超高效液相色谱法检测饮料中纳他霉素的含量

建立用超高效液相色谱测定饮料中纳他霉素含量的方法。用甲醇溶液提取样品中的纳他霉素,UPLC分析,外标法定量。采用BEHShieldRP18色谱柱,检测波长为303nm,以乙酸铵和乙腈为流动相,进行等度洗脱。该方法操作简单快捷,方法准确度和稳定性好。     

高效液相色谱法同时测定果蔬汁中脱氢乙酸与纳他霉素及其降解规律研究

目的建立高效液相色谱法(high performance liquid chromatography,HPLC)同时测定果蔬汁中的脱氢乙酸与纳他霉素。方法样品采用超声提取,以乙腈与0.1%甲酸-水溶液为流动相进行梯度洗脱,经过C_(18)色谱柱分离,采用二极管阵列检测器检测,检测波长为310 nm和305 nm,以外标法定量。结果脱氢乙酸与纳他霉素在0.01~20μg/m L浓度范围内线性关系良好(r~2=0.99987),定量限分别为1.0 mg/kg和0.5 mg/kg,均小于等于国标方法定量限。脱氢乙酸与纳他霉素分别在5、10和50 mg/kg及0.5、1和5 mg/kg 3个水平加标回收率分别为92.44%~95.02%和91.20%~103.49%,实验室内部变异系数分别为0.28%~0.43%和0.78%~10.44%。与国标方法对比,在置信度为95%时的显著性检验结果较好。研究脱氢乙酸和纳他霉素的降解规律发现,脱氢乙酸自身降解较慢,且受到样品基质影响较小;而纳他霉素自身降解较快,且受到样品基质影响较大。结论本方法准确可靠,精密度良好,可用于果蔬汁样品中脱氢乙酸与纳他霉素的同时测定。     

Development of high‐performance liquid chromatography and non‐aqueous capillary electrophoresis methods for the determination of fenoxycarb residues in wheat samples

BACKGROUND: Practical methods for the analysis of fenoxycarb residues in wheat samples were developed using high‐performance liquid chromatography (HPLC) and non‐aqueous capillary electrophoresis (NACE). RESULTS: Fenoxycarb residues in wheat were extracted with acetone by ultrasonication, followed by a clean‐up procedure with liquid–liquid extraction with 5% NaCl/dichloromethane. The HPLC was developed using C18 as column, MeOH/water (6:4, v/v) as the mobile phase and 199 nm as the detection wavelength. The optimal NACE condition was established with the running buffer of 20.0 mmol L^?1 NH₄Ac in 95% MeOH (pH* 9.0), and the applied voltage of 30 kV over a capillary of 50 µm i.d. × 48.5 cm × 40 cm effective length. Both methods gave the relatively lower limits of detection (0.008 mg kg^?1 for HPLC and 0.024 mg kg^?1 for NACE) and the higher recoveries (>85.0%). They were successfully applied to the determination of fenoxycarb in wheat samples. CONCLUSION: The results showed that the fenoxycarb residue gradually reduced to trace amounts after about 3 years, which implied that the pharmacological actions of fenoxycarb could last for about 3 years. Meanwhile, more effort should be made to control and reduce fenoxycarb residues because of its potential health risks to consumers. Copyright © 2007 Society of Chemical Industry     

Fast method to determine furosine in breakfast cereals by capillary zone electrophoresis

Furosine is a well-know marker of the extent of the thermal treatment applied to foodstuffs. A fast, reproducible and accurate capillary zone electrophoresis (CZE) method to analyse furosine focused on complex matrices, such as cocoa-added breakfast cereals, is presented. A representative group of 17 commercial cocoa-added breakfast cereals were determined by the reference method (HPLC) and by CZE. In addition, eight ready-to-eat breakfast cereals were tested to point out the application of the procedure to a simpler matrix. Data from both methodologies are compared by F-test and unpaired Student's t-test, showing no significant differences among them and an adequate correlation between methods was found (r ²=0.9852; p=0.000). The CZE method provides a valuable analytical tool for determination of furosine in cocoa-added breakfast cereals and is suitable for routine analysis where presence of highly retained material could limit the resolution and shelf-life of the analytical columns applied for HPLC. The analysis is carried out in 3 min. The stability of the migration time and the good correlation between HPLC–CZE results support the effectiveness of the method.     

Optimization analysis by capillary electrophoresis of thiamine in meat: comparison with high perfomance liquid chromatography

 A new capillary electrophoresis (CE) method for the analysis of thiamine in meat is proposed. Samples were submitted to acidic and enzymatic hydrolysis and the extracts were purified using ethanol and an ion exchange column. The thiamine content was determined by CE using 100 mM sodium tetraborate, 50 mM sodium phosphate (pH 7.6), 50 mM sodium dodecyl sulphate and 10% isopropyl alcohol as a separation buffer solution. The analysis was carried out at 15 kV and 50  °C in a 70 cm effective length× 75 μm i.d. fused-silica capillary using on-column UV detection at 254 nm and 7 s injection time (27 nl injection volume). The results obtained by CE for thiamine contents in meat were compared to those obtained by HPLC using an ion-pair reverse phase column with post-column derivatization and fluorescence detection. Received: 24 August 1998 / Revised version: 21 January 1999     

毛细管区带电泳-间接紫外测定食品中木糖醇

目的建立毛细管区带电泳间接紫外测定食品中木糖醇的新方法。方法样品用超纯水提取后离心,过0.45μm膜后上机进样。以未涂敷熔融石英毛细管(50μm×60.2 cm)为毛细管分离柱,以8 mmol/L 3,5-二硝基苯甲酸、10 mmol/L硼砂和0.5 mmol/L十六烷基三甲基溴化铵为分离缓冲溶液。分离电压为-20 k V,检测波长为200 nm,用外标法定量。结果方法检出限为3.00 mg/L(S/N=3),定量限为10.00 mg/L(S/N=9),线性范围为10.00~300.0 mg/L,线性相关系数r为0.9994。在20.00、40.00、80.00 mg/L添加水平下,平均回收率分别为103.2%、103.3%及104.8%,相对标准偏差分别为0.5%、1.2%及0.7%(n=3)。结论该方法简单快速,11 min内即可完成一次样品分析(清洗6 min、分离5 min),试剂及样品消耗量少,适用于食品中木糖醇的检测。     

Determination of melamine in milk powder,milk and fish feed by capillary electrophoresis: a good alternative to HPLC

BACKGROUND: Since September 2008, an increased incidence of kidney stones and renal failure in infants, associated with the ingestion of infant formula contaminated with melamine has been reported in China. Furthermore, melamine was not only found in many protein‐based food commodities, but also in the feeds for cattle and poultry. So it is necessary to develop a suitable method to determine melamine. RESULTS: A capillary zone electrophoresis (CZE) method for analysis of melamine was developed by use of running electrolyte containing 35 mmol L^?1 sodium dihydrogen phosphate at pH 3.5, with UV detection at 210 nm. Regression equation revealed linear relationships (r = 0.9999) between the peak‐area and the content of melamine from 0.8 to 80 µg mL^?1. The detection limit was 0.08 µg mL^?1. The method was successfully applied to the determination of melamine in milk powder, milk and fish feed, with the recoveries from 94.5% to 103.7%. CONCLUSION: The performance of the CZE method evaluated in terms of precision, limits of detection, accuracy and quantification were comparable and in good agreement with those obtained by the HPLC method, with the advantage of shorter analysis time and lower cost. Copyright © 2010 Society of Chemical Industry     

Study of hydroxycinnamic acids and malvidin 3-monoglucoside derivatives using capillary zone electrophoresis and ultra-performance liquid chromatography

Model solutions (pH = 3.5, 12% ethanol) of malvidin 3-O-glucoside (Mv3glc), the most common free anthocyanin in grapes and red wines from Vitis vinifera, and three free hydroxycinnamic acids present in wines (caffeic, ferulic and p-coumaric acids) were studied.     

Sorting for beef tenderness using high performance liquid chromatography and capillary electrophoresis: A research note

This study utilized two sampling methods to examine changes in sarcoplasmic proteins during aging of beef and their relation to tenderness. Water-soluble proteins either obtained by manually expressing exudates from the meat (drip) or by an extraction procedure using homogenization and centrifugation (ext) were analyzed for longissimus lumborum muscle using HPLC and capillary electrophoresis (CE) on days 2, 7, 10 and 14 postmortem. A peak that consistently increased with aging was identified using HPLC. Among nine peaks detected in the CE analysis, peak 9 (100kDa) that increased and peak 4 (30kDa) that decreased with aging were correlated (P<0.05) to tenderness as determined by Warner-Bratzler shear force (WBSF). For pooled data of all aging periods, drip sample explained the most variability (49%) in shear force compared to ext sample (25%) using HPLC analyses. At 2 days postmortem, a multiple linear regression model explained 83% of the variation in WBSF using CE-ext or HPLC-drip samples. Sixty percent of the variability in shear force was explained by CE-ext samples for day 7 data. The variability in shear force as explained by either drip or ext sample was less than 51 percent for 10 and 14 days postmortem data. The drip samples were comparable to ext samples in predicting WBSF values for both tough (>46N WBSF on day 2) and tender (<46N WBSF on day 2) strip loins using CE and HPLC procedure. Results suggest that a simple drip sampling may have a potential for use with either HPLC or CE analyses on day 2 postmortem for sorting carcasses into tenderness groups.     

超高效液相色谱-变波长法快速检测糕点中6种食品添加剂

摘 要：目的 建立一种快速的超高效液相色谱(ultra performance liquid chromatography,UPLC)-二极管阵列变波长检测方法,在10 min内同时测定糕点中安赛蜜、糖精钠、苯甲酸、山梨酸、脱氢乙酸和纳他霉素6种食品添加剂。方法 样品经20%甲醇水溶液(含2 mmol/L甲酸)提取,乙酸锌、亚铁氰化钾沉淀蛋白,以甲醇和20 mmol/L乙酸铵溶液(含2 mmol/L甲酸)作为流动相梯度洗脱,使用Agilent Poroshell 120 EC-C18 (4.6 mm×100 mm, 2.7 μm)色谱柱分离,二极管阵列-变波长检测。结果 6种食品添加剂在0.1~100 μg/mL范围内线性关系良好,相关系数均大于0.999,回收率为83.0%~110.2%,相对标准偏差(relative standard deviations, RSDs)为0.56%~5.96%。安赛蜜、糖精钠、苯甲酸、山梨酸、脱氢乙酸和纳他霉素的检出限为0.11~0.29 mg/kg,定量限为0.38~0.97 mg/kg。结论 该方法前处理简单,分析时间短,重现性好,适合用于糕点大批量检测。     

应用亲水作用液相色谱法测定食品中过氧化氢

目的 建立食品中过氧化氢含量的高压液相色谱检测方法。方法 用水提取样品中过氧化氢, 用乙腈做萃取液和流动相, 在1 mL/min流速下, 用Venusil HILIC 色谱柱(250 mm×4.6 mm, 5 μm, 100 ?)不经过衍生化, 直接通过紫外检测器检测食品中的过氧化氢。结果 过氧化氢的检出限为0.6 μg/mL, 定量限为2 μg/mL。对实际样品进行检测时, 平均回收率R≥30%, RSD≤7%。结论 该方法准确、灵敏、精密度高, 可用于食品中过氧化氢的测定。     

Profiling and quantifying quercetin glucosides in onion (Allium cepa L.) varieties using capillary zone electrophoresis and high performance liquid chromatography

There is increasing evidence that flavonols demonstrate beneficial properties for human health. Quercetin is the major flavonol present in onion (Allium cepa cv) and is present predominantly as quercetin 3,4′-diglucoside and quercetin 4′-monoglucoside. These compounds are known to be potent free radical scavengers and antioxidants, and are considered to be protective against cardiovascular disease. Analysis for the presence of these compounds has therefore become more important. Robust capillary zone electrophoresis and high performance liquid chromatography procedures were developed for profiling and quantifying the levels of quercetin 3,4′-diglucoside and quercetin 4′-monoglucoside in 70% methanol/water extracts of six different onion varieties available in Victoria, Australia. Quercetin 3,4′-diglucoside, which is not commercially available as a reference standard, was isolated from freeze-dried onion powder by preparative high performance liquid chromatography and used to quantify the levels in the onion extracts. Significant differences in the levels and ratios of the two compounds were seen between red, brown and white onion varieties (e.g. ‘Redwing’; quercetin 3,4′-diglucoside 191 mg/100 g DW, quercetin 4′-monoglucoside 85 mg/100 g DW; ‘Cream Gold’, quercetin 3,4′-diglucoside 153 mg/100 g DW, quercetin 4′-monoglucoside 58 mg/100 g DW, ‘Spanish white’; quercetin 3,4′-diglucoside <1 mg/100 g DW, quercetin 4′-monoglucoside <1 mg/100 g DW).     

Optimization and validation of a rapid method to determine citrate and inorganic phosphate in milk by capillary electrophoresis

Quantification of phosphate and citrate compounds is very important because their distribution between soluble and colloidal phases of milk and their interactions with milk proteins influence the stability and some functional properties of dairy products. The aim of this work was to optimize and validate a capillary electrophoresis method for the rapid determination of these compounds in milk. Various parameters affecting analysis have been optimized, including type, composition, and pH of the electrolyte, and sample extraction. Ethanol, acetonitrile, sulfuric acid, water at 50 degrees C or at room temperature were tested as sample buffers (SB). Water at room temperature yielded the best overall results and was chosen for further validation. The extraction time was checked and could be shortened to less than 1 min. Also, sample preparation was simplified to pipet 12 microl of milk into 1 ml of water containing 20 ppm of tartaric acid as an internal standard. The linearity of the method was excellent (R2 > 0.999) with CV values of response factors <3%. The detection limits for phosphate and citrate were 5.1 and 2.4 nM, respectively. The accuracy of the method was calculated for each compound (103.2 and 100.3%). In addition, citrate and phosphate content of several commercial milk samples were analyzed by this method, and the results deviated less than 5% from values obtained when analyzing the samples by official methods. To study the versatility of the technique, other dairy productssuch as cream cheese, yogurt, or Cheddar cheese were analyzed and accuracy was similar to milk in all products tested. The procedure is rapid and offers a very fast and simple sample preparation. Once the sample has arrived at the laboratory, less than 5 min (including handling, preparation, running, integration, and quantification) are necessary to determine the concentration of citric acid and inorganic phosphate. Because of the speed and accuracy of this method, it is promising as an analytical quantitative testing technique.     

高效液相色谱法检测酸奶中的唾液酸

建立了高效液相色谱-荧光检测器(HPLC-FLD)测定酸奶中唾液酸含量的分析方法。该方法为:使用1moL/L甲酸80℃下水解样品2h,以4,5-亚甲二氧基-1,2-邻苯二铵盐(DMB)为衍生化试剂,在80℃下衍生50min后,利用Zorbax SB-Aq色谱柱对衍生化产物进行分离,荧光检测器检测,外标法定量。该方法唾液酸检出限为0.2mg/L,线性范围0.5~10mg/L之间,线性良好,相关系数为0.9998,加标样品的回收率为88.41%~112.08%之间,相对标准偏差(n=6)为4.73%~10.01%之间。说明该方法检测结果准确,满足检测需求,可用于不同奶制品中唾液酸检测。     

毛细管电泳-聚类分析方法在醋分类中的应用

利用醋溶液的毛细管电泳提供醋的内在成分信息,采用SPSS主成分分析法对醋的有机组分进行主成分分析,选出5个特征组分。在此基础上聚类分析成功的将山西和镇江醋分为两类,结果与实际基本符合,表明醋的有机组分的分布特征与醋的区域品种关系显著。这为醋的类别鉴定和醋的近缘性研究提供了依据。     

高效液相色谱法测定果汁、果酱中的皂黄

目的建立高效液相色谱法检测果汁、果酱中皂黄含量的分析方法。方法试样经20%(V:V)甲醇溶液超声提取,离心取上清液,高效液相色谱—二极管阵列检测器分析。结果皂黄在0.50～100μg/mL浓度范围内呈现良好的线性关系(r~20.9999),具有较高的分离度且峰型对称,果汁和果酱的标准物质加入实验的回收率分别在96.1%～101.9%和79.2%～99.4%之间,相对标准偏差(relative standard deviation,RSD)分别为1.1%～2.3%和4.3%～7.4%。结论该方法具有操作简便、准确度高、灵敏度高和稳定性好等优点,适用于果汁、果酱中皂黄含量的测定。     

高效液相色谱法检测食品中黄曲霉毒素研究进展

该文介绍近年高效液相色谱法检测食品黄曲霉毒素最新进展,尤其是各种净化手段在分析中应用,电喷雾离子化三重四级杆串联质谱应用使提取和净化步骤简化,检测时无需衍生化,表现出比荧光检测法更大优势。     

高效液相色谱法测定保健食品中水飞蓟素的含量

目的建立高效液相色谱法(high performance liquid chromatography,HPLC)测定保健食品中水飞蓟素的含量。方法样品以甲醇为提取剂超声提取30 min,以甲醇-水(55:45,V:V)为流动相,流速为0.8 mL/min,采用色谱柱Agilent TC-C_(18)分离,在288 nm检测波长下经HPLC检测;同时对检测波长、流动相比例、提取剂和提取时间等条件进行优化。结果水飞蓟素浓度在8.152~203.8μg/mL范围内呈良好的线性关系,相关系数为0.9999,平均回收率为100.35%,RSD值为0.95%,方法检出限为11.6 ng/g。结论该方法快速准确,可适用于保健食品中水飞蓟素含量的测定。     

高效液相色谱法测定保健食品中番茄红素的含量

目的建立保健食品中番茄红素高效液相色谱法(high performance liquid chromatography,HPLC)含量测定方法。方法色谱柱为Grace Apollo C_(18)柱(250 mm×4.6mm,5μm),以甲醇-乙酸乙酯(95:5,V:V)为流动相等度洗脱,柱温30℃,流速1mL/min,检测波长472 nm。结果番茄红素在1.01～50.45μg/m L浓度范围内线性关系良好(r~2=0.9997),高、中、低3个浓度水平下的加样回收率为96.20%～105.60%,相对标准偏差(relative standard deviation,RSD)值不大于2.50%。采用该方法对市售7个厂家的产品进行测定,发现不同厂家产品中番茄红素的含量相差很大,其中3个厂家的含量低于其标示量,质量问题值得引起关注。结论本文建立的方法简单、准确,同时精密度、重复性良好,是对现有国家标准方法 GB/T 22249-2008的有效改进,可用于番茄红素保健食品的质量控制。     

高效液相色谱法测定保健食品中磷脂酰丝氨酸含量

摘 要: 目的 建立高效液相色谱法测定磷脂酰丝氨酸。方法 样品经过正己烷：异丙醇（25：75, V:V）溶解, 以正己烷：异丙醇：1%磷酸水溶液=（25:70:5, V:V:V）为流动相, 等度洗脱, 经SIL 色谱柱（4.6 mm×250 mm,5 μm）分离, 并于205 nm波长检测。结果 磷脂酰丝氨酸在浓度0.13504~0.67520 mg/mL之间呈现良好的线性关系, r=0.9993, 平均回收率为96.16%~99.60%, 相对标准偏差为1.1%。结论 该方法测定保健食品中磷脂酰丝氨酸含量具专属性强, 耗时短、操作简便、准确、重现性好,可在实验室推广。