Analysis of raw materials, intermediates and subsidiary colours in Food Yellow No. 5 (Sunset Yellow FCF) by LC/MS

Raw materials, intermediates and subsidiary colours in Food Yellow No. 5 (Sunset Yellow FCF) were determined using liquid chromatography/mass spectrometry (LC/MS) with electrospray ionization. A gradient consisting of acetonitrile and 0.04% aqueous ammonium carbonate solution was used for the HPL C mobile phase. Quasi-molecular ions of impurities were used as monitor ions. It was necessary to use fragment ions of the sodium salts of 6-hydroxy-5-phenylazo-2-naphthalenesulphonic acid (SS-AN) and 4-(2- hydroxy-1- naphthylazo) benzenesulphonic acid (2N-SA) as monitor ions because the compounds are not resolved by chromatography and have the same molecular weight. Fifteen samples of commercial Sunset Yellow FCF were examined. The results obtained by UV-Vis spectroscopy were in good agreement with the results of LC/MS analyses. The detection limits of the impurities in Sunset Yellow FCF ranged from 0.01 to 0.1%.     

Analytical applications of 2,6-diacetylpyridine bis-4-phenyl-3-thiosemicarbazone and determination of Cu(II) in food samples

New synthesized reagent 2,6-diacetylpyridine bis-4-phenyl-3-thiosemicarbazone (2,6-DAPBPTSC) is proposed as a sensitive and selective analytical reagent for the spectrophotometric determination of copper(II) at pH 3.0 to form a yellowish orange colored 1:1 chelate complex. The maximum absorbance was measured at 370 nm. This method obeys Beer’s law in the concentration range 0.63–6.30 g ml⁻¹ and the correlation coefficient of Cu(II)–2,6-DAPBPTSC complex is 0.942, which indicates an adequate linearity between the two variables with good molar absorptivity and Sandell’s sensitivity, 0.847 × 10⁴ l mol⁻¹ cm⁻¹ and 0.0075 g cm⁻², respectively. The instability constant of complex calculated from Asmus′ method is 1.415 × 10⁻⁴ at room temperature. The precision and accuracy of the method is checked with calculation of relative standard deviation (n = 5), 0.777% and the detection limit value is 0.0056 g ml⁻¹. The interfering effect of various cations and anions has also been studied. The method was successfully applied for the determination of Cu(II) in food samples. The performance of present method was evaluated in terms of Student ‘t’ test and Variance ‘f’ test, which is indicates the significance of present method is an inter comparison of the experimental values, using atomic absorption spectrometer (AAS).     

Utility of solid phase spectrophotometry for the modified determination of trace amounts of cadmium in food samples

A modified selective, highly sensitive and accurate procedure for the determination of trace amounts of cadmium which reacts with 1-(2-benzothiazolylazo)-2-hydroxy-3-naphthoic acid (BTAHNA) to give a deep violet complex with high molar absorptivity (7.05 × 10⁶ L mol⁻¹ cm⁻¹, 3.92 × 10⁷ L mol⁻¹ cm⁻¹, 1.78 × 10⁸ L mol⁻¹ cm⁻¹, and 4.10 × 10⁸ L mol⁻¹ cm⁻¹), fixed on a Dowex 1-X8 type anion-exchange resin for 10 mL, 100 mL, 500 mL, and 1000 mL, respectively. Calibration is linear over the range 0.2-3.5 μg L⁻¹ with RSD of ?1.14% (n = 10). The detection and quantification limits were calculated. Increasing the sample volume can enhance the sensitivity. The method has been successfully applied for the determination of Cd(II) in food samples, water samples and some salts samples without interfering effect of various cations and anions.     

Selective determination of copper and iron in various food samples by the solid phase extraction

The solid phase extraction method developed using N-benzoyl-N-phenylhydroxylamine as a chelating reagent and Amberlite XAD-1180 as an adsorbent was used for the determination of Cu(II) and Fe(III) in various food samples by flame atomic absorption spectrometry. The samples were digested by using nitric acid and hydrogen peroxide. The Cu concentrations ranged from 1.01 to 5.81 μg g⁻¹ in cereals, from 0.40 to 9.67 μg g⁻¹ in vegetable and fruits and from 0.37 to 0.70 μg g⁻¹ in infusions while the Fe concentrations ranged from 7.48 to 34.3 μg g⁻¹ in cereals, from 5.74 to 260 μg g⁻¹ in vegetable and fruits, from 1.63 to 5.12 μg g⁻¹ in infusions and from 0.24 to 1.56 mg L⁻¹ in beverage samples. The Cu and Fe concentrations found were compared with the results obtained from the other food studies in the world.     

Estimate of the theoretical maximum daily intake of Sunset Yellow FCF by the Brazilian population

ABSTRACT

This study estimated the theoretical maximum daily intake (TMDI) of Sunset Yellow (SY) synthetic food dye by the Brazilian population through food consumption data from the Household Budget Survey (HBS) of the Brazilian Institute of Geography and Statistics (IBGE, 2008/09). The study covered the population in urban and rural areas in the five regions of the country, and from different age groups, in order to verify if it were possible to exceed the acceptable daily intake (ADI) of SY, which is 4.0 mg kg^–1 body weight. This was assessed by cross-checking food products containing this dye from the largest supermarket chains in Brazil with data from the HBS-IBGE 2008/09. These data showed that the average consumption of SY per capita did not exceed the ADI in any of the aforementioned population groups. However, when considering food consumption in urban and rural areas (279 and 260 mg of SY day^–1), in the five regions of the country (260–338 mg of SY day^–1), and for adolescents (332 mg SY day^–1), it is noted that part of the population could be exceeding the recommended ADI, which may pose health risks. Although it is unlikely that individuals will exceed the SY ADI, this may occur in some cases, especially for younger people.     

The use of inductively coupled plasma mass spectrometry (ICP-MS) for the determination of toxic and essential elements in different types of food samples

This paper describes a simple method for the determination of sixteen elements in food samples by using inductively coupled plasma spectrometry (ICP-MS). Prior to analysis, 100–250 mg of powdered food samples were accurately weighed into a Teflon digestion vessel. Then, 4 ml of 20% v/v concentrated nitric acid and 2 ml of hydrogen peroxide were added. Decomposition of samples was carried out in a microwave digestion system. In order to verify the accuracy and precision of the proposed method, five Standard Reference Materials from the National Institute of Standards and Technology (NIST) (Whole Egg Powder RM 8415, Rice Flour SRM 1568a, Typical Diet SRM 1548a, Wheat Flour SRM 1567a and Bovine Muscle Powder RM 8414) were analyzed. Additional validation data are provided based on the analysis of 18 different types of food samples by the proposed method and using comparative methods with AAS as the detector.     

A highly sensitive method for simultaneous determination of ultra trace levels of copper and cadmium in food and water samples with luminol as a chelating agent by adsorptive stripping voltammetry

In the present study a selective method is presented for the simultaneous determination of copper and cadmium in food samples by adsorptive stripping voltammetry. In preliminary studies, it has been proven that the copper and cadmium react with 3-aminophthalhydrazide (luminol), giving rise to the formation of these complexes. These complexes have adsorptive characteristics on hanging mercury drop electrode (HMDE) and can be reduced in a reduction step. In this study the optimum reaction parameters and conditions studies are investigated. The calibration graphs were linear in the concentration range of 0.5–105.0 and 0.8–70.0 ng/ml for copper and cadmium, respectively. The limit of detection of the method was 0.04 ng/ml for Cu²⁺ and 0.02 ng/ml for Cd²⁺. The interference of some common ions was studied and it was concluded that application of this method for the determination of copper (II) and cadmium in food and water samples led to satisfactory results.     

Separation and pre-concentration of Sunset Yellow in beverages and effervescent vitamin C tablets by a new flotation technique prior to spectrophotometric determination

ABSTRACT

A new, simple, low cost, high efficiency, and rapid floating technique was developed for the determination of Sunset Yellow in beverage and effervescent vitamin C. The method is based on two main steps: 1)- formation of dye-surfactant complex by the addition of a cationic surfactant, cetyltrimethylammonium bromide, to the solution containing an anionic dye (Sunset Yellow) and 2)- flocculation of the dye-surfactant complex with the participation of sodium perchlorate as a coagulant followed by aggregation and enlargement of the flocs while floating at the top of the solution. After the extraction, separated and preconcentrated Sunset Yellow was investigated by spectrophotometric determination. IR spectrum, scanning electron microscopy (SEM), and light microscopy were used to characterise the flocs. The effects of different parameters such as pH, concentration of surfactant, concentration of sodium perchlorate, and temperature on the extraction of dye were investigated and optimized. Under optimum conditions, a linear calibration curve was obtained in the range of 0.05–5 mg L^?1. The detection limit (3S_b/m) was 0.02 mg L^?1 with a preconcentration factor of 25. The relative standard deviation (RSD) for 0.1 mg L^?1 of Sunset Yellow was 2.6% (n = 10). The applicability of the method was evaluated by measuring the amount of dye in beverage and effervescent vitamin C. Interferences of typical cations and anions which may participate in the matrices were also checked. The amount of Sunset Yellow found in real samples was 1.32–3.89 mgL^?1.     

Generation of aniline from a subsidiary colour of Food Yellow No. 5 (Sunset Yellow FCF)

The formation of aniline from sodium salt of 6-hydroxy-5-(phenylazo)-2-naphthalenesulphonic acid (SS-AN, C.I. 15970, Orange RN), a subsidiary colour in the Japanese colour additive Food Yellow No.5 (Y-5, C.I. 15985, Sunset Yellow FCF), was investigated in the artificial gastric fluid (AGF) and in the artificial intestinal fluid (AIF) as prescribed in the degradation test in the Japanese Pharmacopoeia (1996). Aniline concentrations of 0.3-6.8 mu g/ml were found in 0.1% SS-AN solutions with 0.1-5.0% ascorbic acid or erythorbic acid after 24h at 37°C. This simulates a mixture of dye and ascorbic acid that might be ingested. The amount of aniline generated depended upon the temperature in these systems. In systems to which sucrose had been added, an increase in the amount of aniline generated was observed. However, no aniline generation was observed in the 0.1% SS-AN solutions in the AGF or AIF at 37°C for 24 h. Furthermore, the generation of aniline was not seen in AGF and AIF at higher temperatures in the range of 37-80°C. It was not generated by the degradation of SS-AN in the presence of digestive enzymes.     

Kinetic-spectrophotometry method for determination of ultra trace amounts of aluminum in food samples

A simple and sensitive kinetic-spectrophotometry method is developed for the determination of trace amounts of aluminum in food samples based on its catalytic effect on the oxidation of Nile Blue A by potassium bromate in sulfuric acid medium. The absorbance is measured at 595.5 nm with the fixed-time method. The optimization of the operating conditions regarding concentrations of the reagents, temperature and interferences are also investigated. The calibration curve is linear over the concentration range 0.07–0.9 μg ml⁻¹ of aluminum with good precision and accuracy and the detection limit was down to 0.034 μg ml⁻¹. The relative standard deviation for a standard solution of 0.4 μg ml⁻¹ of aluminum is 1.73% (n = 10). The proposed method proved highly sensitive, selective and relatively rapid for the assay of aluminum at ultra trace level without any pre-concentration and separation step. The method was applied to the determination of aluminum in food samples (rice, tea and potato). The analytical results of the real samples were in good agreement with the standard method.     

Sequential fluorescent determination of copper (II) and cobalt (II) in food samples by flow injection analysis

Copper (II) can react with a new fluorescence reagent, 5-(4-chlorophenylazo)-8-aminoquinoline (APAQCL), forming a fluorescence product only in slightly acidic medium, while the fluorescence product of cobalt (II) with APAQCL forms only in basic medium and in the presence of H₂O₂. Based on the difference of the reaction between cobalt (II) and copper (II) with APAQCL, a new flow injection method for the sequential determination of cobalt and copper in binary mixtures by use of a fluorimetric detector and APAQCL as reagent was proposed. Linear calibration graphs were obtained over the concentration range 0.010–1.20 (μg/ml) of cobalt (II) and 0.050–5.00 (μg/ml) of copper (II) with the detection limit of 0.0030 (μg/ml) of cobalt (II) and 0.010 (μg/ml) of copper (II), respectively. The applicability of the method to the sequential determination of cobalt (II) and copper (II) in food samples was demonstrated by investigating the potential interference and by the analysis of synthetic mixtures of copper (II) and cobalt (II). The method was successfully applied to the determination of copper and cobalt in food samples.     

Selective cloud point extraction for the determination of cadmium in food samples by flame atomic absorption spectrometry

A new cloud point extraction (CPE) procedure for preconcentration of cadmium prior to the determination by flame atomic absorption spectrometry (FAAS) was developed. The method is based on the fact that cadmium could form hydrophobic ion-associated complex in the presence of iodide and methyl green (MG), and the hydrophobic ion-associated complex could be extracted into surfactant-rich phase. The main factors affecting CPE procedure, such as pH, concentration of KI, MG and surfactant, equilibrium temperature and incubation time, sample volume were investigated. Potential interference from co-existing ions was largely eliminated as most of co-existing ions can not form extractable ion-associated complex with iodide and MG. Under the optimum conditions, the limit of detection (3σ) and limit of quantity (10σ) were 0.90 ng mL⁻¹ and 3.0 ng mL⁻¹ for cadmium, respectively, and relative standard deviation was 4.2% (c = 50 ng mL⁻¹, n = 7). The proposed method was successfully applied to determination of cadmium in the certified reference rice sample (GBW08510) and food samples with satisfactory results.     

原子吸收光谱法检测含乳饮料中铜的不确定度评定

目的对原子吸收光谱法检测含乳饮料中铜元素含量的不确定度进行评定。方法从测量重复性、校准曲线等方面分析该方法的不确定度来源,依据GB/T 5009.13-2003《食品中铜的测定》建立数学模型,根据JJF 1059.1-2012《测量不确定度的评定与表示》对测量结果的各不确定度来源进行分析和量化。结果当含乳饮料中铜含量为0.29 mg/L时,其扩展不确定度为0.022 mg/L(k=2)。不确定度主要来源于试样测定时标准曲线使用玻璃量具的引入,其次是测量重复性引入的不确定度。结论本研究可为原子吸收法测定含乳饮料中铜含量的测量准确性提供参考。     

Application of an enzyme immunoassay for the quantitative determination of azo dye (Orange II) in food products

This paper reports the preparation of polyclonal antibodies against a synthetic azo dye, Orange II, and the development of an indirect ELISA to detect Orange II in foods. The sulfonic group of Orange II was modified and linked with carrier protein to synthesise an artificial antigen. Based on the checkerboard titration, the method showed excellent sensitivity (IC₅₀?=?0.61 ng?g^?1) to Orange II in the linear range of 0.05–10?ng?g^?1. The antibody had little cross-reactivity with Chromotrope FB, Gardenia Yellow, Ponceau 4R, Sunset Yellow and Sudan dyes. The ELISA had limits of detection (LOD) of 0.22, 0.97 and 0.74?ng?g^?1 in chilli powder, chilli oil and braised pork, respectively. The limits of quantification (LOQ) of the assay were 0.91?ng?g^?1 in chilli powder, 1.48?ng?g^?1 in chilli oil and 1.10?ng?g^?1 in braised pork. For food products fortified with 1–10?ng?g^?1 Orange II, the inter- and intra-assay variations were all less than 24.0% and 18.0%, respectively. Therefore, the proposed test could be used as a rapid screening method for Orange II detection in food samples.     

食品快速检测方法在国内外的应用与管理比较

食品快速检测因其简便、价格低廉等特点广泛用于食品的快速筛查和现场检测,是基层食品安全监管的技术支撑。本研究整理了食品快速检测方法的发布情况,对比分析了食品快速检测方法在国内外食品安全监管中的应用现状与管理模式,并对现阶段存在的主要问题进行了深入剖析,并提出建议。     

反式脂肪酸检测方法研究与应用

研究了甲醇钠-甲醇、氢氧化钾-甲醇、浓硫酸-甲醇和三氟化硼-甲醇4种甲酯化试剂的浓度、用量及甲酯化时间和温度对反式脂肪酸检测的影响,优化了色谱条件,建立了以三氟化硼-甲醇法甲酯化,RT-2560（100m×0．25mm×0．2μm）毛细管柱为基础的反式脂肪酸气相色谱检测方法,C18：1—9t,C18：1—11t,C18：2—9t,12t和C22：1—13t 4种反式脂肪酸的最小检出浓度在0．77—4．08mg／kg之间。4种反式脂肪酸不同添标浓度回收率为98．44％-101．23％,重复测定的相对标准差在0．22％-1．31％之间,有较好的准确度和重现性。应用该方法检测了武汉部分小型市场散装食用植物油和-些餐馆的废弃油脂,以所含脂肪为基准,其反式脂肪酸含量分别为：0．12％-0．25％、3．63％-6．58％。表明天然食用植物油中反式脂肪酸含量较低,但油脂在高温加工过程中会产生反式脂肪酸。     

特医食品中植物源新食品原料测定方法研究进展

近年来,随着各国慢性病患者数量的急剧增加及人口老龄化程度的加深,普通食品已不能满足这些人群的营养需求,特殊医学用途配方食品(food for special medical purpose,FSMP)应运而生并逐渐成为医护系统和消费者的关注热点.开发和深入研究FSMP是未来食品发展的新方向,FSMP中原料和成分检测方法...     

Simultaneous and rapid determination of added phosphorus(V) compounds in meat samples by capillary isotachophoresis

One-dimensional capillary isotachophoretic method (CITP) for the simultaneous determination of added phosphorus(V) compounds (ortho-, pyro- and tripolyphosphates) in pork meat is described. The calibration curves were obtained for KH₂PO_4, K₄P₂O₇, Na₂H₂P₂O₇, Na₃P₃O_9, Na₅P₃O₁₀ resulting in linearity (R² = 0.9996, 0.9998, 0.9991, 0.9978 and 0.9994, respectively). Detection limits ranged from 0.4 mg P/L for potassium pyrophosphate (PP) to 1.1 mg P/L for trisodium trimetaphosphate (TTP) and quantification limits ranged from 1.2 mg P/L for PP to 3.7 mg P/L for TTP. The repeatabilities of within-day and between-days analysis were ≤2.27% and ≤4.89% for relative step height, respectively. The developed procedure was applied for added phosphates determination in meat samples. The minimal sample pretreatment and presented results make CITP an alternative to the existing methods of meat analysis.     

微生物法测定全营养配方食品中生物素的不确定度评定

目的 探讨并建立全营养配方食品中生物素的测量不确定度及评定方法。方法 依据《GB 5009.259-2016 食品中生物素的测定》和《JJF 1059.1-2012 测量不确定度评定与表示》以及相关统计学方法,对影响全营养配方食品中生物素含量结果的不确定度分量进行探究和评定。结果 采用微生物法,对同一样品的生物素含量进行6次测定,生物素含量的扩展不确定度为1.84 μg /100g,k=2。通过研究发现测量重复性和标准物质称量及标准溶液配制过程是影响检测结果的主要因素,试样系列管制备过程、标准曲线拟合和、紫外分光光度计的偏差和样液制备过程为次要因素,天平的称量误差对不确定度的影响不显著。 结论 该方法准确、全面,对全营养配方食品中生物素测定结果的不确定度作出较好的评估,可配合实际应用中全营养配方食品生物素的不确定度评定。     

Electrochemical sensor based on graphene and mesoporous TiO2 for the simultaneous determination of trace colourants in food

Currently, synthetic colourants draw much attention as food additives. This paper investigated the simultaneous electrocatalytic oxidation of sunset yellow and tartrazine, two yellow colourants commonly present in food together, with a novel voltammetric sensor based on graphene and mesoporous TiO₂ modified carbon paste electrode. Due to the high accumulation effect and great catalytic capability of graphene and mesoporous TiO₂, the developed sensor exhibited well-defined and separate square wave voltammetric peaks (i.e., 272 mV) for sunset yellow tartrazine. The peak currents of sunset yellow and tartrazine increased linearly with their concentration in the ranges of 0.02–2.05 μM and 0.02–1.18 μM, respectively. And the detection limit was 6.0 and 8.0 nM for sunset yellow and tartrazine, respectively. This new sensor was applied to determine sunset yellow and tartrazine in several food sample extracts. Results suggested that the proposed sensor was sensitive, rapid and reliable.