顶空气相色谱法检测羟基甲硝唑对照品中的残留溶剂

建立了羟基甲硝唑对照品中残留溶剂甲醇和丙酮的顶空气相色谱测定方法。采用Agilent-DB624石英毛细管色谱柱(30 m×0.53 mm,1.0μm);以氮气为载气,氢火焰离子化检测器为检测器,进样口温度200℃,检测器温度250℃;以起始温度30℃,保持5 min,20℃/min升温至200℃,保持2 min为程序升温方法;以顶空瓶平衡温度80℃,平衡30 min为顶空条件。结果表明,在该色谱条件下甲醇和丙酮与其他物质分离良好。甲醇在2～360μg/mL范围内线性关系良好,检测限为1.0μg/mL;丙酮在1～600μg/mL范围内线性关系良好,检测限为0.5μg/mL。甲醇回收率为98.0%～102.4%,RSD为0.6%～0.9%;丙酮回收率为97.0%～99.6%,RSD为0.6%～1.0%。本方法操作简单,准确度高,重复性好,可用于羟基甲硝唑中残留溶剂的检测。     

顶空气相色谱法测定乙酰氨基阿维菌素对照品中的残留溶剂

建立了乙酰氨基阿维菌素对照品中的残留溶剂乙醇、甲醇和丙酮的顶空气相色谱测定法。采用Agilent-HP-5毛细管色谱柱,以氮气为载气,氢火焰离子化检测器为检测器,进样口温度200℃,检测器温度为250℃,以起始温度50℃,保持10min,再以每分钟10℃的速率升温至180℃,顶空瓶平衡温度为80℃,平衡时间为30min。结果表明,在该色谱条件下乙醇、甲醇和丙酮与空白溶剂N,N-二甲基甲酰胺分离良好。乙醇在11～974μg/mL的范围内线性关系良好,检测限为5μg/mL,定量限为11μg/mL,回收率为92.1%～109.9%;甲醇在8～606μg/mL的范围内线性关系良好,检测限为4μg/mL,定量限为15μg/mL,回收率为94.4%～109.5%;丙酮在12～972μg/mL的范围内线性关系良好,检测限为2μg/mL,定量限为6μg/mL,回收率为92.5%～102.4%。该方法分离度好,回收率高,适用于乙酰氨基阿维菌素对照品中残留溶剂的检测。     

气相顶空法检测c-met抑制剂中异戊醇的残留

目的:用气相顶空外标法检测药物中的异戊醇残留。方法:将样品溶于N,N-二甲基咪唑啉酮,顶空90℃保持30 min,采用毛细管气相色谱柱HP-INNOWax(30 m×250μm×0.25μm);FID检测器;载气为氮气;流速3 mL/min;检测器温度250℃;进样口温度200℃;分流比5/1;程序升温:起始温度40℃,保持3 min,再以5℃/min温至90℃,保持5 min,最后以20℃/min升温至230℃,保持5 min。结果:异戊醇的线性范围为1.05~67.04μg/mL(R~2=0.998 2),定量限:1.05μg/mL,回收率为95.79%~98.78%,精密度1.0%,溶液稳定性符合设计要求。结论:所建立的气相顶空法灵敏准确、精密稳定,适合对药品中异戊醇的检测研究。     

顶空气相色谱法测定加米霉素原料药中有机溶剂的残留量

建立顶空气相色谱法测定加米霉素中甲醇、丙酮、异丙醇、二氯甲烷、乙酸乙酯和正庚烷共6种有机溶剂的的残留量。采用顶空气相色谱法,毛细管色谱柱为Agilent DB-624UI(30.0 m×0.32 mm,1.8μm);程序升温;FID检测器;载气为氮气;流速为3 mL·min~(-1);顶空平衡温度为90℃;平衡时间为30 min;用外标法计算甲醇、丙酮、异丙醇、二氯甲烷、乙酸乙酯和正庚烷共6种溶剂的含量。甲醇、丙酮、异丙醇、二氯甲烷、乙酸乙酯和正庚烷在各自的质量浓度范围内均具有良好的线性关系(r=0.997 3~0.999 6),平均回收率为88.1%~97.7%,检测限分别为0.60、0.10、0.20、0.28、0.10和0.000 1μg·mL~(-1)。试验结果表明本方法适用于加米霉素原料药中溶剂残留量的检查。     

阿维菌素残留溶剂气相色谱检测方法的建立

采用6%氰丙基苯基-94%二甲基聚硅氧烷为固定相的毛细管柱,进样口温度220℃,检测器温度250℃,载气:氮气,流速5 m L/min,进样量0.2μL,分流比:10∶1,程序升温:初始温度为50℃,保持5 min,以每分钟15℃的速率升温至80℃,再以每分钟26.7℃的速率升温至240℃。在该色谱条件下,甲醇与内标异丙醇及溶剂间二甲苯分离度良好,检出限为6μg/m L,重复性RSD为3.0%,添加回收率为90.8%。不同色谱柱、柱温、流速、不同进样口温度、不同检测器温度耐用性良好。结果表明该方法可用于阿维菌素残留溶剂的定量检测。     

硫酸头孢喹肟中4种有机溶剂残留量的测定

建立以气相色谱法测定硫酸头孢喹肟中乙醇、丙酮、二氯甲烷、甲苯等4种有机溶剂残留的方法。采用DB-624石英毛细管柱,FID检测器,程序升温:40℃(保持10 min)~220℃(保持5 min),升温速率为30℃.min-1,进样口温度为220℃,检测器温度为230℃,流速:5mL.min-1,分流比为20∶1。结果显示:硫酸头孢喹肟原料药中乙醇、丙酮、二氯甲烷、甲苯在所考察的浓度范围内与峰面积比值呈良好的线性关系(r=0.999 4~0.999 8),检测限分别为1.67,1.89,2.56和2.02μg.min-1(S/N=5),平均加样回收率97.69%~99.42%,RSD均小于5%(n=3)。本试验建立的色谱方法简便、灵敏、准确、重现性好,适用于硫酸头孢喹肟中有机溶剂残留量的检测。     

顶空毛细管GC法测定马波沙星原料药中6种溶剂的残留量

建立顶空毛细管气相色谱法测定马波沙星原料药中甲醇、乙醇、乙腈、二氯甲烷、苯和甲苯等6种溶剂残留量。色谱柱为DB-624毛细管柱(30m×0.53mm,3.0μm),采用程序升温的方式,检测器为火焰离子化检测器（FID）,检测器温度为250℃;顶空瓶平衡温度为105℃,平衡时间为20min。结果显示在该色谱条件下,6种溶剂均能得到良好分离; 加样回收率均在100%～110%之间(RSD＜8%,n=9),精密度重复性和稳定性结果均良好;该方法操作简便,重复性高,结果稳定可靠,可用于马波沙星残留溶剂的检测。     

HPLC-ELSD测定黄芪多糖注射液中黄芪甲苷的含量

建立了高效液相色谱一蒸发光散射法(HPLC-ELSD)测定黄芪多糖注射液中黄芪甲苷的含量。采用Agilent Ecplise XDB-C18柱(250 mm×4.6 mm,5μm);流动相,乙腈-水(35∶65);流速1.0 mL/min;柱温30℃;蒸发光散射(ELSD)检测器;漂移管温度105℃;气体流速2.70L/min,进样量20μL。结果表明:黄芪甲苷在10~400μg/mL范围内线性关系良好(R2=0.999 8),添加回收率为98.9%~99.6%,RSD为0.8%~1.8%。结果表明本法简便,快速,准确,重现性好,可用于控制该制剂的质量。     

GC法测定马香苓口服液中百秋李醇含量研究

试验旨在建立测定马香苓口服液中百秋李醇含量的研究方法。本研究采用气相色谱法,其色谱条件是使用色谱柱HP-5毛细管柱;柱温采用程序升温（初始温度150 ℃,保持18 min,以50 ℃/min速率升至280 ℃,保持5 min）;进样口温度为280 ℃;载气：高纯氮气;流速1 mL/min;进样量1 μL,分流比20：1;检测器为氢火焰离子化检测器,温度为280 ℃;氢气流速40 mL/min,空气流速370 mL/min;分别进行系统适用性试验、专属性试验、线性范围考察、检测限和定量限的确定、精密度试验、稳定性试验、重复性试验、加样回收率试验、耐用性试验,并对10批样品进行了含量测定。结果显示,专属性溶液中的溶剂峰、药液的杂质峰与主成分峰能达到有效分离且分离度符合要求（R ≥ 1.5）,表明该方法系统适用性良好;阴性对照溶液未检出色谱峰,表明样品中其他成分不干扰测定;百秋李醇定量限和检测限分别为2.842和0.812 μg/mL;百秋李醇检测质量浓度在15.86~1 015 μg/mL范围内与峰面积积分值呈良好的线性关系（y=0.869x-10.45,R²=0.999,n=7）。精密度试验、稳定性试验（日内和日间精密度）、重复性试验的平均RSD分别为0.90%、1.63%和1.83%、2.90%,其RSD均在可控范围内（RSD ≤ 3%）;平均加样回收率为95.36%,RSD=2.82%（n=6）,表明所建立的气相色谱法检测百秋李醇的含量回收率良好;进行耐用性试验,最终验证所建立的色谱方法可以稳定检测百秋李醇的含量。经方法学验证,该方法准确稳定,简便可行,能够作为马香苓口服液君药广藿香中百秋李醇的含量控制方法,同时也为该制剂质量控制提供了一种有效的检测方法,暂定本品中广藿香药材按百秋李醇计不少于47.53 μg/mL。     

禽蛋中甲硝唑残留的固相萃取-高效液相色谱-串联质谱检测方法建立

为建立优化固相萃取-高效液相色谱-串联质谱法测定禽蛋中甲硝唑残留的方法,以甲硝唑-D4为内标,将禽蛋样品（鸡蛋、鸭蛋、鹅蛋、鹌鹑蛋）用10 mL乙酸乙酯-甲醇（体积比19:1）进行提取离心,将上清液氮吹后用4 mL乙腈-水（体积比4:1）复溶,用PRiME HLB固相萃取柱净化;以Kinetex F5五氟苯基色谱柱分离,0.1%甲酸水和0.1%甲酸乙腈为流动相进行梯度洗脱,在电喷雾离子源（ESI）正离子模式下,采用多反应监测模式（MRM）进行检测,以内标法进行定量分析。结果显示：甲硝唑标准溶液在0.1~50.0 μg/L范围内呈现良好的线性关系,相关系数（R2）为0.999 81;甲硝唑在禽蛋中的检出限（LOD）和定量限（LOQ）分别为0.15 μg/kg和0.50 μg/kg,回收率为93.70%~106.83%,相对标准偏差（RSD）为1.66%~3.80%。结果表明,本研究建立的方法前处理过程简单,易于操作,结果准确,适合大批量不同种类禽蛋样品的检测,能够满足禽蛋中甲硝唑残留风险监测的需求。     

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.     

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.     

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.     

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.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -