Indirect determination of carbohydrates in wort samples and dietetic products by capillary electrophoresis

The first total separation by electrophoresis of five carbohydrates, sucrose, maltotriose, maltose, glucose and fructose, is described. The basic technique requires 1‐naphthylacetic acid as background electrolyte at pH 12.5, indirect UV detection at 222 nm, with a capillary of 75 µm × 120 cm and a voltage of 25 kV. Linear calibration curves from 50 to 400 mg l^?1 with a good correlation coefficient were obtained. The method has been used to determine carbohydrates during the brewing process of a non‐alcoholic beer and also to analyse the carbohydrate content of dietetic fruit juices and chocolate. Copyright © 2004 Society of Chemical Industry     

Predicted intake of trace elements and minerals via household drinking water by 6-year-old children from Krakow,Poland. Part 5: Zinc

Zinc (Zn) exposure in pre-school children via household drinking water collected by a double sampling method (morning, evening) was evaluated in a sample of the Polish population. Zn concentration was measured by flame atomic absorption spectrometry. Rural and suburban Krakow sites were non-distinguishable in respect of Zn concentrations. However, significantly lower Zn was found in urban as compared with non-urban sites [geometric mean (95% confidence interval) 0.14 (0.01–1.95) mg l^?1 versus 0.52 (0.03–10.2) mg l^?1, p < 0.001.] Zn levels in water standing overnight in pipelines were higher in all sites by 0.36 mg l^?1 on average, but observed really contaminations were higher. The Zn limit based on the taste and colour of drinking water (3 mg l^?1) was exceeded in 1% and 10% of households from urban and non-urban sites, respectively. The Zn intake predictions for evening water samples for 6-year-old children averaged between 2% and 9% of the recommended dietary allowance (RDA, 10 mg day^?1) for urban and non-urban sites, respectively. Mean Zn intake prediction for the exceedance fraction was 64% of RDA. In conclusion, overnight contamination of drinking water from in-house pipelines was significant and common to all sites investigated. Secondly, drinking water can be considered a significant contributor to dietary Zn intake by children in non-urban sites and may shift the population borderline of deficiency.     

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     

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。     

高效毛细管电泳法测定胭脂虫提取物中胭脂红酸

建立高效毛细管电泳法(HPCE)测定胭脂虫提取物中胭脂红酸含量的方法以含5% 乙腈、5% 乙二醇的40mmol/LNa2HPO4-Na2B4O7·10H2O 混合缓冲液(pH9.434)为背景电解质,60cm × 75μm 未涂层毛细管柱为分离泳道,分离电压20kV,0.5psi × 10s 压力进样,柱温25℃,检测波长239nm,此条件下,采用峰面积内标法定量;在选定的电泳条件下,胭脂红酸质量浓度在50～500mg/L 范围内线性关系良好,线性相关系数R=0.9958,加标回收率为100.86%,方法检出限(RSN=3)为5.00μg/mL。本方法测定胭脂红酸含量试剂用量少,简便、快速、准确,可应用于实际生产中胭脂红酸的测定。     

Rapid determination of nitrites in food using a diffuse UV-visible reflectance method

A simple, low-cost, sensitive and selective method for the determination of trace quantities of nitrite in foods such as cheese and cured meat using diffuse ultraviolet-visible reflectance was developed. It is based on the reaction of nitrite with sulphadiazine and α-naphthol, which produces a coloured product in basic medium. The reaction is carried out directly in the measuring cell. For cheese the limit of detection (LOD), expressed as NaNO₂, was estimated to be about 2.0?×?10^?2?mg?l^?1 (2.9?×?10^?7?mol?l^?1) in the final measuring solution and 0.17?mg?kg^?1 in cheese (2.5?×?10^?6?mol?kg^?1). The relative standard deviation (RSD) varied from 5% to 8% depending on the sample. For meat the LOD was estimated to be about 2.0?×?10^?2?mg?l^?1 (2.9?×?10^?7?mol?l^?1) in the final measuring solution and 0.13?mg?kg^?1 in meat (1.9?×?10^?6?mol?kg^?1). The RSD varied from 3% to 6% depending on the sample. The results of the proposed method were also compared with those obtained with the official method using the statistical Student's t-test and F-test procedures.     

LIF-HPCE法检测食品中的黄曲霉毒素B1

采用自行设计搭建的激光诱导荧光(LIF)- 高效毛细管电泳(HPCE)检测平台,建立LIF-HPCE 法对食品中的黄曲霉毒素B1(AFB1)进行高灵敏度检测。AFB1 在胶束电动毛细管电泳(MECC)模式下分离,LIF 检测,375nm 激光进行激发,检测波长440nm,操作电压15kV,电流104μA。AFB1 在0.5～50μg/kg 浓度范围内线性关系良好,r ＝ 0.9994;最低检出质量1.7 × 10-13g(S/N ＝ 3),最低定量限5.6 × 10-13g(S/N ＝ 10),方法精密度和重复性的相对标准偏差为5% 左右。测定食品中粮油等食品样品,加标回收率为84.1%～96.1%。所建立的方法无需进行衍生反应和荧光标记,快速灵敏,绿色环保,10min 左右完成分析,适用于食品中黄曲霉毒素的高灵敏度检测。     

Feasibility of using capillary zone electrophoresis with photometric detection for the trace level detection of bromate in drinking water

The feasibility of applying a capillary zone electrophoretic (CZE) method for the trace analysis of bromate, a suspect human carcinogen, in drinking water was studied. Using a bare fused-silica capillary (75 µm inner diameter) coupled with indirect ultraviolet detection (200 nm), 0.25 mM cetyltrimethylammonium bromide, 5% methanol and 5.0 mM phthalate at pH 5.0–5.2, an electrokinetic injection of 15 kV and 10 s, a separation voltage of 18 kV (negative polarity) and a capillary temperature of 15°C, bromate was detected in high purity water at ≤10 µg l^?1. The method was applied to three bottled water sources and to local municipal water. If needed, additional sample-handling steps, consisting of an off-line pre-concentration step and pH adjustment to 5.5, was used to improve detection limits (from a high of 400 µg l^?1 to ≤10 µg l^?1) and baseline noise. Signal-to-noise ratios also increased by adding sodium phosphate (1.1 µg ml^?1) to all sources prior to analysis. Although the CZE method was capable of detecting bromate at levels ≤10 µg l^?1 with an analysis time of 8–9 min, high variability (>10% relative standard deviation) precluded its application to some of sources without further method development. Nonetheless, this method could serve as the basis for the detection of bromate to specific water sources with minimal or no optimization     

Effects of different inorganic salts and organic nutrient components on the growth of Lentinula edodes (Shiitake) mycelium on solid medium

The influence of 11 inorganic salts and various organic nutrients on the mycelial growth of Lentinula edodes (Berk) Pegler (Shiitake) on solid medium was studied. All of these inorganic salts exerted concentration‐dependent inhibitory effects. Nitrite caused the strongest inhibition: 8 mM nitrite inhibited the growth completely. The inhibitory effect of nitrite could be reduced by the addition of ascorbic acid or a black tea extract. The effects of the addition of the different organic nutrients were investigated in order to optimize the composition of the culture medium. The medium containing malt extract (15 g l^?1), starch (3 g l^?1) and oak wood chips (20 g l^?1) proved best for mycelial growth. Growth was not promoted by components with a high organic nitrogen content. Copyright © 2003 Society of Chemical Industry     

Hydroxymethylfurfural determination in infant milk-based formulas by micellar electrokinetic capillary chromatography

A procedure for determining hydroxymethylfurfural (HMF) in milk-based products by micellar electrokinetic capillary chromatography (MECC) was settled on. The effect of the trichloroacetic acid on the migration time of HMF and presence of interference peaks were investigated. MECC procedure was applied on commercial liquid infant formulas and compared with the classical reversed-phase high performance liquid chromatography method, giving similar values of repeatability and recovery. HMF peak was well-resolved by using an uncoated fused-silica capillary (48.5 cm×50 μm i.d.) with 50 mM phosphate buffer (pH 7.5) containing 100 mM SDS as electrolyte, voltage at 20 kV (25°C). Sample injection was by pressure (50 mbar, hydrodynamic) for 2.5 s. HMF analysis by MECC was suitable for routine analysis since separation was completely achieved at 5 min.     

Optimal conditions for determination of zinc bacitracin,polymyxin B,oxytetracycline and sulfacetamide in animal feed by micellar electrokinetic capillary chromatography

A separation technique for zinc bacitracin, polymyxin B, oxytetracycline and sulfacetamide in animal feedstuffs by micellar electrokinetic capillary chromatography (MEKC) was developed. The running buffer was 20 mmol l^?1 borate, 20 mmol l^?1 phosphate, pH 8.4, containing 20 mmol l^?1 sodium dodecylsulphate and 10% (v/v) methanol. MEKC was performed at 25°C; the applied voltage was 25 kV with a running pressure of 10 mbar. Simultaneous UV detection for all analytes was at 215 nm. The method was validated for specificity, accuracy, linearity, precision and robustness. It was shown to be specific, accurate (recoveries were 99.7?±?0.3, 99.9?±?0.9, 99.8?±?1.0 and 99.5?±?0.4, respectively, for oxytetracycline-, sulfacetamide-, polymyxin B- and zinc bacitracin-spiked samples of feed for cow, pigs, chicken and cattle), linear over the tested range (correlation coefficients ≥0.9987) and precise (RSDs below 1.8% for each analyte). The method was applied to determine zinc bacitracin, polymyxin B, oxytetracycline and sulfacetamide as additives in animal feed.     

Multi‐residue analysis of sulfonamides in animal tissues by capillary zone electrophoresis with electrochemical detection

BACKGROUND: The objective of this study was to adapt and improve previously published analysis methods aimed at the simultaneous determination of sulfonamide residues in edible animal tissues by capillary zone electrophoresis with electrochemical detection. RESULTS: The effects of several factors such as the acidity and concentration of running buffer, the separation voltage, the applied potential and the injection time on CZE‐ED were investigated. Complete separation of six sulfonamides was achieved within 17 min by using 40 mmol L^?1 Na₂B₄O₇/25 mmol L^?1 KH₂PO₄ (pH 6.2) at an applied voltage of 18 kV. Excellent linearity was obtained over two orders of magnitude with the improved detection limits (S/N = 3) ranged from 1.7 × 10^?7 to 4.4 × 10^?9 g mL^?1 for all six sulfonamides in comparison with previous reports. A solvent extraction/centrifuge/evaporation procedure was used to extract sulfonamides from animal tissues, sample clean‐up and pre‐concentration of sulfonamides prior to CZE‐ED analysis. Good recoveries from 81% to 92% were achieved. CONCLUSION: Results obtained in this work indicated that the proposed CZE‐ED method was sensitive, rapid and simple for the simultaneous determination of sulfonamides in edible animal tissues. Therefore, the new faster and easy handling procedure provides an additional powerful tool that can be employed for the analysis of sulfonamide residues in foodstuff. Copyright © 2009 Society of Chemical Industry     

Multiresidue method for the determination of 77 pesticides in wine using QuEChERS sample preparation and gas chromatography with mass spectrometry

A method based on a QuEChERS (quick, easy, cheap, effective, rugged, safe) sample preparation method and gas chromatography with mass spectrometric detection by selected ion monitoring (GC/MS-SIM) was developed for simultaneous determination of 77 pesticide residues in wine. An extraction of 10 ml of sample with acetonitrile followed by liquid–liquid partition formed by the addition of 4 g MgSO₄ and 3 g NaCl was applied in the sample preparation. The clean-up was carried out by applying dispersive solid-phase with 150 mg MgSO₄ as well as 50 mg primary secondary amine (PSA). One quantitation ion and at least two identification ions were selected in the analytical method for each pesticide compound by GC/MS. The recovery data were obtained by spiking blank samples at two concentration levels (0.05 and 0.2 mg l^?1). The recoveries of all pesticides were in the range 70–110%, with intra-day precision of less than 15%, and the inter-day precision of less than 22% and 15% for 0.05 and 0.2 mg l^?1 fortification levels, respectively. Linearity was between 0.02 and 2 mg l^?1 with determination coefficients (R ²) greater than 0.98 for all compounds. The limits of quantification (LOQs) for the 77 pesticides ranged from 0.003 to 0.05 mg l^?1. This method was applied for routine analysis in market products.     

Impact of non-selective fungicides on the growth and production of ochratoxin A by Aspergillus ochraceus and A. carbonarius in barley-based medium

The aim of this study was to assess the influence of the non-selective fungicides mancozeb, copper oxychloride, and sulfur on the growth and capability for producing ochratoxin A (OTA) of ochratoxigenic isolates of Aspergillus carbonarius and A. ochraceus in barley-based medium. Lag phases and growth rates were determined for each fungicide at different doses, at 15°C and 25°C and at 0.97?a_w . Mancozeb at 40?mg?l^?1 inhibited fungal growth and provided lag phases >24 days at 10–20?mg?l^?1 and 15°C. OTA was observed only at 25°C and doses <10?mg?l^?1. At 15°C, copper oxychloride proved inhibitory at 800?mg?l^?1, while at 25°C growth was not delayed and only high doses decreased OTA levels. Sulfur was inhibitory or provided large lag phases at 5–8?g?l^?1 (at 15°C) while at 25°C growth took place even at 8?g?l^?1, although OTA levels were low or undetectable. The antifungal activity decreased in the order mancozeb?>?copper oxychloride?>?sulfur, and was lower at 25°C than at 15°C. OTA accumulation was affected by the type of fungicide, dose, temperature and time. The efficacy of these fungicides on the growth of A. carbonarius and A. ochraceus and OTA production in barley-based medium is assessed for the first time.     

Effects of tuber storage protein of yam (Dioscorea alata cv. Tainong No. 1) and its peptic hydrolyzates on spontaneously hypertensive rats

Yam storage protein (YSP) was purified from tubers of Dioscorea alata L. Tainong No. 1 (TN1) to homogeneity by DE‐52 ion‐exchange chromatography. The short‐term (24 h) and long‐term (25 days) antihypertensive effects of YSP‐TN1 and its peptic hydrolyzates (PH‐TN1) were measured in spontaneously hypertensive rats (SHRs). For 24‐h antihypertensive measurements, SHRs (age 10 weeks, body weight from 240 to 250 g) were administered orally once (YSP‐TN1 and PH‐TN1, 40 mg kg^?1 SHR) to measure the mean blood pressure (MBP), systolic blood pressure (SBP) and diastolic blood pressure (DBP). For a long‐term antihypertensive measurement, SHRs (age 12 weeks, body weight from 250 to 270 g) were administered orally once a day for 25 days (YSP‐TN1, 40 mg kg^?1 SHR) to measure SBP, DBP and MBP. Captopril (10 or 15 mg kg^?1 SHR) was used as a positive control. It was found that short‐term administration of 40 mg kg^?1 SHR of YSP‐TN1 and PH‐TN1 effectively lowered SHRs' MBP, SBP and DBP (For YSP‐TN1, the lowest blood pressure was reached in the fourth hour and for PH‐TN1 in the eighth hour). The lasting effects of PH‐TN1 on reduced SHRs' BP were better than those of YSP‐TN1 for one oral administration. For oral administration of 40 mg YSP‐TN1 kg^?1 SHR, the reduced MBP was 21.5 mmHg, which was comparable to 25.2 mmHg (the fourth hour) of 10 mg captopril kg^?1 SHR oral administration. For oral administration of 40 mg PH‐TN1 kg^?1 SHR, the reduced MBP was 33.7 mmHg, comparable to 38.4 mmHg (the fourth hour) of 15 mg captopril kg^?1 SHR. For long‐term 25‐day oral administration of 40 mg YSP‐TN1 kg^?1 SHR once a day, it was found that a feeding trial of YSP‐TN1 effectively lowered SHRs' SBP, DBP and MBP. The greatest reduction in SHRs' blood pressure was reached on the ninth day, for the reduced SBP, 27.7 mmHg; for the reduced DBP, 28.3 mmHg; and for the reduced MBP, 27.5 mmHg. Copyright © 2006 Society of Chemical Industry     

The development of a goat's milk yogurt

This study sought to establish conditions suitable for a small‐scale yogurt process using goat's milk and to examine the physicochemical properties (pH, titratable acidity, solids‐not‐fat (SNF), viscosity, texture) and organoleptic acceptability (preference by Filipino panellists) of the resultant product. Goat's milk was concentrated by heating (80 °C, 1 h), which resulted in an increase in SNF from 85 to 110 g kg^?1. To further improve the curd of goat's milk yogurt, two hydrocolloids were used: carrageenan (1.5 and 3 g l^?1) and pectin (50 g l^?1). The addition of dehydrated pineapple and banana cubes (50 and 100 g l^?1) in a sundae‐style formulation increased the SNF by an additional 2.5% and produced a curd that was firmer than the control, plain set yogurt. The use of carrageenan appeared to be a convenient way of controlling product viscosity. In terms of product preference and firmness the fruit‐flavoured sundae‐style yogurts were ranked higher by sensory panellists. Copyright © 2005 Society of Chemical Industry     

Postharvest response of ‘Brown Turkey’ figs (Ficus carica L.) to the inhibition of ethylene perception

The potential use of 1‐methylcyclopropene (1‐MCP) alone or as a supplement to cold storage to delay the softening of ‘Brown Turkey’ figs (Ficus carica L.) was studied. Figs were treated with 0, 0.25, 0.5 or 5 µl l^?1 1‐MCP at 25 °C for 8 h and stored at 20 °C until evaluated. Figs treated with 0.5 or 5 µl l^?1 1‐MCP had higher ethylene production and respiration rates but slower softening than untreated fruit and those treated with 0.25 µl l^?1 1‐MCP. Early‐harvested firm figs and late‐harvested soft figs were untreated or treated with 0.5 or 5 µl l^?1 1‐MCP at 25 °C and stored at 0 °C for 19 days. Firm figs treated with 1‐MCP showed an early peak in ethylene synthesis, higher respiration rate and were firmer than control fruit. In contrast, soft figs did not respond to 1‐MCP except for a late increase in respiration rates of fruit treated with 5 µl l^?1 1‐MCP. 1‐MCP appeared to have a relatively limited effect on slowing ripening of ‘Brown Turkey’ figs and its effect was influenced by ripening stage. Copyright © 2005 Society of Chemical Industry     

The use of FT‐IR microspectroscopic mapping to study the effects of enzymatic retting of flax (Linum usitatissimum L) stems

Fourier transform infrared (FT‐IR) microspectroscopic mapping was investigated as a tool to study the effects of enzymatic retting of flax stems. The FT‐IR technique permitted the elucidation of the relative loss or changes in the distribution of key chemical components after treatment with enzymes or enzyme/chelator mixtures in association with visible changes in structure. Cross‐sections of Ariane flax stems were treated with SP 249 (a pectinase‐rich enzyme mixture from Novo Nordisk) at 0.5, 0.7 or 1.0 ml l^?1 concentration in pH 5 acetate buffer for 6 h at 40 °C. Flax stems treated with 0.5 or 0.7 ml l^?1 SP 249 and 50 mM oxalic acid as a chelator were also investigated by the technique. The results indicated that treatment with 0.5 ml l^?1 SP 249 alone was ineffective in releasing the fibre bundles from the surrounding tissue, but the release was increased by the addition of 50 mM oxalic acid as a likely chelator for the cations of pectate salts. However, the IR spectra of the bundles indicated that an insoluble oxalate salt remained on the tissue after this treatment. Increasing the concentration of SP 249 to 0.7 ml l^?1 plus 50 mM oxalic acid was effective in releasing the fibre bundles and generating some ultimate fibres with no detectable oxalate expectate salt residues. Increasing the SP 249 concentration to 1.0 ml l^?1 without using oxalic acid was effective in separating the fibre bundles into ultimate (individual) fibres, leaving no pectate salt residue and only a trace of pectic esters and/or acids. The use of infrared mapping, or so‐called chemical imaging, is shown to have advantages over visible imaging alone in that it can detect and locate the chemical species present after each treatment in relation to the anatomical features of the flax stem. This analytical tool shows promise as a technique by which to study the effects of enzymatic treatment of natural fibre materials. Published in 2002 for SCI by John Wiley & Sons, Ltd     

Influence of post-harvest application rates of cyprodinil,treatment time and temperature on residue levels and efficacy in controlling green mould on ‘Valencia’ oranges

The effectiveness of heat treatments with water and cyprodinil in controlling post-harvest green mould caused by Penicillium digitatum was investigated on artificially inoculated ‘Valencia’ oranges. Residue levels of cyprodinil were determined in the oranges as a function of active ingredient concentration, temperature and treatment time. Cyprodinil residues were significantly dependent on treatment time when applied at 600 mg l^?1 and 20°C, but not when fruit were treated at 150–300 mg l^?1. The application of cyprodinil at 50 or 100 mg l^?1 at 55°C for 30 s produced similar residue levels, while residues increased when the application rate was 150 mg l^?1. Cyprodinil at 100 mg l^?1 and 60°C produced a significant increase in residues compared to treatment at 50 mg l^?1; no significant increase in residues was found when the application rate was raised from 100 to 150 mg l^?1. In comparison to treatments performed at 20°C, the application of a heated cyprodinil mixture resulted in significantly higher residues in fruit. All treatments with cyprodinil at 20°C similarly reduced green mould after 7 days of storage at 20°C. After 18 days, treatment with cyprodinil at 600 mg l^?1 for 30 s was more effective than at 150–300 mg l^?1. When dip time was extended to 90 or 180 s, treatment efficacy was positively related to fungicide concentration. Treatments with water at 55°C for 30 s were as effective as cyprodinil at 50–100 mg l^?1, but less effective than cyprodinil at 150 mg l^?1. After 7 days, treatment with water or cyprodinil at 50–150 mg l^?1 and 60°C were equally effective in controlling green mould; while, after 18 days, treatment with cyprodinil at 150 mg l^?1 was consistently more effective than at 50–100 mg l^?1 or hot water alone.     

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