高效液相色谱-串联质谱法测定动物源食品中3-甲基喹喔啉-2-羧酸和喹喔啉-2-羧酸残留

建立了动物源食品中喹喔啉类药物代谢残留标识物3-甲基喹喔啉-2-羧酸和喹喔啉-2-羧酸的高效液相色谱-串联质谱检测方法。样品在酸性环境水解,经乙酸乙酯、磷酸盐缓冲液依次提取,Oasis MAX固相萃取小柱净化,用Waters Xterra MS C18柱(150 mm×2.1 mm, 5 μm)分离,以甲醇-0.2%甲酸为流动相梯度洗脱,采用多反应监测(MRM)正离子模式检测,内标法定量。各物质在1.0～20.0 μg/L范围内线性关系良好,相关系数均不低于0.9996; 3-甲基喹喔啉-2-羧酸和喹喔啉-2-羧酸在0.1、0.2、1.0 μg/kg加标水平的回收率为62.4%～118%,相对标准偏差为1.48%～28.1%;定量限(以信噪比≥10计)为0.1 μg/kg。该方法简单、灵敏、稳定,可满足猪肉、猪肝、鸡肉、鸡肝、鱼、虾等动物源食品中3-甲基喹喔啉-2-羧酸和喹喔啉-2-羧酸残留的检测与确证需要。     

高效液相色谱法测定动物组织中3-甲基喹喔啉-2-羧酸残留量

本文建立了猪、鸡、鱼肌肉及猪、鸡肝脏组织中喹乙醇代谢残留标识物3-甲基喹喔啉-2-羧酸残留量的高效液相色谱分析方法.样品在酸性环境水解,经乙酸乙酯、磷酸盐缓冲溶液依次提取,Oasis MAX固相萃取柱净化,高效液相色谱紫外测定(HPLC-UV).3-甲基喹喔啉-2-羧酸标准曲线相关系数(r2)为0.9992(10～1 000 μg/L);不同动物组织样品中3-甲基喹喔啉-2-羧酸工作曲线相关系数(r)为0.9995～0.9997(2～100 μg/kg).在2～100 μg/kg浓度范围,3-甲基喹喔啉-2-羧酸回收率为69%～104%,日内相对标准偏差＜15%,日间相对标准偏差＜20%.检出限(CCα)为1.2～4.3 μg/kg,定量限(CCβ)为2.0～5.6 μg/kg.     

双柱固相萃取净化-液相色谱-串联质谱法测定牛奶和奶粉中链霉素和双氢链霉素残留量

建立了双柱固相萃取净化-液相色谱-串联质谱(HPLC-MS/MS)测定牛奶和奶粉中链霉素和双氢链霉素残留量的分析方法。样品用H3PO4溶液提取,三氯乙酸沉淀蛋白,苯磺酸型和羧酸型固相萃取柱净化,经Atlantis C18色谱柱分离,以电喷雾离子源在正离子多反应监测(MRM)模式下进行测定。牛奶中链霉素和双氢链霉素的方法检出限均为4μg/kg,定量限均为10μg/kg,奶粉中链霉素和双氢链霉素的方法检出限均为30μg/kg,定量限均为80μg/kg,方法回收率为80%~86%,相对标准偏差为5.9%~11.5%。本方法适用于牛奶和奶粉中链霉素和双氢链霉素残留量的测定。     

动物组织中卡巴氧和喹乙醇以及相关代谢产物的液相色谱-串联质谱检测方法

建立了牛、猪肌肉和肝脏组织中卡巴氧(CBX)和喹乙醇(OQX)以及相关代谢产物--脱氧卡巴氧(DCBX)、喹噁啉-2-羧酸(QCA)和3-甲基喹噁啉-2-羧酸(MQCA)残留的LC-MS/MS的检测方法.组织样品中的卡巴氧用乙腈-乙酸乙酯(体积比1 : 1)溶液提取;代谢产物的提取则是经适当处理后的样品加入Protease蛋白酶进行酶解,后采用阴离子交换固相萃取柱Oasis MAX进行净化和富集.分析样品以甲酸溶液(体积分数为 0.1%)-甲醇-乙腈为流动相,经Inertsil ODS-3色谱柱分离,在LC-MS/MS多反应监测模式下进行定性、定量分析,采用正离子扫描.CBX、DCBX、QCA和MQCA的定量下限均为0.5 μg/kg,猪、牛肌肉和肝脏在0.5 ～5.0 μg/kg添加水平的平均回收率在76% ～97%之间,相对标准偏差(n＝10)在2.9% ～16.9%之间.     

水产品中喹烯酮和喹赛多及其主要代谢物残留的HPLC-MS/MS检测方法研究

以草鱼、南美白对虾、中华绒鳌蟹为样品,建立了喹烯酮(QCT)和喹赛多(CYA)及其主要代谢物脱二氧喹烯酮(BDQCT)、3-甲基喹啉-2-羧酸(MQCA)、脱二氧喹赛多(BDCYA)和喹啉-2-羧酸(QCA)多残留的高效液相色谱-串联质谱(HPLC-MS/MS)确证检测方法。组织样品经乙腈-乙酸乙酯(1∶1)、盐酸溶液分步提取,Oasis MAX固相萃取柱净化,以甲醇、乙腈和0.1%甲酸溶液为流动相,经Waters XBridge C18色谱柱分离后,采用HPLC-MS/MS仪进行测定。采取正离子选择反应监测模式检测,外标法定量。结果表明,喹烯酮和喹赛多及其主要代谢物的响应值与其质量浓度在2~500μg/L范围内线性关系良好。在加标浓度为5~50μg/kg范围内,6种待测物的平均回收率为76.3%~94.2%,相对标准偏差为4.2%~11.7%。方法的检出限为0.5~1.6μg/kg,定量下限为2.0~5.0μg/kg。该方法适用于水产品中QCT和CYA及其主要代谢物残留的确证检测和同时定量分析。     

高效液相色谱-串联质谱法检测猪肉中3-甲基喹喔啉-2-羧酸残留

建立了高效液相色谱-串联质谱同时定量和确证猪肉中3-甲基喹喔啉-2-羧酸（MQCA）残留量的检测方法。试样用0.3 mol/L盐酸溶液水解提取，加入乙腈和乙酸乙酯萃取，再用0.1 mol/L氢氧化钠溶液反萃取，阴离子交换固相萃取柱净化，经Agilent Eclipse Plus C₁₈柱（50 mm×3.0 mm，1.8 μm）分离，采用液相色谱-串联质谱仪检测，基质匹配添加标准曲线定量。MQCA在1.0~50 μg/L范围内线性相关系数大于0.99，在0.5、1.0、5.0 μg/kg加标水平下其回收率为90.5%~119.6%，相对标准偏差为3.14%~4.22%。方法可用于猪肉中MQCA残留量的快速定量和确证检测。     

气相色谱-负离子化学源质谱法分析牛奶饮品和奶粉中19种有机磷农药残留

将气相色谱-负离子化学源质谱法(GC-NCIMS)应用于牛奶饮品和奶粉中19种有机磷农药残留的同时分析。牛奶饮品和奶粉经乙腈提取剂超声提取、Florisil硅藻土和中性氧化铝双净化剂同时净化及正己烷-乙酸乙酯(体积比1∶1)混合洗脱剂洗脱后,以三苯基磷酸酯为内标物,采用GC-NCI MS的选择离子监测方式(SIM)定性与定量分析。当牛奶饮品和奶粉的加标浓度水平为20、100、500μg/kg时,平均加标回收率为64.5%~129%,相对标准偏差为2%~20%;除喹硫磷的方法检出限(MDL)为2.4μg/kg外,其余18种有机磷农药的MDL均小于1.0μg/kg;线性范围为10~500μg/kg,相关系数均大于0.9988,此分析方法成功地应用于牛奶饮品和奶粉中多种痕量有机磷农药残留的分析。     

QuEChERS-超高效液相色谱-串联质谱法快速测定鱼肉中22种磺胺类药物残留

结合QuEChERS前处理技术,提出了测定鱼肉中22种磺胺类残留的超高效液相色谱-串联质谱法。样品用含0.1%(体积分数,下同)甲酸的乙腈溶液提取后,经QuEChERS试剂盒净化。净化液在Agilent ZORBAX Eclipse Plus C18色谱柱上分离,以0.1%甲酸溶液-甲醇为流动相进行梯度洗脱。采用电喷雾正离子源及计划式多反应监测模式进行测定,以内标法定量。磺胺硝苯、磺胺、磺胺喹噁啉的线性范围为0.5~50μg·L-1,检出限(3S/N)为0.5μg·L-1;其他19种磺胺类兽药的线性范围为0.1~50μg·L-1,检出限(3S/N)为0.1μg·L-1。加标回收率在78.2%~118%之间,测定值的相对标准偏差(n=6)在3.4%~19%之间。方法用于鱼肉中多种磺胺类药物残留的快速测定,结果与标准方法测定结果一致。     

凝胶渗透色谱-超高效液相色谱-串联质谱法测定奶及奶粉中黄曲霉毒素M_1

建立了用凝胶渗透色谱-超高效液相色谱/串联三重四级杆质谱测定牛奶中黄曲霉毒素M_1的方法。方法以乙腈超声提取,凝胶渗透色谱净化后,以乙腈-0.1%甲酸(3:7,V/V)为流动相,UPLC BEH C18分离,ESI+模式质谱检测,外标法定量。黄曲霉毒素M_1在0.1~4.0μg/L范围内线性关系良好,相关系数r为0.9955,检出限为0.01μg/kg,定量限为0.05μg/kg。牛奶样品在0.1,0.2,0.5μg/kg 3个加标浓度下,黄曲霉毒素M_1的回收率为72.4%~92.2%,相对标准偏差为4.0%~7.8%。     

凝胶净化/高效液相色谱-串联质谱法检测辣椒制品及肉制品中多种脂溶性着色剂

建立了凝胶渗透色谱净化/高效液相色谱-串联质谱测定辣椒制品和肉制品中苏丹橙G、甲基黄、对位红,柑桔红2号,苏丹红G,苏丹Ⅰ,苏丹Ⅱ,苏丹Ⅲ,苏丹红7B,苏丹红B和苏丹Ⅳ的分析方法。样品经乙酸乙酯或乙腈-乙酸乙酯溶液提取后采用凝胶渗透色谱净化,通过ACQUITY HPLC BEH C18色谱柱以体积分数0.1%甲酸-体积分数0.1%甲酸甲醇溶液作流动相梯度洗脱分离,采用多反应监测模式进行检测。目标分析物使用同位素内标苏丹Ⅰ-D5和苏丹Ⅳ-D6定量,11种待测物质量浓度在10~500 ng/mL范围呈良好线性关系,相关系数大于0.99,方法的定量下限均达到5μg/kg。空白样品在5,10,20μg/kg 3个加标水平下的平均回收率为80.7%~100.9%,相对标准偏差(n=10)均小于10%。     

Development of a high-performance liquid chromatography method for the simultaneous quantification of quinoxaline-2-carboxylic acid and methyl-3-quinoxaline-2-carboxylic acid in animal tissues

A method of high-performance liquid chromatography with UV detection has been established for simultaneous quantitative determination of quinoxaline-2-carboxylic acid (QCA) and methyl-3-quinoxaline-2-carboxylic acid (MQCA), the marker residues for carbadox (CBX) and olaquindox (OLA), respectively, in the muscles and livers of porcine and chicken and in the muscle of fish. Tissue samples were subject to acid hydrolysis followed by liquid-liquid extraction and Oasis MAX solid-phase extraction clean-up. The method was validated according to the EU Commission Decision 2002/657/EC. The decision limits (CCalpha) were 0.7-2.6microg/kg and the detection capabilities (CCbeta) were 1.3-5.6microg/kg for QCA and MQCA in tissues. The recoveries of QCA and MQCA, spiked at levels of 2-100microg/kg, were from 70 to 110%; the relative standard deviation values were <20%. This simple, fast and economic method could be applied to the monitoring for the possible misuse of CBX and OLA in animal edible tissue samples.     

Novel surface molecularly imprinted sol-gel polymer applied to the online solid phase extraction of methyl-3-quinoxaline-2-carboxylic acid and quinoxaline-2-carboxylic acid from pork muscle

A new molecularly imprinted polymer (MIP), selective for major metabolites of quinoxaline-1,4-dioxides was firstly prepared by combining surface molecular imprinting technique with the sol–gel process. Methyl-3-quinoxaline-2-carboxylic acid (MQCA) was used as template, 3-aminopropyltriethoxysilane as functional monomer, and tetraethoxysilicane as cross-linker. The MIP was characterized by Fourier transform infrared and evaluated through static adsorption experiments. The results indicated that MIP had high adsorption capacity, fast binding kinetics for MQCA, and the polymer showed a high degree of cross-reactivity for quinoxaline-2-carboxylic acid (QCA). The MIP was then applied as a selective sorbent in an online solid phase extraction (SPE) coupled with high-performance liquid chromatography (HPLC). For a 50-mL sample solution, enrichment factors of 1,349 and 1,046 for QCA and MQCA, respectively, and limits of detection (S/N = 3) of 0.8 and 2 ng L⁻¹ for QCA and MQCA, respectively, were obtained (corresponding to 0.02 and 0.04 ng g⁻¹ in solid samples for final 100 mL of sample solutions of 5 g of pork). The sample preparation protocol was simplified and only included one step extraction with acetonitrile (MeCN) after the release of target analytes through acidic hydrolysis without further sample cleanup. The new MIP-SPE-HPLC method was successfully applied to the quantification of trace QCA and MQCA in pork muscle with good recoveries ranging from 67% to 80% and RSD below 8%.     

超高效液相色谱-串联质谱测定水产品中的卡巴氧、喹烯酮、乙酰甲喹及其代谢物

建立了超高效液相色谱-串联质谱法测定水产品中卡巴氧(CBX),喹烯酮(QCT)、乙酰甲喹(MEQ)、哇噁啉-2-羟酸(QCA),3-甲基喹噁啉-2-羧酸(MQCA) 5种化合物残留的分析方法.样品分别采用乙酸乙酯-乙腈(50:50)混合溶液、磷酸盐缓冲液分步提取,正己烷净化,以甲醇-乙腈(11:3)混合溶液和0.1%甲...     

Raman spectroscopic quantification of milk powder constituents

Raman spectroscopy has significant potential for the quantification of food products. Milk powder is an important foodstuff and ingredient that is produced on large scale (over 20 million tonnes per annum). Raman spectroscopy, unlike near- and mid-infrared spectroscopies, has not been used extensively to quantify milk powder constituents. The effect of sample presentation on spectroscopic calibrations of protein and fat for 136 New Zealand milk powders was assessed using Raman spectroscopy. Prediction models were produced to quantify a protein concentration range of 32.19-37.65% w/w for skim milk powder, and a protein concentration range of 23.34-25.02% w/w and a fat concentration range of 26.26-29.68% w/w for whole milk powder (where ratios of prediction to deviation exceeded 2.6 with one exception). The resultant calibrations were not influenced by sample orientation; the sample temperature during data collection did affect the calibrations. Calcium fortification in the form of calcium carbonate was identified within a sub-set of samples, reinforcing the efficacy of Raman spectroscopy for identifying both crystalline and non-crystalline constituents within milk powder.     

Determination of marker residue of Olaquindox in fish tissue by ultra performance liquid chromatography-tandem mass spectrometry

Methyl-3-quinoxaline-2-carboxylic acid (MQCA) is the last major remaining detectable metabolite of Olaquindox in animal tissue. A rapid, sensitive and specific ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the detection and quantification of MQCA in fish tissue using deuterated quinoxaline-2-carboxylic acid (d(4)-QCA) as internal standard. Various parameters affecting sample preparation, LC separation and MS/MS detection were investigated, and the optimal conditions concerned were determined. Fish tissue samples were subject to hydrochloric acid hydrolysis followed by Oasis MAX solid-phase extraction clean-up; analysis was performed using UPLC coupled to electrospray MS/MS. The chromatographic separation was achieved in less than 5 min. The limit of detection and the limit of quantification were 0.1 and 0.25 ng/g, respectively. The average recoveries of MQCA, spiked at levels of 0.25-50.0 ng/g, were from 92.7 to 104.3%. The relative standard deviation values were <6%. The validated method was successfully applied to analyze 60 batch samples collected from the local market.     

MPT-AES测定奶粉中的Ca和Fe

用微波等离子体(MPT)为激发光源,氩气为等离子体工作气体,用气动雾化进样,采用标准曲线法研究了微波等离子体炬原子发射光谱法(MPT-AES)测定奶粉中Ca、Fe的方法。详细考察了溶液中HCl浓度、HNO3浓度、微波前向功率、载气流量、工作气流量等实验参数对测定的影响,同时考察了共存元素钠、镁、锌对钙和铁发射强度的影响。     

Selective preconcentration and determination of iodine species in milk samples using polymer inclusion sorbent

A method to determine low levels of iodine species namely I⁻ and IO₃⁻ in aqueous samples was developed and applied to milk and milk powder samples. It is based on selective preconcentration of I⁻ in polymer inclusion sorbent (PIS) and neutron activation analysis (NAA) of I⁻ sorbed in PIS. The PIS was found to be highly selective for I⁻ in presence of IO₃⁻ and other anions commonly present in the milk samples. In order to preconcentrate total I⁻ + IO₃⁻ content in the PIS, IO₃⁻ was reduced to I⁻ using a mixture of acetic acid and ascorbic acid. It was found that total iodine content in milk could be determined with epithermal neutron activation analysis (ENAA). A scheme was developed to determine I⁻, IO₃⁻ and total iodine. The developed method was applied to milk reference materials (NIST SRM-1549 and IAEA-RM-153 milk powder) and a commercially available milk powder. The scheme for estimation of iodine in different forms was validated by using reference material NIST SRM-1549.