毛细管电泳涂层研究及食品检测中的应用

毛细管电泳涂层技术因为分离碱性蛋白的需求而诞生,研究者致力于采用不同的材料和方法提高毛细管电泳的分离性能。目前,对毛细管内壁进行涂层改性依然是提高毛细管电泳的分离效果和重现性,抑制分析物与毛细管内壁间吸附作用的最有效、最常用的方法。随着毛细管电泳(CE)与质谱(MS),激光诱导荧光检测(LIF)等联用技术的发展,毛细管电泳涂层在生命科学技术、生物医药工程、环境卫生保护、食品质量检测等领域的广泛应用。本文根据涂层材料的种类和制备机理,对近年来毛细管电泳涂层技术的特点、发展和在食品检测领域的应用状况进行了综述。     

高效毛细管电泳法快速测定乳制品中三聚氰胺

建立高效毛细管电泳快速测定乳制品中三聚氰胺含量的方法。样品用100mmol/L 醋酸提取,以150mmol/L磷酸二氢钠为分离缓冲液,以未涂敷石英毛细管(20cm(有效长度)× 50μm)为分离柱,于235nm 波长处检测,采用峰面积外标法定量。实验研究缓冲溶液的浓度、分离溶液pH 值及样品前处理条件对三聚氰胺准确定量的影响。方法检出限为0.06mg/L,定量限为0.2mg/L,线性范围为0.2～200mg/L,线性相关系数r=0.9998。1.0、10mg/L 添加水平的平均加标回收率分别为93.0% 及84.3%。该方法简单快速,6min 之内即可完成一次样品分析(预清洗2min,分离4min)且试剂消耗少、环境友好及检测准确,适合于各类乳制品中三聚氰胺的常规测定。     

高效毛细管电泳法快速测定乳铁蛋白原料的纯度北大核心CSCD

建立了动态涂层毛细管电泳快速检测乳铁蛋白含量的方法。并运用该方法对不同乳铁蛋白原料的纯度进行了检测。经检测4种乳铁蛋白原料的纯度分别为乳铁蛋白A91.05%,乳铁蛋白B93.62%,乳铁蛋白C94.38%,乳铁蛋白D75.81%;相对标准偏差(RSD)分别为1.0%,0.8%,1.2%,0.9%。并与供应商所提供的原料纯度进行比较,讨论了造成二者之间略微差异的原因。结果表明,该动态涂层方法能够有效抑制毛细管内壁对乳铁蛋白的吸附,对于乳铁蛋白的检测及纯度的验证十分有效,为此类蛋白的检测提供了一种手段。     

毛细管电泳安培检测法快速测定巧克力中的香兰素

运用毛细管电泳安培检测法研究了巧克力中香兰素的快速测定方法,研究了电极电位、缓冲液的浓度和pH、分离电压以及进样时间等因素对分离测定的影响。在30mmol/L的硼砂（pH9.24）运行缓冲液中,施加15kV的分离电压及+0.65V（vs.SCE）的电极电位条件下,铜电极对香兰素有很好的响应。香兰素在5.0×10-6～1.0×10-3g/mL范围内存在较好的线形关系,检测限为3.87×10-7g/mL（S/N=3）。对实际样品的测定,回收率为96.5%～102.8%,结果令人满意。      

毛细管电泳法直接分离测定果冻中的色素

建立毛细管电泳法直接测定果冻中亮蓝、胭脂红、柠檬黄的方法,研究缓冲溶液种类、浓度、pH值、电压等对分离的影响,并对分离条件进行优化。在波长255nm、分离电压18kV、pH8.5、5mmol/L Na2HPO4-5mmol/L Na2B4O7溶液中,亮蓝、胭脂红、柠檬黄在6min内得到了较好的分离。用于部分市售果冻样品的测定,得到较满意结果,回收率为85%～110%。     

毛细管电泳-电化学发光法分离检测鱿鱼丝中的组胺

建立一种以三联吡啶钌为电化学发光体系的毛细管电泳-电化学发光检测系统,并将其应用于分离检测鱿鱼丝中的组胺。重点考察检测池中条件（检测电位,吡啶钌浓度和检测池中缓冲溶液pH值）、进样参数（进样高压和进样时间）及分离参数（分离高压,运行缓冲溶液pH值和浓度）等因素对组胺分离及发光强度的影响。结果表明:在检测电位1.15V,Ru（bpy）3²⁺浓度5mmol/L（pH7.0）,进样时间8s,进样高压10kV,运行高压18kV,运行缓冲溶液pH3.40,50mmol/L磷酸盐缓冲溶液条件下,体系的电化学发光强度与二盐酸组胺的浓度呈良好的线性关系,其线性方程为I=1.42c+30.83,相关系数r=0.9981（n=6）,检出限（S/N=3）0.468μmol/L。采用该方法测定鱿鱼丝中的组胺,其峰高和迁移时间的相对标准偏差（RSD）值分别为0.43%和0.29%,加标回收率100.32%～106.55%。该方法具有分析速度快,分离效果好,灵敏度高,重现性好等特点,适用于水产品及其制品中组胺的快速检测。     

高效毛细管电泳法快速测定碱金属及碱土金属离子

应用高效毛细管区带电泳法快速测定饮料中的6种碱金属及碱土金属离子。采用75μm×57cm（有效长度50cm）的未经处理的熔融石英毛细管柱，以5mmol／L，咪唑溶液作为背景电解质（用0．1mol／LH2SO4溶液调PH值至4．5），选用25KV分离电压和22℃柱温，于210nm波长处以间接紫外进行检测，对样品中的K+、Na+、Li+、Ca2+、Mg2+、Ba2+等6种碱金属及碱土金属离子进行分离测定。实验结果表明：应用毛细管区带电泳（CZE）法测定饮用水及饮料中碱金属和碱土金属离子具有快速、简便、灵敏度高、重现性好以及成本低等优点。测定结果与原子吸收光谱法（AAS法）无显著性差异。     

亲和毛细管电泳研究

该文对近几年新发展的亲和毛细管电泳(ACE)优点、原理进行简要介绍,且介绍ACE在分子生物学、生物化学应用及其在亲和常数测定、竞争免疫分析、药物先导化合物筛选、核酸片段识别等方面应用。     

毛细管电泳在食品安全检测中的应用进展

“民以食为天,食以安为先。”作为一个全球性问题,食品安全不仅影响每个人的健康水平与生活质量,更关乎整个国家的经济与发展。近年来,“毒奶粉”、“地沟油”、“染色馒头”、“毒豆芽”等频繁发作的食品安全恶性事件引起了社会的极大关注,也使人们对食品安全检测的需求进一步提高。而食物种类多样、成分复杂、及加工工艺繁琐等特点也为食品安全检测技术和方法带来了更大的难度和挑战。众多检测方式中,毛细管电泳（CE）以分析成本低、样品用量少、分离模式灵活多样、对环境污染小等优势被广泛应用。本文综述了2015年以来CE在食品安全检测中农药残留、兽药残留、多种食品添加剂、食品包装材料中双酚A和塑化剂等多个方面的分析应用,并对其未来的发展方向作了简要的展望。     

3种毛细管电泳方法分析牛乳蛋白的比较

对比毛细管凝胶电泳(CGE)、毛细管未涂层管区带电泳(CZE)和涂层管区带电泳(CZE)在牛乳蛋白分离和定量分析,结果表明在分离条件、分离效果和定量特征上,毛细管涂层区带电泳优于其他两种电泳。应用涂层毛细管区带电泳对不同阶段婴幼儿配方乳粉的蛋白组成进行测定,分离效果较好。     

Rapid determination of gizzerosine in fish meals using microchip capillary electrophoresis with laser-induced fluorescence detection

ABSTRACT

Sensitive detection of gizzerosine, a causative agent for deadly gizzard erosion in chicken feeds, is very important to the poultry industry. In this work, a new method was developed based on microchip capillary electrophoresis (MCE) with laser-induced fluorescence (LIF) detection for rapid analysis of gizzerosine, a biogenic amine in fish meals. The MCE separation was performed on a glass microchip using sodium dodecyl sulfate (SDS) as dynamic coating modifier. Separation conditions, including running buffer pH and concentration, SDS concentration, and the separation voltage were investigated to achieve fast and sensitive quantification of gizzerosine. The assay proposed was very quick and could be completed within 65 s. A linear calibration curve was obtained in the range from 0.04 to 1.8 μg ml^–1 gizzerosine. The detection limit was 0.025 μg ml^–1 (0.025 mg kg^–1), which was far more sensitive than those previously reported. Gizzerosine was well separated from other endogenous components in fish meal samples. Recovery of gizzerosine from this sample matrix (n = 3) was determined to be 97.2–102.8%. The results from analysing fish meal samples indicated that the present MCE-LIF method might hold the potential for rapid detection of gizzerosine in poultry feeds.     

Rapid determination of sodium in milk and milk products by capillary zone electrophoresis

A capillary zone electrophoresis method for the determination of Na in milk and milk products was developed and compared with an International Organization for Standardization/International Dairy Federation standard method that is based on flame atomic absorption spectrometry. The adoption of a background electrolyte consisting of 10 mM imidazole adjusted to pH 3.75 by the addition of oxalic acid allowed baseline separation of Na from other milk cations and from Li ion, which was adopted as an internal standard. Method validation was performed and the results for linearity, precision, limit of detection, limit of quantification, and recovery are presented. The procedure was tested on commercial milk samples differing in fat content (whole, semiskimmed, and skimmed) and processing conditions (pasteurization, UHT sterilization, and microfiltration). The reliability of the method was confirmed for different varieties of cheese and other milk products. The method enables the routine measurement of Na content by a rapid and accurate capillary zone electrophoresis procedure.     

毛细管电泳电化学发光法快速分离检测水果中的精胺

目的:建立水果中精胺含量测定的毛细管电泳电化学发光(CE-ECL)法。方法:利用CE-ECL技术建立了一种高效快速准确的测定水果中精胺含量的的方法。结果:精胺标准溶液在2×10^-4~3×10^-1 mmol/L浓度范围内与ECL强度呈良好的线性关系,其线性方程为I=1114.2c+99.41,相关系数r=0.9996(n=5),检出限(S/N=3)为9.9×10^-5 mmol/L,加标回收率分别为95.1%~101.2%、99.0%~100.8%和100.6%~106.0%。结论:该方法简单、准确,重复性好,可用于研究果蔬采后保鲜贮藏和延长货架期。     

Sample preparation for photometric determination of histamine in foodstuffs compared with capillary electrophoresis

 To determine levels of histamine, two methods were used, photometry in conjunction with two sample clean-up procedures, and capillary zone electrophoresis (CZE). The two sample clean-up procedures used were liquid liquid extraction (LLE) with n-butanol and solid phase extraction (SPE). Using CZE, the separation of histamine from the matrix was good. The other method, photometry, represents a classic and simple method, that can be employed for in situ measurement of histamine. We found that it was necessary to clean up the samples prior to photometry; if this was not done, the recorded levels of histamine were higher than those determined by CZE. In order to determine levels of histamine, both of these rapid tests were applied to ten different foodstuffs. The levels of histamine measured using photometry following either LLE or SPE were compared. The results indicated that photometry is a suitable method for the measurement of histamine, although the sample solutions have to be purified by either LLE or SPE. Samples do not need to be cleaned up before CZE because there is no interference between histamine and attendant material. Both sample clean-up procedures were applied to the following foodstuffs: tomatoes, sauerkraut, tuna, leaf spinach, cream spinach, white wine and mackerel. The differences of the measured values vary between 3% and 18% for LLE and 6% and 27% for SPE. For the other foodstuffs, such as beef, beer and non-alcoholic beer, only one sample clean-up procedure is suitable. LLE used for beef and beer leads to differences in measured levels of histamine between 18% and 50%, respectively, whereas SPE used for non-alcoholic beer leads to differences of 20%. Received: 3 September 1997 / Revised version: 23 October 1997     

Sample preparation for photometric determination of histamine in foodstuffs compared with capillary electrophoresis

 To determine levels of histamine, two methods were used, photometry in conjunction with two sample clean-up procedures, and capillary zone electrophoresis (CZE). The two sample clean-up procedures used were liquid liquid extraction (LLE) with n-butanol and solid phase extraction (SPE). Using CZE, the separation of histamine from the matrix was good. The other method, photometry, represents a classic and simple method, that can be employed for in situ measurement of histamine. We found that it was necessary to clean up the samples prior to photometry; if this was not done, the recorded levels of histamine were higher than those determined by CZE. In order to determine levels of histamine, both of these rapid tests were applied to ten different foodstuffs. The levels of histamine measured using photometry following either LLE or SPE were compared. The results indicated that photometry is a suitable method for the measurement of histamine, although the sample solutions have to be purified by either LLE or SPE. Samples do not need to be cleaned up before CZE because there is no interference between histamine and attendant material. Both sample clean-up procedures were applied to the following foodstuffs: tomatoes, sauerkraut, tuna, leaf spinach, cream spinach, white wine and mackerel. The differences of the measured values vary between 3% and 18% for LLE and 6% and 27% for SPE. For the other foodstuffs, such as beef, beer and non-alcoholic beer, only one sample clean-up procedure is suitable. LLE used for beef and beer leads to differences in measured levels of histamine between 18% and 50%, respectively, whereas SPE used for non-alcoholic beer leads to differences of 20%. Received: 3 September 1997 / Revised version: 23 October 1997     

Electrochemical biosensor based on gold coated iron nanoparticles/chitosan composite bound xanthine oxidase for detection of xanthine in fish meat

A xanthine oxidase was immobilized covalently onto chitosan bound gold coated iron nanoparticles (CHIT/Fe-NPs@Au) electrodeposited on the surface of pencil graphite electrode (PGE). A xanthine biosensor was fabricated using XOD/CHIT/Fe-NPs@Au/PGE as working, Ag/AgCl as reference and Pt as auxiliary electrode connected through potentiostat. The enzyme electrode was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and electrochemical impedance spectroscopy (EIS). The biosensor exhibited optimum current response within 3 s at pH 7.4, 35 °C and working range 0.1–300 μM, when polarized at 0.5 V vs Ag/AgCl. The sensitivity of the biosensor was 0.001169 mAμ M^–1 cm^–2 with detection limit of 0.1 μM (S/N = 3). The biosensor showed only 25% loss in its initial activity after its 100 uses over 100 days, when stored at 4 °C.     

基于静电作用诱导金铂纳米粒子聚集的比色方法检测鱼肉中组胺

目的 基于金铂纳米粒子(AuPt nanoparticles, AuPt NPs)建立一种简便、灵敏的比色方法检测鱼肉中的组胺。方法 由柠檬酸钠制备的AuPt NPs表面带负电,组胺通过静电作用能与AuPt NPs相结合,诱导AuPt NPs聚集,溶液由棕红色变为灰色;同时引起AuPt NPs表面等离子体共振发生红移,吸收峰由510 nm移至650 nm附近,将650 nm和510 nm的吸光度比值(A650/A510)作为检测组胺的参数。结果 在最优的条件下(反应时间为1 h、反应温度为25℃),A650/A510随着组胺浓度的升高而升高,A650/A510与0.5-30 μmol/L的组胺浓度呈现良好的线性关系,线性方程为A650/A510=0.019C组胺+0.3686(r2=0.9962),方法检出限为0.32 μmol/L。将方法用于鱼肉样品的检测,加标回收率为102.1%-111.7%,相对标准偏差为1.8%-3.1%。结论 本实验方法具有简便、快捷和成本低的优点,可实现鱼肉中组胺的可视化快速检测。     

Rapid simultaneous determination of organic acids,free amino acids,and lactose in cheese by capillary electrophoresis

A capillary electrophoresis (CE) method for the simultaneous separation of 11 metabolically important organic acids (oxalic, formic, citric, succinic, orotic, uric, acetic, pyruvic, propionic, lactic, and butyric), 10 amino acids (Asp, Glu, Tyr, Gly, Ala, Ser, Leu, Phe, Lys, and Trp), and lactose has been optimized, validated, and tested in dairy products. Repeatability and linearity were calculated for each compound, with detection limit values as low as 0.2 x 10(-2) mM for citric acid and Gly. The method was applied to analyze yogurt and different varieties of commercial cheeses. This method yielded specific CE patterns for different varieties of cheese. Also, it has been shown to be sensitive enough to measure small changes in composition of some of those compounds in fresh cheese stored under accelerated ripening conditions for 2 d at 32 degrees C (e.g., from 1728.3 +/- 45.0 to 1166.7 +/- 4.5 mg/100 g of DM in the case of lactose, or from 23.5 +/- 0.6 to 76.8 +/- 16.7 mg/100 g of DM in the case of acetic acid).     

Determination of histamine by capillary zone electrophoresis using a low-pH phosphate buffer: application in the analysis of fish and marine products

 Histamine levels in samples of fish and marine products were determined by capillary zone electrophoresis using phosphate buffer at pH 2.44 and UV detection at 214 nm. A plot of the area of the peaks versus histamine concentration was linear over the range of 1–100 ppm with a correlation coefficient of 0.9996. Calibration using the height of the peak also gave good correlation, with a correlation coefficient of 0.9969, at concentrations between 1 ppm and 20 ppm. The recovery of added histamine in different samples of fish and fish products was, on average, 99.65%. The method described in this work was used for the quantitation of histamine in fish and fish products. Received: 19 March 1996/Revised version: 22 July 1996     

Simultaneous determination of ammonia,dimethylamine, trimethylamine and trimethylamine-n-oxide in fish extracts by capillary electrophoresis with indirect UV-detection

A capillary electrophoretic method with indirect UV detection is described for simultaneous determination of ammonia, dimethylamine (DMA), trimethylamine (TMA) and trimethylamine-n-oxide (TMAO) in aqueous extracts of fish. A buffer consisting of 4 mM formic acid, 5 mM copper(II)sulfate and 3 mM crown ether 18-crown-6 enabled separation of the analytes in 5–10 min. The use of an extended light path capillary technique resulted in a good sensitivity and repeatability. The linear dynamic range, based on a hydrostatic injection at 50 mbar for 2 s, was from the detection limit to at least 2.5 mM. The detection limit for ammonia, DMA, TMA, and TMAO was less than 0.04 mM, corresponding to 2 mg nitrogen per 100 g fish. As an extra benefit, the method also provided a quantitative determination of potassium, sodium, calcium and magnesium ions.