饲料中黄霉素A的测定

本试验建立了高效液相色谱法测定饲料中黄霉素A的方法。饲料中的黄霉素经提取,并用C18小柱净化后,对其进行高效液相色谱测定。此方法黄霉素定量限为2mg/kg,黄霉素A定量限为1.5mg/kg。黄霉素添加浓度为2、3、5mg/kg时,黄霉素A的回收率在88.5%～113.2%之间,变异系数在2.2%～5.1%之间。     

高效液相色谱-串联质谱法测定饲料中地克珠利的含量

建立了一种测定饲料中地克珠利的高效液相色谱-串联质谱方法。以乙腈提取样品中的待测物,正己烷除脂,离心后用高效液相色谱-串联质谱仪,选择多反应监测(MRM)、负离子模式进行定性和定量分析。结果表明,地克珠利在0.5~100 ng/m L浓度范围内线性关系良好,线性相关系数≥0.999,检出限为0.1μg/kg,定量限为0.5μg/kg。地克珠利在0.5、1和5μg/kg三个添加水平下,三种饲料的平均加标回收率在79.2%~94.5%之间,相对偏差在1.7%~14.3%之间。本方法抗干扰能力强,操作简便,灵敏度高,适用于饲料中地克珠利的测定。     

液相色谱串联质谱法测定饲料中的盐酸大观霉素

本文研究了液相色谱和液相色谱-串联质谱检测饲料中大观霉素药物残留的方法,此方法简便、快捷,是一种可靠的检测方法,适用于对饲料中大观霉素进行确证分析。饲料中大观霉素的定量限为:2mg/kg,当添加量为2、20、50mg/kg三个添加浓度时回收率分别为70.06%～107.6%、70.5%～99.5%、70.1%～103.6%,批内批间变异系数小于20%,线性范围及定量限也在合理范围内。     

超高效液相色谱-串联质谱法测定饲料中的己烯雌酚

本文建立了饲料中己烯雌酚的高效液相色谱—串联质谱检测方法(UPLC-MS/MS)。色谱条件:色谱柱为ACQUITY UPLC BEH C18柱2.1mm×50mm1.7μm;流动相为乙腈—水(50:50,v/v),流速0.2mL/min;进样体积10μL;柱温35℃。采用负电喷雾离子源,在多反应监测(MRM)模式下进行分析,外标法定量,3对定性离子对分别为:m/z320.90151.85、320.90256.92和320.90193.90,定量离子对为320.90151.85。在0.1～500μg/L浓度范围内呈良好的线性,相关系数r0.999。在1、5、20mg/kg3个添加水平,平均回收率75.2%～97.6%,日内变异系数在2.1%～6.3%之间,日间变异系数在3.2%～9.7%,检测限为10μg/kg。     

超高效液相色谱——串联质谱法测定饲料中的氯霉素

建立了饲料中氯霉素残留的超高效液相色谱一串联质谱检测方法（UPLC-MS／MS）。用甲醇溶解试样,离心、过膜后,采用负电喷雾离子源,在多反应监测（MRM）模式下进行分析,外标法定量。三对定性离子对（m／z）分别为：320．90〉151．85、320．90〉256．92和320．90〉193．90,定量离子对为320．90〉151．85。在0．1～500μg/L浓度范围内,呈良好的线性,相关系数〉0．99。在0．1、5、20mg／kg三个添加水平,平均回收率75．2％～97．6％,日内变异系数在1．1％～4．3％之间,日间变异系数在3．8％～8．6％之间,检测限为10gg／kg。     

高效液相色谱-串联质谱法测定饲料中三聚氰胺

本研究建立了高效液相色谱-串联质谱(LC-MS/MS)测定饲料中三聚氰胺含量的方法。饲料用三氯乙酸和乙酸铅溶液提取,再经PCX固相萃取柱净化,HILIC色谱柱分离、电喷雾离子化(ESI~+)和选择反应监测(SRM)方式采集,并以~(15)N_3-三聚氰胺为同位素内标定量。该方法的检出限为1 μg/kg;三聚氰胺的测定在1～50ng/mL时具有良好的线性关系;配合饲料、浓缩饲料、预混饲料中的平均回收率分别为97.5%、98.9%和98.0%,平均变异系数分别为4.3%、4.1%和4.3%。通过与外标法比较,该方法定量准确可靠,更加适合用作饲料中三聚氰胺的定量测定。     

液相色谱-串联质谱法测定饲料中氟喹诺酮类药物

本试验建立了饲料中氟喹诺酮类药物添加剂的液相色谱-串联质谱检测方法 。样品经含1%甲酸的甲醇溶液提取,HLB固相萃取柱净化,0.22μm滤膜过滤后用液相色谱-串联质谱检测法测定,外标法定量。该法适用于配合饲料、浓缩饲料、预混合饲料和鱼饲料等饲料中盐酸环丙沙星、恩诺沙星、诺氟沙星、氧氟沙星、甲磺酸达氟沙星、盐酸沙拉沙星含量的测定。6种药物的检测限为60.0μg/kg,定量限为200.0μg/kg。该方法步骤简单、易于操作,准确度、精密度和灵敏度高,符合我国对饲料中氟喹诺酮类药物含量检测要求。     

超高效液相色谱-串联质谱法测定饲料中五氯酚的含量

试验通过超高效液相色谱-串联质谱法（UPLC-MS/MS）,建立1种适用于饲料中五氯酚的定量检测分析方法,以期为饲料中五氯酚残留量的检测分析提供参考。试验样品经粉碎过筛后于离心管中,采用5%三乙胺-乙腈-水溶液作为提取液进行涡旋、超声提取。提取液经MAX固相萃取柱净化后,采用4%甲酸-甲醇溶液洗脱后氮吹至1 mL左右,使用水定容至2 mL混匀,过膜上机测定。采用C18 (100 mm×2.1 mm,1.8μm)色谱柱分离,质谱多重反应监测,外标法定量。结果显示,该方法在0.5～20.0μg/L浓度内呈良好的线性关系（R2=0.999 1）,检出限为1μg/kg,定量限为2μg/kg;加标浓度在1～20μg/L范围时,平均回收率在72.4%～109.6%之间,相对标准偏差（RSD）为3.37%～6.24%(n=6)。研究表明,该方法操作简单、试验重复性好、准确率、稳定性高,适用于饲料中五氯酚含量的定量测定分析。     

液相色谱—串联质谱法测定猪配合饲料中吉他霉素

采用液相色谱-串联质谱仪测定猪配合饲料中吉他霉素。试样中的吉他霉素经20/80(V/V)甲醇/水提取,取部分上清液稀释,用美国waters公司生产的固相萃取柱(6cc/200mg Oasis HLB)净化,氮气吹干,初始流动相复溶,上液相色谱-串联质谱仪测定,保留时间和离子丰度比定性,外标法定量。本方法中吉他霉素检测限为0.01mg/kg、定量限为0.05mg/kg。吉他霉素的线性范围为5~200 ng/mL,相关系数r大于0.999。在0.05~50 mg/kg的添加水平上,吉他霉素的平均回收率为63.3%~106.6%,相对标准偏差为1.6%~10.3%。     

超高效液相色谱串联质谱法测定饲料中大观霉素的研究

实验建立了测定饲料中大观霉素的超高效液相色谱串联质谱方法。样品以甲醇草酸溶液(80∶20,V/V)提取后经ACQUITY UPLC Hilic C18柱(2.1 m×50 mm,1.7μm)分离,在选定质谱条件下进行检测,外标法定量。结果表明,大观霉素浓度在0.2～10μg/mL时与峰面积呈良好的线性关系,相关系数均大于0.999,平均回收率为64.10%～98.54%,批内变异系数为5.54%～15.10%,批间变异系数为2.92%～11.89%。     

气质联用检测饲料中氯霉素的方法研究

用乙腈／4％氯化钠（1：1）混合液提取饲料中氯霉素,采用两种方法对提取物进行净化分离。一种方法用Oasis HLB固相萃取柱代替传统的C18柱对提取物进行净化富集,另一种方法不使用固相萃取柱。净化后的提取物用BSTFA＋TMCS进行衍生,气相色谱-离子肼质谱联用仪检测,采用SIM模式电离,选择离子为225、208、178,通过对净化、提取及质谱条件的优化,该方法对不同饲料样品中氯霉素的加标回收率在76.1％-102.3％,相对标准偏差小于10％,方法的检出限为0.1mg/g。     

气相色谱/质谱法测定饲料中三唑仑的含量

本实验建立了检测饲料中三唑仑的气相色谱/质谱法。样品经有机溶剂提取,阳离子固相萃取小柱净化后注入气相色谱质谱仪进行测定,并且经质谱确证。结果表明,三唑仑在0.1～5.0μg/mL范围内具有良好的线性关系,方法的回收率、精密度较高。     

Urinary free metanephrines measurement in dogs with adrenal gland diseases using a new simple liquid chromatography tandem mass spectrometry method

Measurement of urinary metanephrines in spot samples is used for the diagnosis of canine pheochromocytoma (PC). We describe a simple analytical method based on liquid chromatography tandem mass spectrometry (LC-MS/MS) for measuring free metanephrine (MN) and normetanephrine (NMN) in spot urine samples. Using the developed method, we evaluated the stability of urinary free-MN and free-NMN at various storing conditions. In addition, we assessed the feasibility of urinary free-MN and -NMN measurement for diagnosing PC. Urine samples were mixed with stable isotope internal standards and thereafter purified by ultrafiltration. The purified samples were analyzed by LC-MS/MS in the multiple reaction monitoring mode after separation on a multimode octa decyl silyl column. The coefficient of variation of free-MN and -NMN measurement was 7.6% and 5.5%, respectively. The linearity range was 0.5–10 µg/l for both analytes. Degradation was less than 10% for both analytes under any of the storage conditions. The median free-NMN ratio to creatinine of 9 PC dogs (595, range 144–47,961) was significantly higher (P<0.05) than that of 13 dogs with hypercortisolism (125, range 52–224) or 15 healthy dogs (85, range 50–117). The developed method is simple and may not require acidification of spot urine. The results of this preliminary retrospective study suggest that the measurement of urinary free metanephrines is a promising tool for diagnosing canine PC.     

Sporozoite proteome analysis of Cryptosporidium parvum by one-dimensional SDS-PAGE and liquid chromatography tandem mass spectrometry

Despite the development of new technologies, new challenges still remain for large scale proteomic profiling when dealing with complex biological mixtures. Fractionation prior to liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis is usually the preferred method to reduce the complexity of any biological sample. In this study, a gel LC-MS/MS approach was used to explore the stage specific proteome of Cryptosporidium (C.) parvum. To accomplish this, the sporozoite protein of C. parvum was first fractionated using SDS-PAGE with subsequent LC-MS/MS analysis. A total of 135 protein hits were recorded from 20 gel slices (from same gel lane), with many hits occurring in more than one band. Excluding all non-Cryptosporidium entries and proteins with multiple hits, 33 separate C. parvum entries were identified during the study. The overall goal of this study was to reduce sample complexity by protein fractionation and increase the possibility of detecting proteins present in lower abundance in a complex protein mixture.     

Quantitative determination of 12-hydroxyeicosatetraenoic acids by chiral liquid chromatography tandem mass spectrometry in a murine atopic dermatitis model

Atopic dermatitis, one of the most important skin diseases, is characterized by both skin barrier impairment and immunological abnormalities. Although several studies have demonstrated the significant relationship between atopic dermatitis and immunological abnormalities, the role of hydroxyeicosatetraenoic acids (HETE) in atopic dermatitis remains unknown. To develop chiral methods for characterization of 12-HETE enantiomers in a 1-chloro-2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis mouse model and evaluate the effects of 12-HETE on atopic dermatitis, BALB/c mice were treated with either DNCB or acetone/olive oil (AOO) to induce atopic dermatitis, after which 12(R)- and 12(S)-HETEs in the plasma, skin, spleen, and lymph nodes were quantified by chiral liquid chromatography-tandem mass spectrometry. 12(R)- and 12(S)-HETEs in biological samples of DNCB-induced atopic dermatitis mice increased significantly compared with the AOO group, reflecting the involvement of 12(R)- and 12(S)-HETEs in atopic dermatitis. These findings indicate that 12(R)- and 12(S)-HETEs could be a useful guide for understanding the pathogenesis of atopic dermatitis.     

高效液相色谱-串联质谱法测定动物性食品中硝基呋喃类代谢物残留

采用同位素内标稀释技术建立了动物性食品中呋喃唑酮、呋喃它酮、呋喃西林、呋喃妥英代谢物的测定方法,在酸性条件下水解,2-邻硝基苯甲醛溶液(2-NBA)进行衍生化,乙酸乙酯提取,固相萃取柱OasisHLB富集净化,三级四极串联电喷雾质谱正离子模式测定,同位素内标定量。本方法检出限0.1μg/kg,加标回收率65.3%～83.7%,相对标准偏差3.1%～12.6%。该方法灵敏度高、重现性好、定性准确可靠。通过对实际样品的检测,证明可用于动物源性食品中四种硝基呋喃代谢物残留的测定。     

高效液相色谱串联质谱法测定渔业水体及渔业饲料中的五氯苯酚

本文建立了一种简单、快速测定渔业水体和渔业饲料中五氯苯酚的液相色谱串联质谱分析方法。渔业水体采取固相萃取进行富集净化,渔业饲料样品经氨化乙腈提取,MAX固相萃取小柱净化,质谱采用选择反应监测负离子模式测定进行分析。结果表明:方法线性为0.5～50 ng/mL,相关系数大于0.9999;渔业水体的检出限(LOD)和定量限(LOQ)为0.05μg/L和0.1μg/L,渔业饲料的LOD和LOQ为0.8μg/kg和1.6μg/kg,该方法在水样和渔业饲料样品中的平均加标回收率为78.6%～92.1%。采用该方法对长沙市周边的湖泊和池塘地表水和渔业饲料样品进行检测,在水样中测得五氯苯酚浓度为0.64～1.22μg/L。     

气相色谱质谱法测定水产饲料中16种多环芳烃的方法研究

为满足水产饲料中多环芳烃的测定需要,建立了以苊-D10、蓝屈-D12和苯并(a)芘-D12为内标物,气相色谱质谱法测定水产饲料中16种多环芳烃的定性定量方法.通过考察提取溶剂、提取方式和净化方法等前处理过程,优化色谱质谱条件,得到最佳实验方法.并对实际样品进行测定,考察该方法的适应性.结果表明:在2～1000 ng/m...     

超高效液相色谱-串联质谱法测定饲料中维生素D3

为建立一种快速测定饲料中维生素D3的超高效液相色谱-串联质谱检测方法,本研究优化了皂化和提取过程,增加了固相萃取柱净化,采用内标定量,旨在解决饲料中维生素D3检测过程中干扰严重无法准确定量、检测效率低和不适用饲料原料的问题.结果 表明:本方法回收率为70.1％～93.6％,批内相对标准偏差为3.8％～8.3％,定量限为...     

高效液相色谱-串联质谱法测定熟制鸡肉制品中金刚烷胺

建立了高效液相色谱-串联质谱(HPLC-MS/MS)测定熟制鸡肉制品中金刚烷胺的分析方法。样品用乙腈提取,PXC小柱净化,经C18色谱柱分离,以电喷雾离子源(ESI)在正离子多反应监测(MRM)模式下进行测定,内标法定量。金刚烷胺的检出限为0.05μg/kg,定量限为0.15μg/kg,在0.3~150μg/L范围内线性关系良好,相关系数r2为0.9992。对于4种不同的熟制鸡肉制品,在4个加标水平下的平均回收率范围为87.2%~94.8%,批内精密度(n=6)为6.7%~10.0%,批间精密度(n=3)为8.5%~13.6%。该方法灵敏度高,准确性好,适用于熟制鸡肉制品中金刚烷胺残留量的测定。