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1.
GC-MS法同时测定生鲜乳中三聚氰胺及其类似物的研究   总被引:1,自引:0,他引:1  
采用气相色谱-质谱(GC-MS)法,建立了生鲜乳中三聚氰胺及其类似物的定性定量测定方法。试样中的三聚氰胺及其类似物经(乙腈∶水∶二乙胺=5:4:1,V/V)提取,饱和乙酸铅溶液沉淀蛋白后,氮气吹干,用BSTFA进行衍生化,气相色谱-质谱法测定。采用色谱保留时间和质谱碎片离子丰度比定性,内标法定量。采用SCAN全扫描的方式进行仪器方法学研究,每种化合物确定4个碎片离子作为监测离子,进行SIM模式定性定量分析。该方法生鲜乳中4种化合物的检出限为0.1~0.2 mg/kg;在20.0~1000μg/L的浓度范围内,线性相关系数r均大于0.999。在生鲜乳中添加0.50~50 mg/kg的三聚氰胺及其类似物,其回收率为62.0%~110.0%,相对标准偏差为2.4%~13.9%。  相似文献   

2.
采用气相色谱-质谱(GC-MS)法,建立了生鲜乳中三聚氰胺及其类似物的定性定量测定方法.试样中的三聚氰胺及其类似物经(乙腈∶水∶二乙胺=5∶4∶1,V/V)提取,饱和乙酸铅溶液沉淀蛋白后,氮气吹干,用BSTFA进行衍生化,气相色谱-质谱法测定.采用色谱保留时间和质谱碎片离子丰度比定性,内标法定量.采用SCAN全扫描的方式进行仪器方法学研究,每种化合物确定4个碎片离子作为监测离子,进行SIM模式定性定量分析.该方法生鲜乳中4种化合物的检出限为0.1~0.2 mg/kg;在20.0~ 1000 μg/L的浓度范围内,线性相关系数r均大于0.999.在生鲜乳中添加0.50 ~ 50 mg/kg的三聚氰胺及其类似物,其回收率为62.0%~110.0%,相对标准偏差为2.4% ~13.9 %.  相似文献   

3.
用于检测动物性食品中己烯雌酚残留量的常用方法有放射免疫测定(RIA)、酶免疫测定(EIA)、气相色谱(GC)、高效液相色谱(HPLC)和薄层色谱(TLC)。比较这几种方法,认为RIA法测定的灵敏度较高,测定肝脏中DES的最低检出限可达0.3μg/kg,但对放射防护的要求较高,只能在专门实验室进行。GC法需增加衍生化步骤,检出限为2~10μg/kg。HPLC法用电化学检测器的最低检出限是0.1~0.2μg/kg。TLC法用硅胶作铺板,其最低检出限是0.1μg/kg。EIA法灵敏度高、特异性强,测定中华鳖肌肉中DES的最低检出限0.02μg/kg,是目前用于检测大量样品的首选方法。  相似文献   

4.
建立了畜产品包括生鲜乳、禽蛋、禽肉中三聚氰胺残留检测的反相高效液相色谱方法。样品经1%的三氯乙酸提取,饱和乙酸铅沉淀蛋白。经固相萃取柱MCX净化,于高效液相色谱仪紫外法测定,外标法定量。三聚氰胺在0.2~20.0μg/mL范围内线性良好,相关系数为0.9998。在0.2~1.0mg/kg浓度范围内,平均加标回收率在70%以上,批内变异系数在10%以内,批间变异系数在15%以内。方法的检出限为0.05mg/kg,定量限为0.10mg/kg。该方法定量限低,回收率高,可以同时测定多种样品,方便省时,满足农产品检验工作的需要。  相似文献   

5.
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%.  相似文献   

6.
应用高效液相色谱技术,建立了育肥猪配合饲料中孟布酮的检测方法。样品经乙腈提取后,通过WAX固相萃取柱净化;采用0.5%磷酸乙腈溶液作为流动相进行梯度洗脱,经C18色谱柱分离,通过二极管阵列检测器进行测定。在0.2~10μg/mL的范围内线性关系良好,相关系数大于0.999。在0.2,0.4,2 mg/kg添加水平下,平均回收率为78.1%~90.6%,相对标准偏差均小于10%。检测限为0.06 mg/kg,定量限为0.2 mg/kg,该法准确、简单、快速。  相似文献   

7.
建立了动物血制品中三聚氰胺的HPLC测定方法。样品经1%三氯乙酸溶液、乙腈超声提取,经SPE净化后,进行高效液相色谱分析。最佳色谱条件:色谱柱ZorbaxSB-C8(4.6mm×150mm,5μm);流动相为离子对缓冲液/乙腈=95/5(V/V);流速1.0mL/min;柱温25℃;紫外检测器,检测波长235nm。三聚氰胺浓度在1.0mg/L~50mg/L范围内,线性相关系数为0.9994,最低检出浓度为0.1mg/kg,平均回收率在97.60%~100.65%之间,相对标准偏差在1.23%~3.04%之间。该方法快速简便,结果准确,重现性好。  相似文献   

8.
原料乳中三聚氰胺的高效液相色谱法测定   总被引:17,自引:0,他引:17  
原料乳中三聚氰胺经乙腈萃取后,采用Biobasic SCX色谱柱(250 nim×150mm,5μm)分离,二极管阵列紫外检测器检测.流动相为乙腈-0.05mol/L磷酸二氢钾缓冲溶液(体积比=30:70),检测波长240 nm.在添加浓度为5~20mg/kg范围内,回收率为92%~96%,相对标准偏差小于10%,方法检测限为0.25 mg/kg.  相似文献   

9.
文章建立了紫外检测器—高效液相色谱法测定生鲜乳中三聚氰胺的方法。经过阳离子交换固相萃取柱净化后的样品采用高效液相色谱法测定。采用C18色谱柱,以离子对试剂缓冲液—乙腈(85:15)为流动相,流速为1.0 m L/min,检测波长为240nm,柱温为40℃。结果表明,三聚氰胺在1.0~100μg/m L的浓度范围呈良好的线性关系。三聚氰胺的标准曲线为y=82422x+64465,相关系数r为0.9997,回收率在91.7%~103.4%之间,方法检出限为0.3mg/kg,方法的定量限约为1.0 mg/kg。该方法具有操作简单,灵敏高,重复性好,回收率高等优点,可用于生鲜乳中三聚氰胺的分析测定。  相似文献   

10.
建立高效液相色谱法测定牛乳中灭蝇胺及其代谢产物三聚氰胺含量的分析方法。采用外标法对线性关系、精密度、回收率、检出限以及定量限等指标定量。结果表明,该方法在0.0~1.0 mg/L线性良好(R2>0.999),灭蝇胺、三聚氰胺检出限分别为0.003、0.004 mg/kg,定量限分别为0.008、0.010 mg/kg,平均加标回收率分别为84.4%~89.5%、83.9%~91.2%,相对标准偏差均小于10%。该研究方法具有灵敏、准确、重现性好等特点,能满足牛乳中灭蝇胺及其代谢产物三聚氰胺的测定需求。  相似文献   

11.
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。  相似文献   

12.
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.  相似文献   

13.
14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
<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.  相似文献   

20.
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.  相似文献   

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