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。     

微生物法测定发酵食品中维生素B12含量的研究

为明确发酵食品中维生素B12的含量及分布,利用微生物法对大豆发酵食品（3种类型腐乳、韩国大酱、纳豆、豆汁）及奶酪中维生素B12的含量进行了测定。结果表明,在3种腐乳中,臭腐乳维生素B12含量最高,达到（3.57±1.08） μg/100 g,红腐乳和白腐乳分别为（0.48±0.21） μg/100 g和（0.41±0.16） μg/100 g;除腐乳外,纳豆（0.50 μg/100 g、0.20 μg/100 g）、韩国大酱（0.97 μg/100 g、0.10 μg/100 g）、豆汁（熟）（0.52 μg/100 g）的维生素B12含量均低于臭腐乳。虽然个别奶酪样品中维生素B12含量最高可达1.54 μg/100 g,但其总体维生素B12的分布及含量也均低于臭腐乳。     

高效液相色谱法测定玉米浆干粉中维生素B6的含量

建立了高效液相色谱法测定玉米浆干粉中维生素B6含量的方法。色谱条件为Symmetry-C18柱（3.9mm×150mm,5μm）;流动相:A相为甲醇,B相为含0.05g/L EDTA和1.1g/L庚烷磺酸钠的2.5%乙酸溶液（pH3.40）,以A∶B为1∶6比例等度洗脱;流速为0.8mL/min;柱温为30℃;检测波长为280nm;样品分析时间为10min。结果表明,维生素B6的线性范围为0.10¹00.00μg/mL（r=0.9999）,日间和日内精密度均小于15%,低、中、高三种浓度下玉米浆干粉样品中维生素B6的提取回收率分别平均为93.66%±1.38%、95.60%±2.77%、93.52%±2.46%（n=4）。此法操作简便、快速、准确,可作为玉米浆干粉中维生素B6含量的检测方法。      

微生物法测定肠内营养粉剂中微量维生素 B12的含量

目的建立微生物法测定肠内营养粉剂中微量维生素B_(12)的含量。方法以莱士曼氏乳酸杆菌为实验菌,在测定用培养基中供给除维生素B_(12)以外的所有营养成分,(36±1)℃培养19~20 h,采用比浊法测定。结果维生素B_(12)在0.001~0.010 ng/mL浓度范围内线性关系良好,肠内营养粉剂中维生素B_(12)的含量为2.9μg/100 g。结论该方法检测结果准确、可靠,适用于肠内营养粉剂中微量维生素B_(12)的含量测定。     

Determination of sucralose in foods by HPLC

A method for the determination of sucralose in various foods by RI-HPLC and ion chromatography with a pulsed amperometric detector (PAD-IC) was developed. Chopped or homogenized samples were packed into cellulose tubing with 0.01 mol/L hydrochloric acid containing 10% sodium chloride and were dialyzed against 0.01 mol/L hydrochloric acid for 24 hours. The dialyzate was passed through a Bond Elut ENV cartridge, and the cartridge was washed with 0.2 mol/L NaOH and water. Sucralose was eluted from the cartridge with methanol. The extract was taken to dryness in an evaporator and the residue was re-dissolved in water. Sucralose was separated on an Inertsil ODS-3V column with a mobile phase of acetonitrile-water (15:85) and an RI detector. It was also determined on a CarboPak PA1 column with a mobile phase of 100 mmol/L NaOH-75 mmol/L CH3COONa, using a PAD detector. The recoveries of sucralose from various kinds of foods spiked at 50 micrograms/g and 200 micrograms/g ranged from 88-105%. The detection limit in samples was 10 micrograms/g for RI-HPLC and 1 microgram/g for PAD-IC.     

Determination of vitamin D in foods: a review.

Determining vitamin D content in foods is difficult because in natural foods of highest vitamin D activity, and even in vitamin D-fortified foods, only small quantities are present, and many other compounds are extracted along with vitamin D that cause difficulties in purifying the extract or in the spectrophotometry or colorimetry that follows. Several physicochemical methods--such as spectrophotometric, colorimetric, thin-layer chromatographic, adsorption, partition, gas-liquid, and high-performance column chromatographic--have been tried for assay foods for vitamin D, but none of them have been accepted for official or routine use; they are time consuming and expensive, or lack the required sensitivity, precision, or accuracy. Curative biological assays, based on degree of healing of a leg bone of rats previously made rachitic, is the generally accepted method to determine vitamin D content of foods. However, that method also requires too much time and is expensive. The recently developed high-performance liquid chromatographic method may offer the most for establishing a satisfactory physicochemical method for determining vitamin D in foods. Many of the difficulties and problems in assaying foods for vitamin D are discussed.     

HPLC法同时测定保健食品中维生素A和维生素E

建立了高效液相色谱法(HPLC)同时测定保健食品中VA、VE的方法。样品预处理采用经二甲亚砜和正己烷的混合溶液于60℃剧烈振摇提取30min,离心后吸取正己烷层,合并3次提取的溶液后直接进行液相色谱测定。方法采用Inertsil氨基柱(4.6 mm×250 mm,5μm),以含0.1%异丙醇的正己烷为流动相进行等度洗脱,流速为1.0 m L/min,检测波长为280nm,柱温为25℃。结果表明,VA、VE分别在5~25μg/m L、100~500μg/m L范围内线性关系良好,相关系数分别达0.9997和0.9998,保留时间和峰面积的日内和日间精密度均较好,平均加标回收率在97.53%~100.67%之间,相对标准偏差(RSD)均小于2.0%。与相应的检验标准测定结果比较,相对偏差均小于1.0%,无明显差异。该方法快速、准确、可靠,适用于不同厂家、不同配方的保健食品中添加合成VA、VE的同时定量测定。     

Determination of vitamin a in foods ‐ a review

Formerly, few foods were routinely analyzed for vitamin A, but recent emphasis on nutrient requirements, nutrient labeling, and use of dietary convenience foods has created need for determining vitamin A in a variety of foods. There are many vitamin A methods — some suitable for certain products only. For regulatory purposes, the FDA specifies the AOAC method where it is applicable. However, some food analysts and organizations continue with their own vitamin A methods. If possible, a single, widely applicable general method should be used for vitamin A in foods. Vitamin A may be determined by spectrophotometric, colorimetric, and fluorometric procedures. Sometimes chromatography is required as an important part of the method. Colorimetric procedures with SbCl₃ are now most widely used to measure vitamin A (retinol) in foods. If vitamin A content is high enough and extracts sufficiently free of interfering substances, spectrophotometric or flurometric methods are satisfactory. Methods in various stages of development for determining vitamin A in foods are based on flurospectrophotometry, gas‐liquid chromatography, high‐performance liquid chromatography, and automation. To estimate total vitamin A nutritional value of certain foods may also require determination of vitamin A isomerization and contents of carotenes, cryptoxanthin, reinaldehyde, and apo‐carotenal.     

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。     

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.     

Determination of vitamin e in foods — a review

The vitamin E group includes tocopherols and tocotrienols and their isomers, esters, and derivatives. They differ not only in biopotencies as antisterility agents but also in activities in other physiological and chemical relationships. Unlike vitamins A and D, foods (vegetable oils) are among the richest sources of vitamin E, and assay methods for vitamin E include food applications more often than for the former vitamins. Phys‐icochemical methods are replacing bioassays for vitamin E and tocopherol wherever possible because of greater specificity and less variability, time, and, sometimes, expense. Unless careful purifications and isolations are carried out and some of the relative vitamin E activities of components are calculated, bioassays are still required for total vitamin E activity. The vitamin E group is separated by column, paper, thin‐layer, gas‐liquid, and high‐pressure liquid chromatography (HPLC): Gas‐liquid chromatography has been more successfully used for vitamin E than for other fat‐soluble vitamins. Recently developed HPLC methods for vitamin E are sensitive and apparently require less cleanup of extracts and less time than former methods; HPLC may prove to be the most useful technique for vitamin E in foods, especially if other fat‐soluble vitamins can be determined simultaneously on the same sample extract.     

甲醇超声提取法测定保健食品中维生素A

目的 采用甲醇超声方法提取保健食品中的维生素A。用高效液相色谱法(high performance liquid chromatography, HPLC)法进行含量测定, 并与GB/T 5009.82-2016进行比较, 同时进行方法学验证。方法 样品前处理方法为甲醇超声提取法。采用C18(4.6 mm×250 mm, 5 μm)色谱柱, 甲醇为流动相, 检测波长为325 nm, 流速为1 mL/min, 柱温为30 ℃, 进样量为20 μL。结果 超声时间为5~15 min提取效率最高, 工作曲线在1.00~10.00 μg/mL范围内线性关系良好, 相关系数为0.9998, 相对标准偏差为1.82% (n=6), 平均回收率为101.09%, 方法检出限为10 μg/100 g, 定量限为31 μg/100 g。结论 和国标法相比, 本方法操作简单、准确度高, 适用于保健食品中维生素A含量的测定。     

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.     

Influence of extraction on the determination of vitamin B6 in food by HPLC

 The effect of the extraction procedure on the total vitamin B₆ content in different food matrices is presented. The use of hydrochloric acid, sulphuric acid and trichloroacetic acid, combined with enzymatic hydrolysis using several commercial enzyme preparations, was tested. The results of two liquid chromatographic methods (isocratic and gradient elution) and those of microbiological assay were compared. Reproducible results were achieved using a mineral acid followed by β-glucosidase/acid phosphatase hydrolysis for extraction of the same sample and only a few unknown compounds caused interference in the reversed-phase chromatogram. However, the conversion efficiency of the enzyme preparation should always be checked. The liquid chromatographic method indicated that there was a higher vitamin content compared with the microbiological assay. This is probably due to a lower growth response of Saccharomyces with pyridoxamine and pyridoxal rather than pyridoxine. Received: 5 March 1996/Revised version: 22 July 1996     

Influence of extraction on the determination of vitamin B6 in food by HPLC

 The effect of the extraction procedure on the total vitamin B₆ content in different food matrices is presented. The use of hydrochloric acid, sulphuric acid and trichloroacetic acid, combined with enzymatic hydrolysis using several commercial enzyme preparations, was tested. The results of two liquid chromatographic methods (isocratic and gradient elution) and those of microbiological assay were compared. Reproducible results were achieved using a mineral acid followed by β-glucosidase/acid phosphatase hydrolysis for extraction of the same sample and only a few unknown compounds caused interference in the reversed-phase chromatogram. However, the conversion efficiency of the enzyme preparation should always be checked. The liquid chromatographic method indicated that there was a higher vitamin content compared with the microbiological assay. This is probably due to a lower growth response of Saccharomyces with pyridoxamine and pyridoxal rather than pyridoxine. Received: 5 March 1996/Revised version: 22 July 1996     

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.     

液相色谱-串联质谱法测定保健食品中维生素B12

目的 建立测定保健食品中维生素B12的液相色谱-串联质谱法.方法 样品添加内标人参皂苷Re溶液,固相萃取法( SPE)对试样进行富集、净化,以甲醇(A)和纯水(B)为流动相经Bio Basic-18 PIONEER柱(150 mm×2.1 mm,5μm)梯度洗脱分离,串联离子阱质谱在电喷雾电离正离子(ESI+)-全扫描(full)-二级质谱(MS/MS)模式下按内标法测定.结果 维生素B12在50～500 ng/ml范围内具有良好的线性,相关系数r=0.992,回收率75.2％ ～ 89.5％,精密度3.6％～5.9％,检出限为5 ng/g,定量限为16 ng/g.结论本法可应用于保健食品的检测或产品质量控制.     

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.     

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。