高效液相色谱法检测鸡蛋中四环素类药物残留方法研究

试验旨在建立同时检测鸡蛋中土霉素、四环素、金霉素和多西环素4种四环素类药物残留的高效液相色谱法。将鸡蛋样品用0.1 mol/L Na₂EDTA-Mcllvaine缓冲溶液提取,通过Oasis MAX固相萃取柱净化,以乙腈—三氟乙酸(0.01 mol/mL)为流动相,梯度洗脱,反相液相色谱分离测定。结果显示,4种四环素类药物在30~1 000 ng/g范围内呈良好线性关系,检出限为10 ng/g,定量限为50 ng/g,平均回收率为67.3%~81.4%,日内相对标准偏差为2.7%~14.3%,日间相对标准偏差为0.9%~5.0%。本研究建立的高效液相色谱法可同时检测鸡蛋中的土霉素、四环素、金霉素和多西环素的药物残留,该方法灵敏度、准确度和精密度较高,操作快速、简单。     

鸡组织中磺胺对甲氧嘧啶和二甲氧苄啶残留的HPLC-MS/MS测定

建立了同时测定鸡组织中残留的磺胺对甲氧嘧啶(SMD)和二甲氧苄啶(DVD)了的高效液相色谱-串联质谱法(HPLC-MS/MS)。样品经乙腈提取,取部分提取液用正己烷脱脂后于氮气吹干,残渣用流动相溶解并定容后上机检测,外标法定量。采用C18色谱柱,流动相为乙腈和1mL/L甲酸水溶液。选择1个母离子和2个子离子进行反应监测,对磺胺对甲氧嘧啶和二甲氧苄啶残留进行定性,选择信号最强的子离子进行定量。结果显示,SMD和DVD分别在1ng/mL~200ng/mL和0.5ng/mL~100ng/mL范围内呈良好线性关系,相关系数R20.992。通过空白样品添加回收试验,所有基质中SMD和DVD的定量限分别为10μg/kg和5μg/kg,SMD和DVD分别在50、100、200μg/kg和25、50、100μg/kg 3个添加水平下的回收率为71.7%~115.0%,相对标准偏差为1.8%~13.2%,该方法定量限低,灵敏度高,重现性好,符合相关研究的要求。     

超高效液相色谱串联质谱快速检测猪肉中的沃尼妙林残留

建立了检测猪肉样品中新型兽药盐酸沃尼妙林残留的快速超高效液相色谱-串联质谱（UPLC-MS/MS）确证方法。样品使用乙腈提取,在提取过程中同时加入正己烷去除脂质杂质,离心后取乙腈提取液,浓缩至干,用1 mL 0.1%甲酸水∶乙腈（60∶40,V∶V）复溶上机。以反相C18柱作为分离柱,0.1%甲酸乙腈和0.1%甲酸水为流动相,进行梯度洗脱。方法的检测限为10μg/kg,定量限为20μg/kg;在三个浓度水平（20、50、100μg/kg）下进行添加实验,平均回收率均大于92.60%,批内相对标准偏差为1.31%~6.80%,批间相对标准偏差为3.02%~4.60%。此方法简便迅速且稳定有效,适合快速检测猪肌肉中的沃尼妙林残留。     

猪肉及猪肝中四环素类药物残留量测定的高效液相色谱法

采用高效液相色谱法建立了猪肉及猪肝中土霉素、四环素、金霉素、多西环素残留量的检测方法。试样中的四环素类药物经Na2EDTA-Mcllvaine缓冲溶液提取,硫酸和钨酸钠溶液沉淀蛋白,HLB及LCX固相萃取柱净化,高效液相色谱法测定。以0.01 mol/L三氟乙酸-乙腈为流动相,梯度洗脱,检测波长为340 nm。结果显示：四种四环素类药物在0.05~5 μg/mL质量浓度范围内呈良好的线性关系,决定系数大于0.999。本方法在猪肉中的检测限为20 μg/kg,定量限为50 μg/kg;在猪肝中的检测限为50 μg/kg,定量限为100 μg/kg。在空白猪肉组织中添加50~200 μg/kg浓度,平均回收率为62.8%~114.4%,日内相对标准偏差为0.5%~6.6%,日间相对标准偏差为21%~5.4%;在空白猪肝组织中添加100~600 μg/kg浓度,平均回收率为602%~111.9%,日内相对标准偏差为0.3%~3.1%,日间相对标准偏差为1.1%~3.5%。该方法各项技术指标均能满足残留检测要求,且重现性良好,适用于猪肉及猪肝中四环素类药物残留量的测定。     

动源性食品中常见氟喹诺酮类残留检测前处理的优化

建立了一个检测动物源性食品中6种氟喹诺酮类药物残留的高效液相色谱方法。对不同基质的样品前处理条件经行了优化：鱼、肉及肝脏样品经过乙腈-0.1 mol/L磷酸二氢钾缓冲液提取,正己烷洗涤去除油脂;蛋及乳制品样品经过乙腈提取,正己烷洗涤去除油脂。目标化合物采用高效液相色谱-荧光检测器检测,外标法定量。添加10、20、50、100μg/kg浓度水平时,回收率在82%~105%之间,相对标准偏差在4%~12%之间,方法的检出限为诺氟沙星、环丙沙星、沙拉沙星及单诺沙星为5.0μg/kg、恩诺沙星、达氟沙星为3.0μg/kg。方法操作简单、实用,基质干扰小,灵敏度高,可以满足动源性食品中氟喹诺酮类药物残留检测的需要。     

鸡蛋中阿莫西林残留HPLC-DAD检测方法的建立

为了能够准确地测定鸡蛋中阿莫西林的残留,本试验建立了高效液相色谱-二级管阵列检测器(HPLC-DAD)方法来检测鸡蛋中阿莫西林残留。采用乙腈沉淀蛋白提取鸡蛋液中的阿莫西林,以超纯水饱和的二氯甲烷作为进一步萃取纯化的溶剂,0.01 mol/L磷酸二氢钾溶液(pH=5.5)和乙腈溶液为流动相,流速为1.0 mL/min,检测波长为230 nm,样品进样量为20μL,柱温为30℃的色谱条件对鸡蛋中阿莫西林残留进行检测。结果显示,阿莫西林的质量浓度范围为0.05～100.00μg/mL,与峰面积具有良好的线性关系(R²=0.999 8);该方法的重复性、精密度和稳定性均良好,相对标准偏差在2.0%以内;平均加样回收率介于82.89%～89.92%,相对标准偏差介于1.68%～2.71%;阿莫西林检测限为0.025μg/mL,定量限为0.050μg/mL。结果表明,本试验所建立的HPLC-DAD方法操作过程简便、稳定性好、灵敏度高,可适用于鸡蛋中阿莫西林残留的准确检测。     

高效液相色谱法测定牛组织中三氯苯唑及其代谢物残留量的研究

建立了一种可同时检测牛组织中三氯苯唑及其代谢物三氯苯唑酮药物残留的高效液相色谱-紫外检测法。牛组织样品经乙腈提取,异辛烷去脂肪,PPL柱净化。以0.02 mol/L乙酸铵溶液和乙腈溶液为流动相,流速为1.0 m L/min,检测波长296 nm。结果表明,三氯苯唑、三氯苯唑酮在20~1200 ng/m L范围内,峰面积与浓度呈良好的线性关系,R2均大于0.999。方法的最低定量限为50μg/kg。三氯苯唑、三氯苯唑酮在50~600μg/kg的浓度添加水平上,其回收率在70%~100%范围内,批内、批间的相对标准偏差小于20%。     

高效液相色谱法检测鸡可食性组织中的磺胺氯吡嗪残留

对建立的一种鸡组织中磺胺氯吡嗪钠残留检测的高效液相色谱法进行复核验证。鸡组织样品中磺胺氯吡嗪钠残留经乙腈提取,正己烷去脂肪,MCX固相萃取小柱净化。采用高效液相色谱紫外检测器检测,流动相为乙腈-0.02mol/L磷酸二氢钾水溶液(35:65,V/V),紫外检测波长为272nm,外标法定量。结果显示,磺胺氯吡嗪钠标准工作液在0.04~20.0μg/mL范围内具有良好的线性关系(R^2=0.9999)。在鸡肌肉、肝脏、肾脏、皮脂各组织中添加浓度分别为40、100、200μg/kg时,各组织样品中磺胺氯吡嗪钠的回收率范围为74.70%~93.67%。磺胺氯吡嗪钠的检测限为20μg/kg,定量限为40μg/kg。复核验证的鸡组织中磺胺氯吡嗪钠残留检测高效液相色谱法可行,方法简便快捷,回收率高,适合鸡组织中磺胺氯吡嗪的残留检测。     

高效液相色谱法检测鱼肉组织中金霉素、多西环素、米诺环素的残留

建立了鱼肉组织中金霉素、多西环素、米诺环素的多残留检测的高效液相色谱法(HPLC)。样品经0.1mol/LED-TA-McIlvaine缓冲液(pH4.0)提取离心后,上清液用Oasis HLB固相萃取小柱净化,选用安捷伦Eclipse plus C18色谱柱(250mm×4.6mm,粒径5μm),以乙腈:甲醇:0.01mol/L草酸溶液(2﹕1﹕7)为流动相,流速0.5mL/min,350nm波长处测定,外标法定量。其3种药物浓度在25~200ng/mL时均与峰面积呈良好的线性关系。结果表明,3种目标物质在鱼肉组织中的检测限为25μg/kg,定量限为50μg/kg。在不同浓度添加水平下测定,平均回收率在76.5%～89.1%,批内、批间变异系数均在10.00%以内。     

UPLC-MS/MS检测牛奶中头孢哌酮代谢消除规律研究

本文建立了超高效液相色谱-串联质谱法检测牛奶中头孢哌酮的浓度,并对其在血液中残留消除进行研究。样品经过乙腈提取、氮吹、HLB柱净化后,经Acquity UPLC BEH Shield RP18(100 mm×2.1 mm,1.7μm)分离,以乙腈和0.02%甲酸水为流动相,采用多反应监测模式,方法的最低定量限低于2.0μg/L,在2.0~100μg/L浓度范围内线性良好,相关系数0.9938,通过2、20、100μg/L浓度的加标回收实验表明,回收率在75.8%~94.6%之间,RSD%在2.43%~8.95%之间,满足于牛奶中头孢哌酮类药物残留检测要求;结果表明静脉注射给药后头孢哌酮在6 h内牛奶中药物含量即可达到峰值,60 h左右牛奶中药物残留消除到低于检测限。     

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.     

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

Tropical Animal Health and Production -     

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.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

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.     

Changes in proportion of canine urinary calculi composed of calcium oxalate or struvite in specimens analyzed from 1981 through 2001

The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.     

Smart Phone Assisted City-scale Wireless Sensor Network Deployment for Transportation System Monitoring

<正>1.INTRODUCTION Ensuring transportation network security is one Of the most daunting challenges confronting homeland security agencies today.Significant research has been dedicated.To model and analyze the vulnerability of transportation systems,while notably fewer studies propose specific strategies for deploying defensive technologies to safeguard these systems.