超高效液相色谱-四级杆-静电场轨道阱高分辨质谱法筛查测定饲料中16种硝基咪唑类药物

建立了基于超高效液相色谱-四级杆-静电场轨道阱高分辨质谱联用(UPLC-Q-Exactive Orbitrap)快速筛查和确证定量饲料中16种硝基咪唑类药物的分析方法。饲料样品经含0.1%甲酸的乙腈-水(80:20,V/V)溶液震荡提取,Waters ACQUITY UPLC○R BEH C18色谱柱(2.1mm×100mm,1.7μm)分离,以(含0.1%甲酸)乙腈-甲醇(50:50,V/V)溶液和(含0.1%甲酸)水溶液为流动相进行梯度洗脱。静电场轨道阱全扫描得到16种硝基咪唑类药物的一级精确质量数与理论精确质量数对比,质量偏差在0.04975~0.93988mDa;同时建立了二级质谱数据库,实现对16种硝基咪唑类药物的定性筛查及同步定量。16种硝基咪唑类药物在0.1~200μg/L浓度范围内线性关系良好r>0.9990,方法检测限在25μg/Kg^100μg/Kg,回收率在49.47%~105.4%。     

亲水作用色谱-高分辨质谱测定生鲜牛乳中7种氨基糖苷类药物残留

建立了生鲜牛乳中链霉素、双氢链霉素、庆大霉素、妥布霉素、卡那霉素、阿米卡星和安普霉素共7种氨基糖苷类抗生素残留的超高效液相色谱-串联质谱检测方法。样品经100mL/L三氯乙酸-乙腈提取和WCX固相萃取柱净化后,采用亲水作用色谱分离,四极杆-静电场轨道阱高分辨质谱检测。对样品前处理条件、液相色谱流动相及质谱条件进行了优化。结果表明,7种氨基糖苷类抗生素在20μg/L~500μg/L范围内线性关系良好,生鲜牛乳中的加标回收率为88.7%~111.2%,相对标准偏差为6.3%~13.1%,该方法灵敏、准确,可用于生鲜牛乳中多种氨基糖苷类抗生素残留的同时检测。     

超高效液相色谱-二极管阵列-四极杆静电轨道阱质谱法对杆菌肽组分的分析

开发建立了超高效液相色谱-二极管阵列-串联四级杆静电场轨道阱高分辨质谱联用分析杆菌肽组分的方法。采用(Phenomenex C₁₈100 mm×3.0 mm,2.6μm)色谱柱,以0.1%甲酸溶液-0.1%甲酸甲醇乙腈(75+25)溶液为流动相,0.3 mL/min线性梯度洗脱分离,紫外吸收波长为254 nm。采集杆菌肽各组分质谱母离子及其对应子离子,并进行解析,推测组分的结构。在所建立的条件下,检测出9个组分,杆菌肽各组分之间分离良好。利用紫外与质谱归一化法测定含量,两种结果相对偏差在0.01%~3.53%之间。建立的超高效液相色谱-二极管阵列-串联四级杆静电场轨道阱高分辨质谱法能有效分析多肽类药物杆菌肽各组成成分,为杆菌肽的质量控制和工艺优化提供了参考。     

超高效液相色谱-四级杆-静电场轨道肼高分辨质谱筛查测定饲料中19种磺胺类药物

建立了超高效液相色谱-四级杆-静电场轨道阱高分辨质谱联用(UPLC-Q-Exactive Orbitrap)快速筛查和确证定量饲料中19种磺胺类药物的分析方法。饲料样品经乙腈-0.1%甲酸溶液(80:20,V/V)超声提取,Agilent SB C18色谱柱(100 mm×3.0 mm,1.8μm)分离,以0.1%(V/V)甲酸乙腈溶液和0.1%(V/V)甲酸水溶液为流动相进行梯度洗脱。静电场轨道阱全扫描得到磺胺类药物的一级精确质量数与理论精确相对分子质量对比,相对质量偏差在0.006×10-6~1.252×10-6之间,有效去除了基质干扰,实现对饲料中磺胺类药物的快速筛查;同时建立了19种磺胺类药物的二级质谱数据库,实现对19种磺胺类药物的定性筛查及同步定量。19种磺胺类药物在0.1~200μg/L浓度范围内线性关系良好r0.99,方法检测限为50μg/kg,回收率在59.61%~106.45%之间。     

液相色谱-四极杆-静电场轨道阱高分辨质谱测定鸡蛋及鸡肉中氟虫腈及其代谢物残留的研究

建立了一种测定鸡蛋与鸡肉中氟虫腈及其3种代谢物(氟甲腈、氟虫腈硫醚及氟虫腈砜)的液相色谱-四极杆-静电场轨道阱高分辨质谱方法。样品经提取和盐析后,由PRiME HLB净化柱快速净化,经液相色谱分离后,四极杆/静电场轨道阱质谱准确定性并定量,平行反应监测模式检测。4种待测组分均获得足够的色谱保留和分离,各药物在 0.1-5.0 μg/kg范围内呈现良好的线性关系,日内日间精密度小于20 %,方法回收率在75~115 %之间,方法的定量限为0.1 μg/kg。此方法快速、准确且灵敏度高,为目前国际上爆发的“毒鸡蛋”事件提供了准确有效的技术手段。     

超高效液相色谱-串联质谱法检测牛奶中7种氨基糖苷类药物残留

应用超高效液相色谱-串联质谱技术,建立了牛奶中7种氨基糖苷类药物(链霉素、双氢链霉素、庆大霉素、卡那霉素、丁胺卡那霉素、安普霉素、大观霉素)的检测方法。样品经乙酸铵缓冲液提取,固相萃取柱净化,CORTECS HILIC为分离色谱柱,采用甲酸铵溶液作为流动相进行梯度洗脱,通过多反应监测模式进行测定。在0.1~5μg/m L的范围内线性关系良好,相关系数均大于0.996。在20、50、200μg/kg添加水平下,平均回收率为80%~117.5%,相对标准偏差均小于15%。检测限为10μg/kg,定量限为20μg/kg,该方法准确、简单、快速。     

液相色谱-三重四极杆/线性离子阱复合质谱技术检测牛可食性组织中莫昔克丁的残留

建立了一种可准确定性定量检测4种牛可食性组织中莫昔克丁残留的液相色谱-三重四极杆/线性离子阱(LC-Qtrap)复合质谱分析技术.牛肌肉、肝脏、肾脏和脂肪样品经乙腈提取,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,在BEH C18色谱柱上实现分离,在电喷雾正离子(...     

超高液相色谱-静电场轨道阱高分辨质谱快速筛查与确证猪粪中二十三种喹诺酮类和四环素类药物

为了快速筛查与确证喹诺酮类及四环素类药物,及时掌握畜禽养殖过程中抗菌药物的使用情况,本研究建立了利用超高效液相色谱-四级杆-静电场轨道阱高分辨质谱快速筛查与确证猪粪中23种常见喹诺酮类及四环素类抗菌药物的方法.建立了目标药物的质谱数据库,优化了猪粪中23种常见抗菌药物喹诺酮类和四环素类药物的前处理过程.23种目标药物在...     

液相色谱-串联高分辨质谱测定鸡肉中卡巴氧、喹乙醇的代谢物残留

本研究建立了鸡肉中卡巴氧、喹乙醇的代谢物残留的液相色谱-串联高分辨质谱测定方法。鸡肉样品经酸解后,固相萃取净化,液相色谱-串联四极杆静电场轨道阱高分辨质谱测定,稳定同位素内标定量。卡巴氧、喹乙醇的代谢物喹喔啉-2-羧酸、3-甲基-喹喔啉-2-羧酸在0.5μg/kg~10 g/kg范围内线性关系良好,最低定量限0.5μg/kg,检测限0.2μg/kg。高中低浓度精密度20%(RSD%),平均回收率70%~120%。经实际样品的测定,本方法简便、实用,适宜于大批量样品的测定。     

UPLC-Q Exactive Orbitrap HRMS同时测定肉中6类28种兽药残留量

本文以QuEChERS前处理技术结合高效液相色谱-高分辨质谱技术，对肉中残留磺胺类、大环内酯、林可酰胺、酰胺醇、青霉素、β-内酰胺6类28种兽药的同时测定进行了研究。该法以0.1 mol/LNa2EDTA水溶液和乙腈为萃取溶剂，无水硫酸钠为干燥剂，吸附剂纯化浓缩，甲醇-0.1%甲酸水（1:9，V/V ） 重新溶解残渣。然后用Hypersil GOLD 25002-102130 C18柱层析分离，流动相为0.1%甲醇水溶液和甲酸溶液梯度洗脱，Q-Exactive高分辨质谱，正负离子交换采集模式电喷,外标法定量。该方法在质量浓度1 ～ 100 ng/mL内线性良好，28种兽药残留的相关系数r大于0.995。加入5、20、50 ng/kg（氯霉素、氟苯尼考1、5、20 ng/kg）测定三种不同质量浓度加标的样品，回收率为60.3% ～ 118.4%，RSD为0.23% ～ 9.73%，该方法的精密度和重复性良好。 [关键词] 肉|QuEChERS|四极杆/静电场轨道阱高分辨质谱|兽药残留     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.