高效液相色谱-串联质谱法测定猪肉中可的松和氢化可的松残留量的不确定度评价

评定超高效液相色谱-串联质谱法测定猪肉中可的松和氢化可的松残留量的不确定度。以本单位自建方法XCZY-051《动物源食品中克仑特罗等51种兴奋剂的检测方法液相色谱-串联质谱法》为基础,结合CNAS-GL006《化学分析中的不确定度评估指南》,建立数学模型,以猪肉中检出率最高的内源性兴奋剂可的松和氢化可的松为例分析不确定度来源并计算各不确定度得到的合成标准不确定度。当样品中可的松含量为3.386 μg/kg时,其扩展不确定度为0.4374 μg/kg(k=2);当氢化可的松含量为7.866 μg/kg时,其扩展不确定度为0.9690 μg/kg(k=2)。本方法的不确定度来源主要来自样品回收率、重复性、标准溶液配制和曲线拟合。     

高效液相色谱/质谱联用仪测定盐酸克仑特罗

利用高效液相色谱质谱检测器 ,建立了检测盐酸克仑特罗的方法。其中质谱 (SIR)检出限为 0 .0 1～ 5 μg/kg ,液相色谱中外检测器的检测限为 0 .3μg/kg ,最大吸收峰 2 96nm ,符合农业部规定动物性食品中的盐酸克仑特罗检测限 :1μg/kg。本方法可用于定量、定性检测     

高效液相色谱法测定牛奶中四环素残留量的不确定度评定

建立了高效液相色谱法测定牛奶中四环素残留量的不确定度评定的数学模型.通过对测量过程中的不确定度来源进行分析与评定,当残留量为85.3 μg/kg时,求得扩展不确定度为5.0μg/kg(k=2).结果表明,标准溶液配制、重复性测量、定容体积和回收率引入的不确定度为测量结果不确定度的主要影响因素.     

高效液相色谱法测定猪肝组织中3-甲基喹喔啉-2-羧酸

本研究建立了猪肝组织中3-甲基喹喔啉-2羧酸（3-methyl-quinoxaline-2-carboxylic acid,MQCA）的高效液相色谱检测方法。采用0.3 mol/L盐酸提取猪肝组织中药物,经MAX柱净化,以乙腈∶甲醇∶0.5%甲酸水（15∶50∶35,V/V/V）为流动相,C18色谱柱进行药物分离,320 nm波长下紫外检测,结果当药物在猪肝组织中添加水平为20～250 μg/kg时,平均回收率为72.35%～85.00%,日内测定的相对标准偏差（RSD）（n＝5）为5.56%～9.49%,日间RSD(n＝3)为5.96%～9.63%。猪肝组织中MQCA的定量限为20 μg/kg,检出限为6.65 μg/kg,表明该方法灵敏度、准确度和精密度均符合兽药残留分析技术的要求,适用于猪肝组织中MQCA的检测。     

应用ELISA检测肉猪尿液中盐酸克仑特罗方法的研究

应用酶联免疫吸附法(ELISA)，检测肉猪尿液中盐酸克仑特罗残留，实现了肉猪活体盐酸克仑特罗快速测定。实验结果表明，盐酸克仑特罗的线性范围为200—2000ng/kg，最小检出限为100ng/L,样品不用前处理可直接检测，1个样品的2个平行样测定时间为45min。     

贵阳市机械化生猪屠宰厂出厂猪肉中盐酸克伦特罗残留调查

贵阳市作为贵州的政治经济文化中心,上市猪肉的质量安全不仅关系到广大市民的身心健康,还会影响全省经济发展、社会稳定与和谐。为此,本文对贵阳市辖区内的4家机械化生猪屠宰厂出厂猪肉的盐酸克仑特罗残留情况进行调查,为进一步完善贵阳市猪肉质量安全保障体系提供科学依据。主要通过采集贵阳市机械化生猪屠宰场猪肉及其对应的肝、肾样本,采用液相色谱串联质谱法测定盐酸克仑特罗含量,结果显示:采集的540份生猪肉品样本中,有33份的盐酸克伦特罗检出值为0.01~0.07μg/kg,低于国家规定标准(0.5μg/kg),未出现盐酸克仑特罗残留超标的情况。     

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。     

鸡蛋中多西环素残留测定不确定度评定

评定了高效液相色谱串联质谱法测定鸡蛋中多西环素残留量的不确定度，通过建立数学模型，对高效液相色谱^-串联质谱法测定鸡蛋中多西环素残留量进行不确定度评定，分析不确定度来源，评价其对测定结果不确定度的相对贡献，并计算合成不确定度，最终得到鸡蛋中多西环素残留量的扩展不确定度。结果显示，鸡蛋中多西环素残留量为9.18μg/kg,在95%的置信区间下，合成不确定度0.0603,扩展不确定度为0.1206(k=2),最终结果应表示为9.18±1.11μg/kg,实验过程中不确定度主要来源于工作曲线的配制过程，测量重复性和回收率。本研究可为以后的检测工作提供可行性建议。     

高效液相色谱-串联质谱法测定鸡肉中癸氧喹酯的测量不确定度评定

分析了影响应用高效液相色谱-串联质谱法测定鸡肉中癸氧喹酯残留量的测量不确定因素,并对各不确定度分量进行了量化计算,最终求得扩展不确定度为0.56μg/kg,分析表明重复测量、制备标准溶液及内标溶液引入的不确定度分量是影响癸氧喹酯残留量测量不确定度的主要因素。     

原粮中砷含量测定的不确定度评定

利用分光光度法测定原粮中的砷含量。采用原粮为材料,测定、评估原粮中砷含量测定过程中存在的各种不确定度来源及分量,并计算出其扩展不确定度。根据不确定度分量大小可以得出砷测定值的不确定度主要来源于测定过程中称量引起的不确定度。结果表明,总砷含量的扩展不确定度为0.003 3 mg/kg,砷含量检测结果为(0.510 7±0.003 3) mg/kg,在标准物质含量(0.062±0.014) mg/kg的范围内。该方法分析过程处于质控状态,结果可靠。     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.

     

Heartworm in dogs in Canada in 1986

In late December 1986, 1224 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1986; 46% of them responded. Veterinarians reported that 150,989 dogs were blood-tested for microfilariae and 869 dogs were found with heartworm. Another 65 dogs were amicrofilaremic but diagnosed with heartworm disease and one was found with heartworm at necropsy to give the total number diagnosed in 1986 as 935 (0.62%).

Heartworm was reported from Manitoba, New Brunswick, Ontario and Quebec, but most (810) of the cases were from Ontario. South-western Ontario continued to be the primary focus of the infection in Canada. There were 103 cases reported from Quebec, mostly from and around Montreal, and 21 cases from Manitoba, from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 33% of the cases were observed with clinical signs of heartworm disease and 81% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1987

In late November 1987, 1246 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1987, and 50% of them responded. Veterinarians reported that 165,428 dogs were blood tested for heartworm disease and 511 dogs were found with D. immitis microfilariae. Another 78 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1987 as 589 (0.35%).     

Scrapie in goats in Cyprus

Ovine scrapie was first recorded in Cyprus in 1985. Subsequently four dairy goats kept in two mixed flocks with affected sheep developed characteristic clinical signs similar to those seen in sheep. Fifteen goats from the two flocks were examined histologically and neurological lesions consistent with a diagnosis of scrapie were found in the four animals and in three others which had subsequently developed early neurological signs. These lesions were similar to those of naturally-affected sheep although neuronal degeneration and vacuolation were more severe in some cases.     

Heartworm in dogs in Canada in 1983

In late December 1983, 2 800 veterinarians across Canada were sent a questionnaire in order to assess the status of heartworm disease in Canada in 1983 and 26% of them responded. Veterinarians reported that 59 504 dogs were blood-tested to check for microfilariae and 771 dogs (1.30% of those tested) were found with Dirofilaria immitis. Heartworm disease was diagnosed in all provinces except New Brunswick and Newfoundland but most (733) of the cases were in Ontario.

Heartworm disease was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 31% of the cases were observed with clinical signs of heartworm disease and 64% had a history of not having left Canada. Southwestern Ontario continues to be the focus of the infection and most of the dogs there had not left the province previously.

     

Heartworm in dogs in Canada in 1991

In late November 1991, 1883 clinics in Canada were sent a questionnaire to assess the status of Dirofilaria immitis in dogs in 1991 and there was a 60.0% response. There were 344,031 dogs tested for heart-worm (HW), 627 were found infected and the prevalence of HW infection was 0.18%. There were 417 dogs with HW in Ontario, 116 in Manitoba, 38 in Quebec, 53 in British Columbia, three in Alberta, and one in Nova Scotia. In British Columbia, all of the infected dogs but one were from the Okanagan valley which, as from 1991, is a new focus of infection in Canada. Most dogs with HW had not been on preventive medication in 1990, and the prevalence among dogs tested and unprotected was 0.59%. That prevalence was considerably higher in endemic areas. Companion dogs, over three years of age and maintained primarily outdoors in rural areas, were most frequently infected. One cat was diagnosed with D. immitis and 33 dogs had Dipetalonema reconditium.     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.