超高效液相色谱-串联质谱法同时测定人乳中的胆碱、L-肉碱、乙酰基-L-肉碱和牛磺酸

目的建立一种简单、快速、灵敏的可以同时测定人乳中胆碱、L-肉碱、乙酰基-L-肉碱和牛磺酸的超高效液相色谱-串联质谱法。方法样品经甲醇沉淀蛋白、乙醚去除非极性杂质,UPLC BEH Amide色谱柱分离后采用保留时间和多反应离子检测(MRM)定性、定量,同位素内标校正。结果牛磺酸的定量下限(LOQ)为0.02 mg/100 g,胆碱、L-肉碱和乙酰基-L-肉碱的LOQ均为0.003 mg/100 g。标准加入法测定所有被测物的高、中、低三个浓度加标水平的回收率在84.8%~90.3%之间,相对标准偏差(RSD)在1.7%~5.3%之间。4种被测物在各自浓度范围内线性良好,R2均大于0.999。结论本文建立了同时测定人乳中胆碱、L-肉碱、乙酰基-L-肉碱和牛磺酸的超高效液相色谱-串联质谱法。方法前处理简单、快速,样品需要量少;采用质谱检测器同位素内标一对一校正定量,检测结果准确、灵敏。方法可以为人乳中相关营养素含量的调查、研究和为配方奶粉人乳化提供技术支持。     

超高效液相色谱-串联质谱法同时测定人乳中的 胆碱、L-肉碱、乙酰基-L-肉碱和牛磺酸

目的 建立一种新颖、简单、快速、灵敏的同时测定母乳中胆碱、L-肉碱、乙酰基-L-肉碱和牛磺酸的超高效液相色谱-串联质谱法。方法 样品经甲醇沉淀蛋白、乙醚去除非极性杂质,UPLC BEH Amide色谱柱分离后采用保留时间和多反应离子检测（MRM）定性、定量,同位素内标校正。结果 牛磺酸的定量下限（LOQ）为0.02 mg/100g,胆碱、L-肉碱和乙酰基-L-肉碱的LOQ均为0.003 mg/100g。标准加入法测定所有被测物的高、中、低三个浓度加标水平的回收率在84.8 %-90.3 %之间,相对标准偏差（RSD）在1.7 %-5.3 %之间。4种被测物在各自浓度范围内线性良好,r2均大于0.999。结论 本文建立了同时测定母乳中胆碱、L-肉碱、乙酰基-L-肉碱和牛磺酸的超高效液相色谱-串联质谱法。方法前处理简单、快速,样品需要量少;采用质谱检测器同位素内标一对一校正定量,检测结果准确、灵敏。方法可以为母乳中相关营养素含量的调查、研究和为配方奶粉母乳化提供技术支持。     

液相色谱同位素稀释串联质谱法测定牛奶和奶粉中3种硝基咪唑类禁用兽药及其代谢物的残留量

目的 建立了液相色谱同位素稀释串联质谱法同时测定牛奶和奶粉中3种硝基咪唑类禁用兽药(甲硝哒唑、二甲硝咪唑和罗硝哒唑)及其代谢物(羟基甲硝唑和1-甲基-2-羟甲基-5-硝基咪唑)残留量的方法.方法 采用乙腈沉淀样品蛋白,乙酸乙酯提取目标物,强阳离子交换固相萃取柱净化提取液,液相色谱-串联质谱测定,同位素内标法定量.结果 牛奶样品中5种分析物的检测限( LOQ)为0.5～1 μg/kg,奶粉样品中5种分析物的LOQ为2.5 ～5μg/kg.5种分析物在0～50 μg/L的浓度范围内呈良好线性,线性相关系数＞0.995.方法在3个水平的添加回收率在88.3％ ～ 104.4％之间,相对标准偏差在3.67％～8.52％之间.结论 方法采用同位素稀释法定量,回收率高、重现性好,适用于牛奶、奶粉等样品中硝基咪唑类药物残留的定量及确证检测.     

同位素内标-高效液相色谱质谱法测定婴幼儿配方乳粉中维生素B6和生物素

目的建立同位素内标和高效液相色谱串联质谱法(highperformanceliquidchromatographytandem mass spectrometry, HPLC-MS/MS)同时测定婴幼儿配方乳粉中维生素B_6含量(吡哆醛、吡哆醇和吡哆胺)和B_7(生物素)的分析方法。方法样品加入同位素内标后,使用温水溶解,并用高氯酸沉淀蛋白质,上清液过滤后经HSS T3色谱柱分离,三重四极杆质谱仪检测,内标法定量。结果在最优化条件下,维生素B_6和生物素分别在1.0～100μg/L和0.10～10.0μg/L范围内线性关系良好,相关系数均大于0.998;定量限分别为10.0μg/100 g和1.0μg/100g。4种化合物的回收率为86.5%～97.9%,相对标准偏差为3.0%～6.6%。质控样品检测结果表明该方法准确可靠。结论该方法灵敏度高、净化效果好、定量准确,适用于婴幼儿配方乳粉中维生素B_6和维生素B_7的检测。     

液相色谱串联质谱法测定婴幼儿食品中维生素D_3的质量浓度

建立了同位素内标液相色谱串联质谱法测定婴幼儿食品中维生素D_3质量分数。试样加同位素内标后,乙醇-50%氢氧化钾溶液皂化,石油醚萃取,Atlantis T3色谱柱(100 mm×2.1 mm,3μm),甲醇-5 mmol/L甲酸胺溶液作为流动相,梯度洗脱进行液相分离,采用电喷雾正离子方式,多反应选择离子监测,内标法峰面积定量。婴幼儿食品中维生素D_3质量浓度在2~200μg/L范围内线性良好,相关系数r均大于0.99,配方奶粉和米粉在10,50和100μg/kg三个质量分数水平的添加回收率分别为86.1%~107%和86.2%~106%,变异系数分别为4.48%~7.08%和2.10%~4.26%(n=6)。方法的定量限为10μg/kg。方法简便、准确,适用于婴幼儿食品中维生素D_3的检测。     

同位素内标-超高效液相色谱-串联质谱法测定蜂蜜中氯霉素及甲硝唑

目的采用同位素内标-超高效液相色谱-串联质谱法测定蜂蜜中氯霉素及甲硝唑的残留量。方法样品经乙酸乙酯提取,MCS复合型固相萃取柱(500 mg/6 ml)净化,采用ZORBAXSB-C18色谱柱(2.1 mm×100 mm,1.8μm)分离,以甲醇和5 mmol/L乙酸铵溶液(含0.05%甲酸)为流动相进行梯度洗脱,采用电喷雾正/负离子多反应监测模式检测,同位素内标法定量。结果氯霉素、甲硝唑的浓度为0.05~5.00 ng/ml时,线性关系良好,相关系数r0.999。添加0.5、2.0、5.0μg/kg三个不同水平时,氯霉素、甲硝唑的回收率为79.3%~96.7%,相对标准偏差(RSD)为5.5%~14.8%,定量限均为0.15μg/kg,检出限均为0.05μg/kg。结论该方法灵敏度及准确度良好,可应用于日常大批量样品的高灵敏分析。     

液相色谱-串联质谱法测定葡萄酒中赭曲霉毒素A

以赭曲霉毒素B为内标物,建立了应用固相萃取-液相色谱-串联质谱法(SPE-LC-MS/MS)对葡萄酒中赭曲霉毒素A残留量测定的方法。葡萄酒样品经过调节pH值至7.0和C18固相萃取净化的前处理过程后,采用液相色谱-串联质谱法进行测定(正离子方式,多反应监测模式)。方法定量限(LOQ)为2.0g/L。内标法定量计算,在0~10g/L质量浓度范围内线性相关系数0.998。在葡萄酒中分别进行2.0g/L、4.0g/L和8.0g/L三个添加水平的测试,该检测方法回收率范围97.6%~109.7%,相对标准偏差(RSD)3.0%~4.6%。方法简便、快速、准确,可用于葡萄酒中赭曲霉毒素A的定量测定。     

食品中黄曲霉毒素B_1的液相色谱-串联质谱测定法

建立了食品中黄曲霉毒素B1残留量的超高效液相色谱-串联质谱的检测方法。样品经乙腈+水(84+16)提取后,经多功能净化柱净化,超高效液相色谱-串联质谱法检测。本方法定量限为1μg/kg,线性范围为1~20 ng/mL;在黄曲霉毒素B1添加水平为1~10μg/kg时,在玉米样品中的回收率为95%~105%;在酱油样品中的回收率为96%~106%。     

基于通过型固相萃取-高效液相色谱-串联质谱法同时测定水产品中的氯霉素和红霉素

建立通过型固相萃取-高效液相色谱-串联质谱同时快速测定水产品中氯霉素和红霉素的分析方法。样品通过乙腈提取,Oasis PRi ME HLB小柱一步法净化,采用高效液相色谱-串联质谱仪多反应监测扫描模式检测和同位素内标定量。检测水产品中的氯霉素和红霉素定量限分别为0.1μg/kg和0.5μg/kg。不同水产品(鱼、虾和蟹)在3个添加水平的平均回收率在86.7%~102.6%之间,相对标准偏差小于5%(n=6)。本方法简单易行、灵敏度较高,在日常检测方面存在一定优势。     

UPLC-MS-MS法检测辣椒及其制品和肉酱中的罗丹明B含量

建立了辣椒及其制品和肉酱中罗丹明B含量的超高效液相色谱-串联质谱联用检测方法。样品经乙腈提取后,经中性氧化铝固相萃取柱净化,超高效液相色谱-串联质谱法检测。本方法定量限0.1μg/kg,线性范围0.2~50 ng/mL;在罗丹明B添加水平0.1~10μg/kg时,辣椒片样品中的回收率76%~92%,辣椒制品中的回收率74%~93%,肉酱样品中的回收率70%~90%。     

Total content of As,Sb, Se,Te and Bi in Spanish vegetables,cereals and pulses and estimation of the contribution of these foods to the Mediterranean daily intake of trace elements

As, Sb, Se, Te and Bi were quantified in vegetables, pulses and cereals, in order to increase the available information on the presence of these elements in the Mediterranean daily intake. Samples were dry ashed and the ashes dissolved with diluted HCl. Hydride generation atomic fluorescence spectrometry was used for quantification. Limits of detection (LOD) ranged from 0.2 to 1.7 ng g⁻¹ and the accuracy was assessed by the analysis of three certified reference materials, Rice Flour (NIST 1568a), Tomato Leaves (NIST 1573) and Cabbage (IAEA 359). Good concordance between results found and certified values were always observed. As, Sb, Se, Te and Bi levels varied in samples analysed from values under the LOD till 1001, 47, 270, 104 and 48 ng g⁻¹, respectively.     

Determination of sodium,potassium, calcium,magnesium, zinc and iron in emulsified chocolate samples by flame atomic absorption spectrometry

In this study, oil-in-water formulations were optimized to determine sodium, potassium, calcium, magnesium, zinc, and iron in emulsified chocolate samples by flame atomic absorption spectrometry (FAAS). This method is simpler and requires fewer reagents when compared with other sample pre-treatment procedures and allows the calibration to be carried out using aqueous standards. Octyl stearate was used as oily phase. Tween 80 and Triton X100 were tested as surfactants. The optimum type and proportion of formulations were determined and their choice depended on the element studied. The emulsion preparation was performed by a conventional method that involves mixing both phases at 75 ± 5 °C by magnetic stirring and phase inversion to change the water-to-oil ratio by increasing the volume of the surfactant-water external phase and correspondingly decreasing the volume of internal phase. The validation of the method was performed against a baking chocolate standard reference material (SRM 2384) and recoveries ranged from 88.6% for K to 105.5% for Zn. The proposed method allowed the evaluation of the essential metal status of chocolate with minimum sample manipulation and was reproducible and economical.     

驼初乳中钾、钙、钠、镁、铜、铁、锌质量浓度的检测

为研究新疆双峰驼驼初乳中钾、钙、钠、镁、铜、铁、锌的质量浓度及其在泌乳期内的变化,采用火焰原子吸收分光光度法进行测定,回收率为92.45%～110.85%之间,相对标准偏差小于5%,说明该法具有良好的准确性和精密度。结果表明,新疆双峰驼驼初乳中钾的质量浓度最为丰富高,其次为钠、钙和镁;检测发现驼初乳中铜、铁、锌质量浓度未达到仪器最佳工作条件下的最低检出限。在泌乳期1~6 d内,钙元素和镁元素质量浓度的变化有相关性,差异显著;钠元素和钙元素质量浓度的变化与泌乳天数有相关性,差异显著;钙元素质量浓度的变化与泌乳天数有相关性,差异极显著。与牛乳相比,新疆双峰驼驼初乳中含有相对较高质量浓度的钾、钙、钠、镁的质量浓度较高,饮用驼初乳可作为补充人体所需钾、钙、钠、镁元素的一种有效途径。     

Prediction of fatty acid profiles in cow,ewe, and goat milk by mid-infrared spectrometry

Mid-infrared (MIR) spectrometry was used to estimate the fatty acid (FA) composition in cow, ewe, and goat milk. The objectives were to compare different statistical approaches with wavelength selection to predict the milk FA composition from MIR spectra, and to develop equations for FA in cow, goat, and ewe milk. In total, a set of 349 cow milk samples, 200 ewe milk samples, and 332 goat milk samples were both analyzed by MIR and by gas chromatography, the reference method. A broad FA variability was ensured by using milk from different breeds and feeding systems. The methods studied were partial least squares regression (PLS), first-derivative pretreatment + PLS, genetic algorithm + PLS, wavelets + PLS, least absolute shrinkage and selection operator method (LASSO), and elastic net. The best results were obtained with PLS, genetic algorithm + PLS and first derivative + PLS. The residual standard deviation and the coefficient of determination in external validation were used to characterize the equations and to retain the best for each FA in each species. In all cases, the predictions were of better quality for FA found at medium to high concentrations (i.e., for saturated FA and some monounsaturated FA with a coefficient of determination in external validation >0.90). The conversion of the FA expressed in grams per 100 mL of milk to grams per 100 g of FA was possible with a small loss of accuracy for some FA.     

ICP-MS测定饼干中的铅、砷、铬、镉、铜、锌、铁和锰

探讨了应用电感耦合等离子体质谱仪测定饼干中铅、砷、铬、镉、铜、锌、铁和锰8种重金属元素的方法。运用微波消解系统对样品进行消解,以铋、锗、钪和铟作为内标物,用ICP-MS对消解液进行检测,并采用国标方法对其结果进行验证。利用加标回收率试验和国家标准物质小麦(GBW 10052)检测试验考察了方法的准确性和可靠性。结果表明,该方法所测元素在标准溶液浓度范围内呈线性关系,相关系数均大于0.999,方法检出限在0.002~0.500 mg/kg之间,相对标准偏差均小于6.55%,本法与国标方法测量结果的相对偏差在3.73%~8.40%之间,加标回收率在88.0%~106%之间,标准物质的测定值与标准参考值符合要求。     

微波消解-MPT-AES法同时测定绿茶中锰、锌、铜、铁、铬、硒

绿茶样品经微波消解处理,用微波等离子体炬原子发射光谱法（MPT-AES）测定其中的锰、锌、铜、铁、铬和硒六种微量元素含量。详细考察了分析谱线、微波功率、载气流量、工作气流量、氧屏蔽气流量等实验参数,并分析了酸效应、易电离元素的干扰情况。采用正交实验方法研究了消解过程中微波压力、消解温度及消解时间三因素对消解结果的影响。在优化的实验条件下,测得锰、锌、铜、铁、铬和硒的检出限分别为8.2、46、18、28.8、4.4、4.5ng·mL-1,加标回收率在96.89%～102.32%之间,相对标准偏差（n=11）均小于3.25%。结果表明,MPT-AES是一种简便、快速、准确、无污染的绿色环保方法。     

AN INTRODUCTION TO MASS SPECTROMETRY AND ITS APPLICATION IN THE ANALYSIS OF BEER,WINE, WHISKY AND FOOD

Mass spectrometry is a powerful analytical technique by which different chemical compounds can be identified, and valuable information gained as to their chemical structure. Both qualitative and quantitative data can be obtained and the instrumentation can be used on a stand-alone basis, or as a detector for a chromatographic system such as gas chromatography or high performance liquid chromatography. This paper provides a basic knowledge for analysts and brewers alike not familiar with the technique. To illustrate its utility, a number of examples are given for the analysis of food, beverages and contaminant components in raw materials and product. These include the identification of phenolic flavour components in whisky and beer, fatty acids in pizza, diethylene glycol confirmation in wine and contaminants identified from beer packaging materials.     

液相色谱-串联质谱法检测饲料中洛美沙星、培氟沙星、氧氟沙星、诺氟沙星残留

目的建立一种可同时检测饲料中4种氟喹诺酮类药物残留的液相色谱-串联质谱(liquid chromatography-tandem mass spectrometry, LC-MS/MS)检测分析方法。方法试样用磷酸盐缓冲液和乙腈混合进行提取, MCX固相萃取柱净化,以甲醇-0.1%甲酸水溶液为流动相, LC-MS/MS法检测,同时定性、定量测定4种氟喹诺酮类抗生素残留。结果 4种氟喹诺酮类抗生素在HypersilGOLDC_(18)色谱柱上分离效果较好,添加的回收率在60.3%～91.0%之间,相对标准偏差在0.87%～5.91%之间(n=6),方法的检测限为2μg/kg,定量限为5μg/kg。结论该方法准确、简便、快速,能满足兽药残留分析的要求,适合测定饲料中4种氟喹诺酮类抗生素残留。     

快速消解-电感耦合等离子体质谱法测定水产配合饲料中的铬、铜、锌、砷、镉、汞和铅

目的 建立快速消解-电感耦合等离子体质谱法(ICP-MS)测定水产配合饲料中的铬(Cr)、铜(Cu)、锌(Zn)、砷(As)、镉(Cd)、汞(Hg)和铅(Pb)的检测方法。方法 用硝酸将样品在聚丙烯快速消解管中消解,通过优化碰撞池气体流量及在线添加内标的方式消除干扰,同时进行了线性、准确度及精密度试验,并应用于质控样品及实际样品的检测。结果 各元素的标准曲线线性良好,相关系数为1.0000,检出限为0.00229 ~ 0.15030 mg/kg,回收率为91.8% ~ 108.2%,相对标准偏差(RSD)为1.0% ~ 7.9%,质控样品测定值在标准值范围内。在市售水产配合饲料中发现2批次Cr含量超标,需对其来源及形态进行深入分析,评估潜在的质量安全及生态安全风险。结论 建立的方法高效准确,可应用于水产配合饲料的检测分析工作。     

火焰原子吸收分光光谱法测定玉米中铁、锰、铜、锌

采用HNO3-HClO4(4+1)湿法消解样品,用火焰原子吸收光谱法测定玉米中铁、锰、铜、锌的含量。测得铁、锰、铜、锌的回收率分别在97%～99%、95%～100%、95%～103%,100%～104%之间,平均回收率为95%～104%,RSD为0.1%～0.9%,表明该方法准确可靠。