进口动物产品中莱克多巴胺残留的快速检测

应用经验证可靠的ELISA方法,对进口猪产品进行莱克多巴胺残留快速筛选检测,对ELISA检测阳性的样品采用色谱质谱联用分析方法进行确证检测。1330份猪产品的检测结果显示,采用ELISA方法检出阳性率达11．4％（152／1330）;对ELISA阳性样品采用高效液相色谱-串联质谱（HPLC—MS／MS）或气相色谱-质谱方法（GC—MS）确证,阳性率达90．8％（138／152）。检测工作表明,综合运用快速筛选检验技术与确证检测技术可实现快速准确检测动物产品中莱克多巴胺残留,提高进出境检验工作效率。     

进口猪产品中莱克多巴胺残留的快速检测

应用经验证可靠的ELISA方法,对进口猪产品进行莱克多巴胺残留快速筛选检测,对ELISA检测阳性的样品采用色谱质谱联用分析方法进行确证检测。1330份猪产品的检测结果显示,采用ELISA方法检出阳性率达11．4％（152／1330）;对ELISA阳性样品采用高效液相色谱-串联质谱（HPLC—MS／MS）或气相色谱-质谱方法（GC—MS）确证,阳性率达90．8％（138／152）。检测工作表明,综合运用快速筛选检验技术与确证检测技术可实现快速准确检测动物产品中莱克多巴胺残留,提高进出境检验工作效率。     

猪尿液中盐酸克伦特罗残留的ELISA法和GC-MS法检测

克伦特罗(Clenbuterol，CL)，是一种人工合成的β2-肾上腺素受体激动剂。其药理作用为松弛支气管平滑肌、增加肺活量、降低气道阻力、增强支气管纤毛运动和促进痰液排出，临床上常用于防治哮喘、肺气肿等呼吸系统疾病。但当其应用剂量达治疗量的5～10倍时，CL可增强肌肉发育，降低脂肪沉积，因此又称为“瘦肉精”，常被作为饲料添加剂非法用于肉用动物的生产之中。更为重要的是，由于CL在动物体内吸收快，分布广，脂溶性高，具有残留性积累和半衰期长等药理特性。人在食用残留CL肉品后引起的中毒事件不断发生。因此，各国政府都禁止CL作为饲料添加剂用于肉用动物的生产中，我国政府也规定严禁在饲料中添加CL。同时制订了CL的最高残留限量标准。为了建立快速、敏感、特异、快速的CL免疫检测方法，本研究应用ELISA法和GC-MS法对照检测饲喂盐酸克伦特罗育肥猪的尿液样品，以确证盐酸克伦特罗快速检测ELISA试剂盒的精确性和稳定性。     

GC/MS离子法测定猪尿中瘦肉精残留的研究及应用

GC／MS离子法测定猪尿中盐酸克伦特罗的残留，具有很好的分离度，特征离子与谱库检索一致，匹配度高。浓度10-200ng／mL范围呈良好的线性关系（R=0．9947）；仪器检出限为5—10ng／mL；回收率范围为69．7％-97．6％；批内变异系数≤6．1％。批间变异系数≤3．2％。检测60批猪尿中盐酸克伦特罗的残留。检出率为0。本方法对确证猪尿中盐酸克伦特罗残留具有重要意义。     

胶体金法与ELISA法检测盐酸克伦特罗的比较试验研究

[目的]本试验通过研究胶体金法与ELISA法在检测猪尿中盐酸克伦特罗的应用，得出两种方法在目前盐酸克伦特罗快速检测中结合使用的可能，从而在保证检测灵敏度和特异性的前提下，大大提高检测速度，并以此为基础建立一个不同于以前的监管模式。[方法]采用胶体金法和酶联免疫法(ELISA)进行比较。[结果]快速检测试纸条的灵敏度为5ng／nd，共检测442份猪尿样品，ELISA阳性7份，阳性率1．6％，胶体金阳性9例，阳性率2％；假阳性率为O．5％，符合率为99．5％；并可应用在宰后猪尿、猪肝检测中。【结论】胶体金法检测盐酸克伦特罗，具有操作简便、观察直观、快速、省时，其特异性、敏感性均达到ELISA水平；可作为饲养场、生猪中转站、屠宰场、菜市场筛查盐酸克伦特罗的重要手段，具有重要意义。     

ELISA方法检测猪尿中克伦特罗的方法验证

为了验证ELISA方法检测猪尿中克伦特罗残留量的可行性,采用ELISA方法对试剂盒的校正曲线的线性相关关系、检测限、重复性和样品加标回收率进行了验证.结果为,试剂盒的校正曲线的线性相关系数为0.985;定性检出限为0.147ng/mL,定量检出限为0.490ng/mL;添加0.5ng/mL、1.0ng/mL、5.0ng/mL的克伦特罗标准液时,变异系数分别为2.29%、6.97%、2.73%,平均回收率分别为91.8%、102.4%、99.7%.结果表明应用ELISA方法检测猪尿中克伦特罗残留量符合实验室质量控制规范的要求,适合检测猪尿中克伦特罗残留量的初筛.     

同位素内标GC/MS法测定猪尿和猪肝中克伦特罗

建立了同位素内标法定量测定猪尿和猪肝中克伦特罗的方法。猪尿和猪肝用乙酸乙酯、盐酸溶液提取，再经SCX固相萃取柱净化、N，O-双三甲基硅基-三氟乙酰胺（BSTFA）衍生化，定容后用气相色谱-质谱（GC／MS）测定，并以D9一克伦特罗为内标定量。猪尿和猪肝中克伦特罗的检出限分别为0．3ng／mL和0．3ng／g，克伦特罗的测定在5．0～400ng／mL范围内具有良好的线性关系，猪尿和猪肝中的平均回收率分别为100．3％和97．2％，批内变异系数分别为2．1％～4．8％，3．4％～6．4％，批间变异系数分别为2．5％～5．1％，2．7％～6．0％。通过与外标法比较，该方法定量准确可靠，更加适宜用作猪尿和猪肝中克伦特罗的定量测定。     

气相色谱－质谱法测定猪尿中地西泮

建立了猪尿中地西泮的气相色谱-质谱（GC／MS）检测方法。样品经C18固相萃取柱净化后进行气相色谱-质谱测定。结果表明,方法定量限为0．5μg/L,线性范围为10～500μg/L。在三个添加浓度2、4、6μg/L水平上,地西泮的平均回收率为70％～120％,批内相对标准偏差〈20％、批间相对标准偏差〈12％。     

饲料中三聚氰胺ELISA检测方法的优化初探

饲料中三聚氰胺的检测方法有ELISA法、液相法、GC／MS法3种。ELISA法操作简便,检测速度快,但假阳性和假阴性高;液相法的假阳性较少．但分析速度慢．而且色谱峰的分离度受流动相的影响较为明显．导致定性与定量困难。GC／MS法的分析速度与液相法相当．其优点是准确率高,但仪器昂贵,检测成本高．过程烦琐。面对大批量样品检测．利用液相法和GC/MS法．想在短时间内得到检测结果,显然很困难。那么．能不能利用ELISA法。既能提高检测速度又能避免大量假阳性的出现呢？我们分别以BRAXIS试剂盒方法．使用其内制曲线和经确证不含三聚氰胺和三聚氰胺添加量为2mg／kg的浓缩饲料和配合饲料为阳性对照．以液相法的2mg／kg检测限为控制线,同时对100批次饲料产品进行了检测。并将筛选的三聚氰胺阳性样品进行GC,MS法确证。通过比较．探讨以类似待测样品成分、并经确证不含三聚氰胺的三聚氰胺添加样为阳性对照．以液相法的2mg／kg检测限为控制线．对样品中三聚氰胺快速测定的可行性。     

磺胺二甲基嘧啶残留快速检测试剂条的研究

磺胺类药物残留的检测通常采用酶联免疫吸附法（ELISA）、高效液相色谱法（HPLC）及气质联用法（GC—MS）等，但这些方法有操作时间长、费用高、操作技能强等缺点，不易推广。随着人们对食品安全的日益重视和食品进出口贸易的高速增长，迫切需要一种能快速检测农、兽药残留的方法。近年来，胶体金检测技术已广泛应用于小分子物质的检测，本试验采用此技术研制了一种快速检测牛奶中磺胺二甲基嘧啶残留的胶体金试剂条，具有灵敏度高、特异性强、操作简便、成本低廉等优点，市场推广应用前景广阔。     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 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 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

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%).     

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 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 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).