acetonitrile -0.2% acetic acid solution (volume ratio 80:20);The flow rate was 1.0 mL/min;And the column temperature was 30 ℃;The detector was ELSD and drift tube temperature was 80 ℃ with the atomization chamber temperature 50 ℃ and carrier gas volume flow 1.0000 mL/min.The results showed that there was a good linear relationship when the stachydrine hydrochloride content was 0.49 to 4.91 μg (R²=0.9993);There was the highest rate of active ingredients extraction of when the extraction time was 1 h,material to water ratio was 20:1 and extracted for 2 times.Combined with production practice,the final optimization scheme was that the extraction time was 1.5 h,material to water ratio was 20:1 and extracted for 2 times.In summary,the determination of stachydrine hydrochloride in leonurus should use HPLC-ELSD method which had high specificity,good stability,response and reproducibility and easy to handle.This method could provide the theoretical basis for optimizing the leonurus extraction process.     

Establishment of Detection Methods for Dexamethasone Sodium Phosphate in Injections by UPLC-PDA

A detection method of dexamethasone sodium phosphate in houttuynia injection,bupleurum injection,vitamin C injection,lincomycin hydrochloride injection,and asragulus polysacharin injection was established by UPLC-PDA.The Waters ACQUITY UPLC^® BEH C18 column(2.1 mm×50 mm,1.7 μm) was used,the mobile phase consisted of 0.75% triethylamine phosphatic liquor/solution (pH 3.0)-methyl alcohol-acetonitrile(50:45:5),the flow rate was 0.3 mL/min,the column temperature had remained 25℃,photodiode array detector wavelength range was 190 to 400 nm,the recorded wavelength was 242 nm,the injection volume was 10 μL.The linear range of dexamethasone sodium phosphatel was 10.0 to 200.0 mg/L (R²=0.9999),the mean recovery and RSD for dexamethasone sodium phosphate in houttuynia injection,bupleurum injection,vitamin C injection,lincomycin hydrochloride injection and asragulus polysacharin injection were 97.54% and 1.14%,101.59% and 0.19%,100.92% and 0.92%,99.82% and 0.73%,100.08% and 0.62%,respectively.This method was accurate,easy and fast,it was suitable for detection of dexamethasone sodium phosphatein houttuynia injection and other four kinds of injections.     

UPLC-MS/MS法测定鸡肉中盐酸吗啉胍残留量

建立了测定鸡肉中盐酸吗啉胍药物残留的新型超高效液相色谱-串联质谱方法。样品用三氯乙酸-乙腈提取并去除蛋白质,然后用Waters Acquity UPLC BEH HILIC色谱柱分离,以0.1%甲酸水溶液和甲醇为流动相进行梯度洗脱,质谱采用MRM扫描,外标法定量。结果显示:吗啉胍在(1.0~60.0)ng·m L-1范围内呈良好的线性关系,相关系数(r)大于0.990;检出限为0.5 ng·m L-1,定量限为1.0 ng·m L-1。本研究前处理方法简单快捷,质谱采用MRM扫描方法,灵敏度高,能够高效、灵敏地检测鸡肉中的盐酸吗啉胍药物。     

“万乳康”与“盐酸林可霉素注射液”治疗奶牛乳房炎的效果观察

奶牛乳房炎是奶牛常见疾病,奶牛乳房炎不仅发病率高,危害大,而且防治效果不理想。致使乳房炎发病的原因是对泌乳的乳牛未能按时挤净,更易为病菌感染而发病。此外,许多乳房炎是饲喂过多的浓质饲料而发生,由于乳腺突然分泌增强,     

畜产品质量安全监管工作存在的问题与对策建议

近年来，三鹿“三聚氰胺”奶粉、双汇“瘦肉精”（盐酸克伦特罗）猪肉、违法添加“牛肉膏”等畜产品安全事件频频发生，暴露出许多畜产品安全监管工作存在的问题，引发了群众对畜禽产品的信任危机，为了更好地解决这一社会问题，保障人民群众食品安全。本文作者根据近年来的工作实践客观分析了畜产品安全监管工作存在的问题，并提出了相应的对策措施，供各级畜产品安全监管部门和广大从业人员参考。     

原子萤光光谱法在测定钼矿石砷中的应用

原子荧光光谱法(HG-AFS)测定钼矿石中的砷,钨钼铜铅锌铋镉等共存元素在不经分离或不加掩蔽剂的情况下对砷测定产生严重干扰。本文采用盐酸-硝酸(5:1)水浴加热分解样品,加入柠檬酸-碘化钾掩蔽共存元素,促进这些元素还原成低价离子或者直接形成沉淀以消除干扰;再加入硫脲-抗坏血酸还原后直接用HG-AFS测定砷。砷的检出限为0.014μg∕g,测定范围为0.2~2000μg∕g,方法精密度为0.7%~7.5%,加标回收率为92.3%~102.9%。本方法与国家标准方法相比,检出限低,检测范围宽,干扰元素不经分离可直接测定砷的含量。本文对原子荧光光谱法测定测定钼矿石中的砷的应用进行了方法总结和研究,具有较大的实用和借鉴意义。     

蚕种冷藏加工的实践与体会(下)

<正>4蚕种人工孵化技术要点为打破春制越年种进入滞育状态,以解决当年夏秋用种需要,在产卵后适当时间给予蚕种物理或化学刺激,并结合冷藏低温处理打破卵的滞育状态,恢复发育机能,直至正常孵化,这就是人工孵化。人工孵化法种类很多,目前生产上推广使用的是盐酸孵化,依处理时期不同可分为即时浸酸、冷藏浸酸、随时冷藏浸酸孵化等,前两种用得较多。4.1即时浸酸4.1.1加温即时浸酸     

科技

中国农科院发现检测反刍动物瘦肉精新技术近日,中国农业科学院北京畜牧兽医研究所张军民研究员带领科研团队,在承担行业专项＂反刍动物-受体激动剂代谢残留规律及监测关键技术研究与示范＂任务的研究中取得新展。研究结果表明用不同颜色的牛毛发作为检测靶标,能够更加准确地监测肉牛在饲养过程中是否违法使用＂瘦肉精＂,解决了目前反刍动物的监管基础数据缺乏的问题。