Determination of sucralose in foods by HPLC using pre-column derivatization

The development of a sensitive pre-column derivatization high-performance liquid chromatography (HPLC) method for determination of sucralose is reported. Sucralose is converted into a strongly ultraviolet (UV)-absorbing derivative, possessing strong absorption at 260 nm, by treatment with p-nitrobenzoyl chloride (PNBCl). Homogenized samples were dialyzed and washed with a Bond Elut ENV cartridge, then the eluate was evaporated to dryness and the residue was derivatized. Subsequently, the sucralose derivative was purified with hexane-ethyl actate (9:1) in a silica cartridge, and then the sucralose derivative was eluted with acetone. HPLC was performed on a phenyl column, using acetonitrile-water (73:27) as a mobile phase with UV detection (260 nm). The calibration curve was linear in the range of 1 microgram/mL to 50 micrograms/mL of sucralose. The recoveries of sucralose from eight kinds of foods spiked at the levels of 0.20 and 0.05 g/kg of sucralose were more than 76.2% with SD values in the range from 0.90% to 4.31%. The quantitative limit of the developed method was 0.005 g/kg for sucralose in samples.     

Determination of sucralose in foods by anion-exchange chromatography and reverse-phase chromatography

Simple and rapid methods for the determination of sucralose in foods were developed using anion-exchange chromatography (AEC) with pulsed amperometric detection and reverse-phase HPLC with refractive index detection. Sucralose was extracted with water or methanol, and the extracted solution was cleaned up on a Sep-Pak C18 cartridge and a Sep-Pak Alumina N cartridge. The AEC separation was performed on a CarboPac PA1 column (4.0 mm i.d x 250 mm) using 100 mmol/L sodium hydroxide-50 mmol/L sodium acetate solution as the mobile phase at a flow rate of 1.0 mL/min. The recoveries of sucralose from foods were 80.6-102.0%, and quantitation limits from foods except chewing gum were 0.5 microgram/g (2 micrograms/g from chewing gum). The reverse-phase HPLC separation was performed on an Inertsil ODS-3V column (4.6 mm i.d x 150 mm) using methanol-water (25:75) as the mobile phase at a flow rate of 1.0 mL/min. The recoveries of sucralose from foods were 80.2-121.2%, and quantitation limits from foods except chewing gum were 5 micrograms/g (20 micrograms/g from chewing gum).     

Determination of sucralose in foods by liquid chromatography/tandem mass spectrometry

A simple method for the determination of sucralose in various foods using liquid chromatography-electrospray ionization tandem mass spectrometry (LC/MS/MS) was developed. Sucralose was extracted with water or methanol, and the extract was cleaned up on a C18 cartridge, and diluted with water for injection into the LC/MS/MS. The LC separation was performed with a reversed-phase gradient on an ODS column, and the mass spectral acquisition was done in the negative ion mode by applying selected reaction monitoring (SRM). The recoveries of sucralose from various kinds of foods fortified at 100 micrograms/g and 5 micrograms/g were 88.1-96.7% and 92.7-98.5%, respectively. The lower limits of quantification were 0.5 microgram/g in beverage, low-malt beer, yogurt and chocolate and 2.5 micrograms/g in other foods. Forty-three commercial foods containing sucralose were analyzed by this method. Sucralose was detected in all samples at levels of 3.8-481 micrograms/g.     

高效毛细管区带电泳-间接紫外法测定食品中三氯蔗糖

目的建立利用毛细管区带电泳-间接紫外法测定食品中三氯蔗糖的方法。方法样品用超纯水提取,离心所得的上清液直接进样,以未涂层熔融石英毛细管(50μm×60.2 cm)为分离柱,3 mmol/L 3,5-二硝基苯甲酸+10 mmol/L磷酸钠+12 mmol/L氢氧化钠(p H=12.58)+0.5 mmol/L十六烷基三甲基溴化铵为分离缓冲液;检测波长200 nm,分离电压-20 k V。采用校正峰面积外标法进行定量。结果方法检出限为10 mg/L,定量限为30 mg/L,线性范围为30~300 mg/L,线性相关系数r=0.999 1。低、中、高3个质量浓度(40、60及80 mg/L)的加标回收率分别为108.1%、102.6%、103.5%,相对标准偏差(RSD)分别为1.3%、1.3%及1.0%,方法精密度为2.0%。结论本研究样品前处理操作简单,20 min之内即可完成三氯蔗糖的含量分析(预清洗6 min,分离13 min),实现了与其结构相似但又同时存在于食品中蔗糖的分离,且试剂及样品消耗量少,适用于实验室对于食品中三氯蔗糖的检测。     

Determination of benzimidazole anthelmintics in livestock foods by HPLC

A simple and rapid liquid chromatographic method was developed for the simultaneous determination of twelve benzimidazole anthelmintics in livestock foods using reversed-phase high-performance liquid chromatography with photodiode array detection (PDA). A sample was homogenized with acetonitrile and n-hexane, and centrifuged. The acetonitrile phase was isolated and evaporated. The residue was dissolved in 0.1 mol/L carbonate buffer solution (pH = 9.1), sonicated, and then subjected to clean-up on a Bond Elut LRC-C18 cartridge. The benzimidazole compounds were separated isocratically on a Capcell Pak C18 UG 120 (5 microns, 150 x 4.6 mm i.d.) column and detected by PDA at 295 and 313 nm. Mixtures of acetonitrile and 0.05 mol/L ammonium acetate in mixing ratios of (20:80) and (40:60) were used as the mobile phase, and the flow-rate was 1.0 mL/min at 40 degrees C. The mean recoveries (n = 3) from 0.1-0.5 microgram/g added samples were 72.6-97.2% with coefficients of variation of 0.3-8.5%. The detection limits were 0.01-0.05 microgram/g.     

LC-MS法测定饮料中的三氯蔗糖

建立了测定饮料中三氯蔗糖的液质联用(LC-MS)检测方法.样品经亚铁氰化钾溶液和乙酸锌溶液去除蛋白等杂质后,用乙腈和水溶液为流动相进行梯度洗脱,在Waters Atlantis C18色谱柱(150mm ×2.1mm,5μm)分离后,用电喷雾负离子模式电离,采用多反应监测(MRM)模式检测,以m/z 395>359作为定量离子对进行定量.实验结果表明,三氯蔗糖在0.1～1.0μg/mL范围内呈良好的线性关系,相关系数为r=0.999,三氯蔗糖的方法检出限为0.001mg/kg.3个添加水平的回收率为82.3%～100.5%,相对标准偏差(RSD)均小于12.7%.本方法快速简便,操作稳定,可适用于饮料中三氯蔗糖的质量控制检测.     

Determination of curcuminoid colouring principles in commercial foods by HPLC

The present study deals with determination of curcuminoids, which are potential sources of a natural food colourant, present in commercially available food items in Korean markets. Three principles, curcumin (1), demethoxycurcumin (2), and bisdemethoxycurcumin (3), were isolated from Curcuma longa roots. Moreover, their contents were investigated in 54 items of 16 food types by HPLC-DAD at 420 nm. The recovery rates showed remarkable differences, and ham of solid state exhibited the highest rate (98.9%), while beverage of liquid state was the lowest (0.34%). Among food items, curcumin (1) detected the predominant content and curry showed the highest curcuminoid in the range of 37.24–617.98 μg/g. Interestingly, curry powder was the highest content, followed by compressed curry, and retorted curry. The remaining food items, only mustard, candy, and pickle exhibited curcuminoids. This study provides that analysis of curcuminoids may be a potential tool for the quality control of manufactured foods.     

HPLC法测定食品中非食用色素酸性橙Ⅱ

为保证食品安全，建立了一套检测食品中非食用色素酸性橙Ⅱ的方法。以甲醇＋0．02mol／L醋酸铵水溶液为流动相，梯度洗脱，在484nm用紫外检测器检测，其重复测定结果的相对标准偏差为5．91％，回收率在91．75％-103．24％范围内，本方法适用于食品中合成色素与非食用色素酸性橙Ⅱ的同时测定。     

Determination of acrylamide in processed foods by column-switching HPLC with UV detection

A simple and convenient analytical method for the determination of acrylamide in processed foods was established. Acrylamide was extracted with water in an ultrasonic bath. The extract was passed through an OASIS HLB cartridge and the eluate was injected into the HPLC system using a column-switching technique. The HPLC system consisted of two pumps, two 6-port-2-position valves, two columns and a UV detector. At first, the sample solution was chromatographed on an ODS column with a mobile phase of water, then the flow of the mobile phase was switched using a 6-port-2-position valve, and the acrylamide peak fraction was introduced into an aqueous gel permeation column (analytical column). The fraction was chromatographed again on the analytical column with a mobile phase of water, and the eluate was monitored with a UV detector (205 nm). The recoveries of acrylamide from potato chips, fried potato, croquette and instant noodle fortified at levels of 50 to 1,000 micrograms/kg were 93.1 to 101.5% and the coefficient of variation was 1.5 to 5.2%. The detection limit corresponded to 10 micrograms/kg in processed foods. Forty-six samples, potato chips (11), fried potato (10), croquette (20) and instant noodle (5), were analyzed by this method. The acrylamide level was 67-4,499 micrograms/kg for potato chips, 125-1,183 micrograms/kg for fried potato, nd-255 micrograms/kg for croquette and nd-151 micrograms/kg for instant noodle.     

固相萃取-高效液相色谱法测定保健食品中维生素B12的研究

为监管保健食品中维生素的含量 ,建立了保健食品中维生素B12 的化学分析法 ,采用固相萃取 (SPE)进行试样富集、净化 ,高效液相色谱 (HPLC)进行分离检测。方法的最小检出量为 0 3ng ,最低检出浓度 0 2mg kg ,线性范围在 0 334～ 16 7μg mL之间 ,平均回收率为 72 1%～ 131 7%。该方法具有简便、快速、可靠、容易推广等优点。     

高效液相色谱-示差折光法测定保健食品中的低聚木糖

目的建立高效液相色谱-示差折光测定保健食品中的低聚木糖(以木糖计)的方法。方法样品经水提取,在沸水浴中用硫酸水解,用氢氧化钠调成中性后以乙腈+水(70+30)为流动相,通过氨基柱(4.6 mm×250 mm,5μm)分离后用示差折光检测器检测,同一样品在水解前后木糖含量的差值即为样品中低聚木糖的含量。结果被测组分浓度(0.30～4.50 mg/ml)与峰面积线性关系良好(r=0.999 9);相对标准偏差1.86%～3.80%(n=6),在固体保健食品中加标回收率为90.3%～93.6%和92.6%～98.3%;在液体保健食品中加标回收率为89.0%～97.0%和91.0%～96.0%。结论本方法快速、灵敏、重现性好,适用于测定保健食品中的低聚木糖。     

Determination of dl-alpha-tocopherol acetate and dl-alpha-tocopherol in foods by HPLC using post-column photochemical reaction

A reliable analytical method for the simultaneous determination of dl-alpha-tocopherol acetate and dl-alpha-tocopherol in foods was established by HPLC using post-column photochemical reaction with UV and fluorescence detection. For low-fat food such as fruit juice and vegetable sauce, the tocopherols were extracted with methanol containing 0.1% ascorbic acid and the extract solution was injected into the HPLC. For fatty foods such as butter and margarine, the tocopherols were extracted with a mixed solvent of acetonitrile-2-propanol (9:1) containing ascorbic acid. The extract was cleaned up using a Sep Pak plus C18 cartridge and the eluent from the cartridge was injected into the HPLC. The peaks corresponding to tocopherols on the chromatogram were confirmed by comparing their UV spectra with those of the standard mixture at lamp-on and lamp-off of the photochemical reactor. The recoveries of tocopherols from low-fat foods (orange juice and barbecue sauce) fortified at levels of 10 and 100 microg/kg each were 88.3 to 105.8% (RSD 0.5 to 6.0%) and those from the fatty foods (peanut butter and margarine) fortified at 100 microg/kg each were 57.1 to 88.3% (RSD 3.0 to 6.4%). The determination limits corresponded to 10 microg/kg of the tocopherols in the low-fat foods and 20 microg/kg in the fatty foods.     

固相萃取—高效液相色谱法测定食品中的苯并(a)芘

建立了固相萃取—高效液相色谱法测定食品中苯并芘的检验方法,样品经超声萃取,固相萃取净化,C₁₈反相色谱柱进行分离,流动相为乙腈+水（90+10）,流速1.0mL/min,荧光检测器测定食品中的苯并（a）芘,激发波长386nm,发射波长405nm,方法的定量检出限0.32μg/kg,线性范围0ng/mL～1000ng/mL,加标回收率85.0%～95.0%,相对标准偏差优于5%,方法具有操作简便、安全性好、灵敏度高、重复性好和分析时间短等优点。     

高效液相色谱法测定饼干中三氯蔗糖含量

目的 建立高效液相色谱法(high performance liquid chromatography,HPLC)检测饼干中三氯蔗糖含量的分析方法.方法 在现行国家标准基础上,针对饼干样品特点,优化样品前处理方法,并进行方法学验证.结果 该方法工作曲线的线性范围为0.02～0.60 mg/mL,相关系数为0.9999,...     

高效液相色谱法测定保健食品中三氯蔗糖的含量

目的建立一种保健食品中三氯蔗糖含量测定的高效液相色谱检测法。方法样品采用Rad pak C18色谱柱(4.6 mm×250 mm,5μm)进行分离,以1.0 m L/min乙腈:水(V:V=15:85)为流动相,最后用高效液相色谱法(HPLC)-示差折光仪为检测器进行测定,外标法定量分析。结果高效液相色谱法在0.482~2.892 mg/m L浓度范围,三氯蔗糖的浓度和峰面积的线性良好,相关系数为0.999(r0.99),该方法的检出限和定量限分别为19.58 mg/g和65.27 mg/g,在不同的添加水平下,该方法的回收率范围为95.0%~95.6%,相对标准偏差为0.3%(n=9)。结论高效液相色谱法灵敏度、准确度均较高,适用于保健食品中三氯蔗糖的含量测定。     

HPLC-示差折光检测法测定白酒中三氯蔗糖的方法研究

该研究采用高效液相色谱-示差折光检测法测定白酒中的三氯蔗糖含量,从流动相比例、流速、进样量、柱温、示差检测池温度五个方面进行考察,确定最佳色谱条件。结果表明,在流动相为乙腈∶水（20∶80,V/V）、流速1.0 mL/min、进样量20 μL、柱温35 ℃、示差折光检测器温度35 ℃条件下,三氯蔗糖在质量浓度0.01～0.40 mg/mL范围内,线性关系好,相关系数R2=0.999 94,检出限为3.538 μg/mL,定量限为11.79 μg/mL,平均加标回收率为96.3%～103.4%,精密度试验结果相对标准偏差在0.6%～6.6%之间,均能满足检测要求。该方法操作简单、方便快捷、定量准确,适用于白酒中三氯蔗糖含量的大规模、大批量快速检测分析。     

HPLC法测定食品中的叶黄素含量

为了测定食品中的叶黄素的含量,建立方便可靠的测定方法,采用高效液相色谱法对食品中叶黄素含量进行了测定.使用硅胶色谱柱(4.6mm×250 mm,5μm),以环己烷∶乙酸乙酯=75 ∶ 25为流动相,检测波长445nm.该方法最低检出量1.0mg/kg,RSD 为1.2%,加标回收率为93.85.6%,RSD 为3.1%～4.1%.该方法简便、准确,有良好的重现性,技术参数指标符合食品理化分析的要求.     

Determination of sulfite residues in foods by using the modified rankine apparatus and HPLC]

A method for measuring sulfite residues in foods by using the modified Rankine apparatus and HPLC was developed. Sulfites released from foods by bubbling of nitrogen gas and heating for 15 minutes with an electric burner weRe absorbed in 1% triethanolamine solution and detected as sulfite ion by HPLC with a UV detector at 240 nm, using an anion exchange column, IonPac AS9-SC, with 1.8 mmol/L sodium carbonate-1.7 mmol/L sodium hydrogen carbonate solution as the mobile phase. The recoveries of sulfites added to 3 kinds of foods were 98-102%, and the determination limit was 0.001 g/kg. The sulfite values in various kinds of foods determined by the proposed HPLC method were consistent with those obtained by the alkaline titration method and the colorimetric method.     

HPLC法测定食品中的叶黄素含量

为了建立测定食品中的叶黄素含量的可靠方法,采用高效液相色谱法进行了测定.使用硅胶色谱柱(4.6 mm×250 mm,5μm),以环己烷∶乙酸乙酯=75∶25为流动相,检测波长445nm.该方法最低检出量1.0 mg/kg,RSD为1.2%,加标回收率为93.8%～105.6%,RSD为3.1%～4.1%.该方法简便、准确,有良好的重现性,技术参数指标符合食品理化分析的要求.     

固相萃取-高效液相色谱法测定罐头中三氯蔗糖

目的建立固相萃取-高效液相色谱法测定罐头食品中三氯蔗糖含量的分析斱法。方法样品采用乙酸锌和亚铁氰化钾沉淀蛋白,经过HLB固相萃取小柱净化浓缩,再经C_(18)色谱柱分离,采用蒸发光散射检测器(evaporative light-scattering detector, ELSD)检测。结果该斱法在20.26～405.2μg/mL范围内以三氯蔗糖浓度的对数和相应峰面积的对数做标准曲线,相关性良好(r~2=0.9996)。平均加标回收率为99.6%～105.3%,检出限为0.48 mg/kg。结论该斱法准确、灵敏,能有效、快速的测定罐头食品中的三氯蔗糖。