液相色谱-串联质谱法同时测定生鲜乳中四环素类和β-内酰胺类药物残留

试验旨在建立了反相液相色谱-串联质谱法同时测定生鲜乳中四环素类和β-内酰胺类药物残留的方法,可用于生鲜乳中四环素、金霉素、土霉素和强力霉素等4种四环素类和阿莫西林、苄青霉素、氨苄青霉素、苯唑西林、氯唑西林、头孢氨苄、头孢噻呋等7种β-内酰胺类药物残留的同时测定。结果表明:11种化合物溶液浓度在1~80μg/L有较好的线性关系,γ>0.99,方法的检出限在0.1～1μg/L。苄青霉素的回收率较低,只有60%左右,其他化合物的回收率均在81%～119%、相对标准偏差在1.23%～14.80%。方法的灵敏度较高,且简便、快速,可以较好的解决目标物极性差别大及牛奶中蛋白质对检测结果的干扰等问题,能够很好的满足生鲜乳中抗生素残留检测的需要。     

反相高效液相色谱法对畜产品中三聚氰胺残留的检测

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。     

高效液相色谱-质谱/质谱法检测生鲜乳中孕酮残留量方法的建立和优化

为了建立生鲜乳中孕酮的高效液相色谱-质谱/质谱检测方法,试验采用生鲜乳样品经甲醇溶液提取后,用C_(18)固相萃取柱净化后,再经电喷雾离子源高效液相色谱-质谱/质谱测定,保留时间和选择离子丰度比定性,外标法定量。结果表明:孕酮在0.1~5.0 ng/mL浓度范围内呈良好线性相关,相关系数为0.999 9,建立方法的检出限为0.02μg/kg,定量限为0.04μg/kg,在0.1~5.0 ng/m L加标浓度范围内,方法的回收率为79.6%~105.1%,相对标准偏差≤8.9%。与行业标准相比,试验建立方法的检出限和定量限明显降低,增强了方法灵敏度,适用于牧场生鲜乳中孕酮残留的检测。     

生物芯片技术检测奶牛饲料中多种真菌毒素

利用生物芯片真菌毒素阵列,选用其中的赭曲霉毒素A、脱氧雪腐镰刀菌烯醇、黄曲霉毒素B1和玉米赤霉烯酮4个组分,同时测定其在奶牛饲料中的残留量,考察该生物芯片的准确性、精密度和重现性等指标。结果表明:4种真菌毒素的标准曲线线性相关系数均可达到0.99以上;试剂盒质控样品和阴性样品2个水平的加标回收率在80%～120%之间,变异系数(coefficient of variance,CV)在15%以内,方法准确性和重复性较好;对奶牛饲料样品检测结果重现性考察的CV在10%以内,表明方法重现性较好;与高效液相色谱法相比,2种检测方法的结果差异性小,且生物芯片法前处理更为简便。真菌毒素阵列生物芯片法操作简单、结果准确,缩短了大量样本的筛查时间,为批量样品筛查提供了可靠的技术保证。     

离子色谱法检测生鲜乳中硫氰酸根改进初探

本研究优化了等度离子色谱法测定生鲜乳中硫氰酸根的检测方法。样品经丙酮沉淀蛋白后,高速离心取上清液过C18柱除去样品中的脂肪,而后上机测定。结果表明,在0.1～5．0mg／L质量浓度范围内,硫氰酸根工作曲线的线性相关系数r=0．9999,加标回收率为86～94％。该方法方便可靠,可应用于生鲜乳中硫氰酸根的检测。     

固相萃取-高效液相色谱法同时检测奶牛粪污中5种磺胺类抗生素

建立的固相萃取-高效液相色谱法具有灵敏度高、检测限低的特点,可同时定量检测奶牛粪污中磺胺嘧啶、磺胺二甲嘧啶、磺胺间甲氧嘧啶、磺胺甲恶唑、磺胺喹噁啉的残留。采用C18色谱柱(500 mm×4.6 nm, 5μm),以0.3%的乙酸-乙腈溶液为流动相,在流速1.0 mL/min、检测波长270 nm、柱温30℃条件下,5种抗生素均能达到基线分离;3倍信噪比下,5种抗生素的检出限均为20μg/kg。在加标浓度50μg/kg条件下,奶牛粪污样品经前处理、MCX固相萃取小柱富集净化后,五种磺胺类抗生素回收率达到75%～80%,相对标准偏差为2.8%～3.9%。此方法检测了某规模化奶牛场粪污中磺胺类抗生素残留,结果显示,磺胺嘧啶的浓度范围在45～50μg/kg,其他抗生素无检出。     

离子色谱法测定生鲜乳中的硫氰酸根

本实验通过对离子色谱条件进行优化,建立了离子色谱法测定生鲜乳中硫氰酸根的检测方法。浓度在0.1~5.0 mg/L,硫氰酸根标准曲线的线性相关系数为0.9993,方法检出限为1.3μg/L,定量限为4.2μg/L。对样品进行加标回收实验,硫氰酸根的回收率为95%~104%,RSD为0.9%~1.5%(n=6),该方法简单可靠,重现性好,适用于生鲜乳中硫氰酸根的检测。     

酶联免疫法检测生鲜乳中三聚氰胺的研究

用酶联免疫法对25个生鲜乳样品中的三聚氰胺残留进行检测,结果显示,离散系数小于10%,平均回收率高达97.7%,且所有生鲜乳样品的三聚氰胺含量均未超标。酶联免疫法可应用于生鲜乳三聚氰胺检测的筛选试验。     

鸡组织中磺胺氯吡嗪和磺胺氯哒嗪残留的HPLC检测方法

建立了一种鸡组织样品中磺胺氯吡嗪和磺胺氯哒嗪残留量的HPLC测定方法.鸡组织样品中的药物残留经乙腈和丙酮提取,正己烷去脂肪和MCX固相萃取小柱净化.洗脱液经浓缩后,其样品中的药物残留采用HPLC紫外检测器检测,流动相为乙腈/0.017 mol/L磷酸溶液(32/68),紫外检测波长为270 nm.2种磺胺药对照品溶液在0.02～1 mg/L范围内呈良好的线性相关(r＞0.999 7).在50、100,200 μg/kg的添加水平上,磺胺氯吡嗪和磺胺氯哒嗪残在鸡组织(肌肉、肝脏和肾脏)中的回收率在70%%～85%之间,日内和日渐变异系数分别小于8%和10%.在该检测条件下,上述两种磺胺药物在鸡组织中的检出限为20μg/kg,定量限为50 μg/kg.该检测能够满足鸡组织中磺胺氯吡嗪和磺胺氯哒嗪残留的检测要求.     

生鲜乳中黄曲霉毒素M1检测方法研究

通过采用《GB5009.24-2016食品安全国家标准食品中黄曲霉毒素M族的测定》中高效液相色谱法来测定生鲜乳中黄曲霉毒素M1的含量,在测定过程中使用免疫亲和柱法进行精确定性、定量,然后对生鲜乳及其加标的阳性样品中的黄曲霉毒素M1含量进行测定。结果显示,待测组分的标准系列工作溶液线性关系良好(R²=0.9995),加标回收率为95.00%~105.00%,相对标准偏差为0.50%~2.00%。结果表明,本方法结果准确、重复性好,可用于生鲜乳中黄曲霉毒素M1的检测。     

QuEChERS-dSPE-UPLC-MS/MS筛查中药材地龙中41种兽药残留

建立了基于超高效液相色谱串联三重四极杆质谱(UPLC-MS/MS)的动态多反应监测模式(d-MRM)快速筛查中药材地龙中7大类(喹诺酮类、磺胺类、糖皮质激素类、硝基咪唑类、抗病毒类、非甾体抗炎类、镇静安眠类)41种兽药残留的分析方法。样品采用QuEChERS提取,分散式固相萃取管(dSPE EMR-Lipid)进行净化,采用d-MRM采集模式进行定性和定量检测,外标法定量,41种兽药测定在各自线性范围呈良好的线性关系,相关系数(R 2)均大于0.9917,检出限为0.1000~3.105μg/kg,定量限为0.3184~7.532μg/kg,3个添加水平的回收率为62.8%~112.3%,精密度为1.1%~8.9%。该方法前处理简单、重现性好、灵敏度高,适用于中药材地龙中41种兽药残留的快速筛查。     

超高效液相色谱-串联质谱法同时测定牛乳中19种β-受体激动剂残留

建立同时检测牛乳基质样品中19 种β-受体激动剂类兽药残留的方法。样品经酸化乙腈溶液提取，利用Oasis PRiME HLB固相萃取小柱通过式净化处理除去磷脂，使用超高效液相色谱-串联质谱仪进行检测。结果表明：经过前处理方法与仪器条件优化后，19 种β-受体激动剂质量浓度在0～10 ng/mL呈良好线性关系（R2≥0.995）；牛乳中19 种β-受体激动剂添加量为0.2～1.0 μg/kg时，加标回收率均为70%～110%，相对标准偏差＜15%。本检测方法前处理简单快捷，具有较高灵敏度和稳定性，可以满足牛乳中β-受体激动剂类兽药残留的快速检测。     

QuEChERS-超高效液相色谱-串联质谱法测定牛乳中6种农药残留

建立超高效液相色谱-串联质谱法检测牛乳中6种农药残留量的方法.用乙腈对牛乳进行提取,应用QuEChERS方法进行净化处理,氮吹后复溶,采用C18色谱柱梯度洗脱方式进行液相色谱分离,乙腈和体积分数0.1％甲酸-水溶液为流动相,采用电喷雾离子源正离子模式、多反应监测模式进行检测,外标法定量.结果表明:在1.0～40.0μg...     

QuEChERS-UPLC-MS/MS快速测定生鲜牛乳中的氟喹诺酮类药物残留

本试验建立了生鲜牛乳中8种氟喹诺酮类药物的超高效液相色谱串联质谱的测定方法。生鲜牛乳经QuEChERS萃取剂提取,QuEChERS净化剂净化后,经氮气流吹干浓缩后,以超高效液相色谱串联质谱测定,稳定同位素内标法定量。本方法对氟喹诺酮类药物的测定线性范围为2.0～100 μg/kg。在2.0、10、100 μg/kg低、中、高3个浓度的回收率为80%～120%。批内、批间精密度小于20%。本方法简便、快速、灵敏,适用于生鲜牛乳中氟喹诺酮类药物残留的大批量筛选和定量测定。     

A one-tube nested polymerase chain reaction for the detection of mycobacterium bovis in spiked milk samples: an evaluation of concentration and lytic techniques.

The objective of this study was to evaluate the use of a one-tube nested polymerase chain reaction (OTN PCR) with 5 concentration and lytic treatments for the detection of Mycobacterium bovis in experimentally inoculated milk samples (spiked samples). OTN PCR and the following treatments were tested in inoculated samples: 1) centrifugation; 2) C18-carboxypropylbetaine + capture resin 1 + Proteinase K (CB18-CH-PK); 3) centrifugation + capture resin 1 + Proteinase K; 4) centrifugation + capture resin 2 + Proteinase K; and 5) centrifugation + immunomagnetic separation (IMS). The OTN PCR and the 5 treatments were evaluated in 2 different sets of spiked milk samples. One set consisted of 10-fold serial dilutions of a phenol-killed M. bovis in milk to final concentrations ranging from 5 to 50,000 cells/ml of milk. The other set of samples consisted of 2.5 serial dilutions of milk spiked with M. bovis to final concentrations ranging from 20.5 to 5,000 cells/ml of milk. Each treatment was repeated 5 times at each cell concentration. CB18-CH-PK and IMS were significantly more sensitive than other treatments. The lowest detection limit for these techniques was 20-50 cells/ ml of spiked milk. The specificity of OTN PCR in this study was high as demonstrated by the lack of DNA amplification products when M. bovis cells were not present in the samples. [The OTN PCR used in conjunction with CB18-CH-PK or IMS could be effectively used as a diagnostic and/or screening test for the detection of M. bovis in milk from herds with bovine tuberculosis.]     

PRIME HLB固相萃取/超高效液相色谱-串联质谱法测定乳制品中头孢菌素类药物残留

建立牛乳、酸乳和乳粉3 种基质乳制品中采用超高效液相色谱-串联质谱（ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS）同时检测4 种头孢菌素类药物残留的方法。以5%甲酸乙腈溶液进行提取,经Oasis PRIME HLB固相萃取柱净化,氮吹后复溶,采用电喷雾离子源正离子模式及多反应监测模式进行检测。结果表明：牛乳和酸乳中头孢氨苄、头孢匹林、头孢洛宁和头孢喹肟的定量限为4 μg/kg,乳粉中为32 μg/kg     

Development of Risk Warning Method of Veterinary Drug Residues in Raw Milk Based on Shewhart Control Chart

The aim of this study was to develop a dynamic risk warning method of veterinary drug residues in raw milk because of dynamic changes of raw milk. Risk warning methods of veterinary drug concentration above MRLs, abnormal detection rates and average-standard deviation were developed based on theory of Shewhart control chart. Veterinary drug residues data of 1000 milk samples collected from a large dairy company were analyzed with Shewhart control charts and no risk warning were found. Abnormality of detection rate and average were assumed and also analyzed in this study.     

Improved detection of Mycobacterium avium subsp. paratuberculosis In milk by immunomagnetic PCR

The potential use of a novel immunomagnetic PCR (IMS-PCR) technique as a rapid method to screen milk samples for the presence of Mycobacterium avium subsp. paratuberculosis (M. ptb) was assessed. Immunomagnetic separation (IMS) for M. ptb, developed at Queen's University, Belfast, was applied to milk samples prior to IS900 PCR in order to selectively concentrate any M. ptb cells present and, at the same time, separate the cells from constituents of milk likely to inhibit subsequent PCR. This increased the sensitivity of IS900 PCR. IMS-PCR sensitivity could be further increased by initial centrifugation (2500 g for 20 min) of larger volumes of milk (10 and 50 ml), and resuspension of the sediment into a 1 ml volume appropriate for IMS treatment. Following IMS, template DNA for IS900 PCR was obtained by heating the bead-cell suspension in a thermal cycler at 100 degrees C for 15 min. It was estimated that the IMS-PCR assay could detect approximately 10(3)CFU of M. ptb per 50 ml of milk (equivalent to 20 CFU/ml), whereas the minimum detection limit of direct IS900 PCR was estimated at 10(5)CFU of M. ptb per 50 ml (equivalent to 2000 CFU/ml). A blind trial was carried out in which a total of 40 spiked (10(6)CFU M. ptb) and unspiked, raw and laboratory-pasteurised milk samples were independently tested by IMS-PCR and conventional IS900 PCR. IMS-PCR correctly identified 97. 5% of milk samples (sensitivity 100%, specificity 95%), including spiked milk samples before and after laboratory-pasteurisation. One false positive result was obtained which may have resulted from carryover between samples during the IMS procedure. Conventional IS900 PCR correctly identified only 72.5% of the same 40 milk samples (sensitivity 23%, specificity 100%). IMS-PCR was also shown to be capable of detecting natural M. ptb infection in raw sheep's milk, and raw and commercially pasteurised cows' milk.     

牛奶中粘菌素和杆菌肽残留的固相萃取超高效液相色谱-串联质谱法测定

建立了牛奶中粘菌素和杆菌肽药物残留的固相萃取-超高效液相色谱-串联质谱测定方法,样品用4%三氯乙酸乙腈溶液提取,经乙醚除脂,HLB固相萃取柱净化,相色谱-串联质谱法分析,外标法定量。结果表明：粘菌素和杆菌肽在20~2 000μg/L浓度范围内呈现良好线性,R2均大于0.998;方法检出限为5μg/kg,定量限为10μg/kg;粘菌素和杆菌肽分别在10~100μg/kg和10~1 000μg/kg浓度添加范围内的平均回收率为84%~110%,批内、批间RSD均小于20%。该方法具有简便快捷、灵敏度高、定性准确等优点,能够满足牛奶中其残留检测有关法规的要求。     

液相色谱串联质谱法测定鸡蛋、牛奶和羊奶中泰乐菌素A残留的研究

建立了鸡蛋、牛奶和羊奶中泰乐菌素A残留的液相色谱-串联质谱法.样品经乙腈提取后,Prime HLB固相萃取柱净化,以0.1％甲酸水和乙腈为流动相,液相色谱-串联质谱法测定,内标法定量.试验结果表明:泰乐菌素A在1～100 ng/mL浓度范围内线性关系良好,相关系数r大于0.99;在鸡蛋、牛奶和羊奶中的检测限为2 ng/...