微波消解-连续流动分析法测定肉类食品中的磷

肉类食品是重要的磷来源,随着磷酸盐在肉制品生产加工中的广泛应用,它在食品中的安全性也备受关注。因此,建立一种肉类食品中磷快速定量测定方法具有重要意义。本研究重点优化了肉类样品的微波消解体系,并在此基础上建了肉类样品磷含量检测的微波消解-连续流动分析法。研究结果表明,硝酸可以作为微波消解酸体系,并且硝酸用量为6 mL、样品量0.1g、赶酸温度210℃和消解液稀释倍数100倍时,为较优的微波消解条件。微波消解处理后的样品利用连续流动分析仪进行外标法定量检测。测定结果表明,本研究建立的微波消解-连续流动分析法的检测线性范围为0~4 mg/L,线性相关系数为0.9994,样品回收率为92.5%~103%,精密度RSD小于5%（n=10）。本研究建立的方法适用于肉类食品中磷的快速、批量检测。     

多道检测—激光诱导荧光猝灭法测定食品中磷

利用激光诱导荧光 二极管阵列检测 计算机联用装置 ,对磷钼杂多酸 罗丹明 6G荧光猝灭体系进行了研究 ,建立了一种测定食品中磷的新荧光光度法。试验表明 ,该法具有较好的灵敏度、选择性 ,检出限为 0 .1ng·ml- 1,加标回收率为 90 .6%～ 10 9.0 % ,相对标准偏差为 1.3%～3 0 % ,用于食品样品中磷的测定 ,结果满意     

氧弹燃烧-分光光度法测定豆类中的磷

豆类是人类三大食用作物之一,具有非常高的营养价值和生理功能,其中的功能成分具有很高的食疗作用。随着动物性食品引起的富贵病的出现,食用豆类的营养特性和功能特性引起了人们的极大关注[1]。磷作为人类必需的营养成分,参与人体骨骼和牙齿的构成,同时参与脂肪、蛋白质、糖类的代谢,几乎所有食品中都含磷。豆类中的磷大多以植酸磷形式存在,有机物中磷的测定方法有钼蓝、钼黄分光光度法,前者检出限低,灵敏度高,适用于检测磷含量较低的食品;后者     

检测磷的一种简便方法

关于磷的测定,无论是工农业、冶金、医药和食品等分析,还是基础教学中都是很重要的工作。迄今,运用最广泛而最经典的方法仍是磷钼蓝法检测磷。但是该法还存在某些问题:反应需在加热条件下进行;钼蓝的显色对体系的酸碱度要求严格;硅酸根离子干扰。针对上述不足,笔者在试验中摸索出一种灵敏度高、选择性好、快速、简便的检测磷的方法。并已用于实样分析和教学中,效果满意。     

食用明胶中猪源性成分检测研究进展

明胶是一种重要的食品添加剂,主要来源于猪、牛等动物的骨和皮.在伊斯兰教的宗教信仰中,禁止食用含有猪源性成分的产品,因此对于食用明胶中猪源性成分的检测至关重要.该文主要对近年来国内外有关明胶中猪源性DNA或蛋白质成分的检测方法及优缺点进行了阐述分析,并对未来检测方法的发展趋势进行了展望.由于食品在加工过程中会发生DNA和...     

钒—钼酸铵比色法测定食品中总磷

食品中的磷具有营养学意义.常用的定量方法有钼蓝比色法和重量法,钼蓝比色法测定食品中的总磷,酸度对测定结果的影响比较大,方法的重现性差;重量法仅适用于磷的含量较高的食品.本文参照文献,用钒-钼酸铵比色法测定食品中总磷,试液酸度对吸光度几乎没有影响,磷含量在0.5～10mg·L~(-1)范围内呈良好的线性关系,相关系数r=0.9998,相对标准偏差<3%,加标回收率在97.6%～103.7%之间.     

微波灰化-电感耦合等离子体发射光谱法测定婴幼儿乳粉中的钙和磷

采用微波灰化-电感耦合等离子体发射光谱法（ICP-OES）测定婴幼儿乳粉中钙、磷元素含量.采用微波灰化法对婴幼儿乳粉进行前处理,正交试验方法确定微波灰化最佳条件,灰化后产物用2 mL硝酸溶液(体积比为1∶1)溶解后,用ICP-OES对钙、磷元素进行含量检测.磷加标回收率为86%～104%,钙加标回收率为87%～96%.磷的相对标准偏差为2.5%～7.0%,钙的相对标准偏差为3.9%～10.0%,能够满足日常检测要求.采用微波灰化法对婴幼儿乳粉中钙、磷元素进行样品前处理,相比微波消解方法,具有用时短、用酸量少、消解效果好、不需要进行赶酸处理等优点.与干法灰化和湿法消解相比大大减少了样品处理时间.采用微波灰化与ICP-OES结合对婴幼儿乳粉中的重要指标元素进行检测,在婴幼儿乳粉质量控制中有很好的应用价值.     

食品中甜味剂的检测技术研究进展

食品中甜味剂对人体健康有重要影响,因此日益受到人们的关注,需要建立针对食品中甜味剂的检测方法。对2008年以来食品中甜味剂的检测方法液相色谱、液相色谱–质谱、气相色谱–质谱、光谱等分析方法进展进行了综述。     

加速溶剂萃取-凝胶渗透色谱净化-气相色谱快速分析动物源性食品中残留的多种有机磷农药

建立了动物源性食品猪肉、牛肉、鸡肉及鱼肉中36种有机磷农药残留的快速分析方法。以乙腈作为溶剂,对试样采用加速溶剂萃取仪萃取,自动凝胶渗透色谱仪净化预处理,N-丙基乙二胺(PSA)填料再净化,毛细管气相色谱法分离,火焰光度检测器(磷型)检测,内标法定量。该方法分离效果良好,重现性好,灵敏度、精密度高,杂质干扰少。36种有机磷农药的检测限(LOD)为0.0012 mg/kg(乙拌磷)～0.014 mg/kg(吡唑硫磷),定量限(LOQ)为0.004 mg/kg(乙拌磷)～0.047 mg/kg(吡唑硫磷)。当试样中有机磷农药的添加浓度分别为0.05,0.1,0.2 mg/kg时,回收率为58.2%～106.3%。方法的最低检测限和添加回收率均符合农药残留分析的要求。     

顶空固相微萃取-气相色谱法测定粉状大豆磷脂的丙酮残留

固相微萃取技术(SPME)作为一种样品预处理方法已在食品溶剂残留检测中得到了广泛的应用。大豆磷脂是一种保健品,广泛地应用在食品与医药领域。在我国．粉状大豆磷脂在加工过程中采用丙酮提取杂质。磷脂中丙酮残留不利于人体健康。目前,我国粉状磷酯产品尚无统一的测定方法和溶剂残留标准,大多生产厂家需借鉴国外的     

Liquid scintillation method for determination of solvent-extracted phosphorus-32 in foods

A method for solvent extraction of radioactive phosphorus as phospho-molybdic acid in foods is described. The use of a carrier can be eliminated due to the quantity of the stable element present in foods. The use of a liquid scintillation technique for counting is discussed, showing the effective elimination of color and chemical quench. The efficiency resulting from the liquid scintillation method of counting makes possible the detection of 10^-5 μc levels of activity in the original sample.     

Need for accurate and standardized determination of amino acids and bioactive peptides for evaluating protein quality and potential health effects of foods and dietary supplements

Accurate standardized methods for the determination of amino acid in foods are required to assess the nutritional safety and compositional adequacy of sole source foods such as infant formulas and enteral nutritionals, and protein and amino acid supplements and their hydrolysates, and to assess protein claims of foods. Protein digestibility-corrected amino acid score (PDCAAS), which requires information on amino acid composition, is the official method for assessing protein claims of foods and supplements sold in the United States. PDCAAS has also been adopted internationally as the most suitable method for routine evaluation of protein quality of foods by the Food and Agriculture Organization/World Health Organization. Standardized methods for analysis of amino acids by ion-exchange chromatography have been developed. However, there is a need to develop validated methods of amino acid analysis in foods using liquid chromatographic techniques, which have replaced ion-exchange methods for quantifying amino acids in most laboratories. Bioactive peptides from animal and plant proteins have been found to potentially impact human health. A wide range of physiological effects, including blood pressure-lowering effects, cholesterol-lowering ability, antithrombotic effects, enhancement of mineral absorption, and immunomodulatory effects have been described for bioactive peptides. There is considerable commercial interest in developing functional foods containing bioactive peptides. There is also a need to develop accurate standardized methods for the characterization (amino acid sequencing) and quantification of bioactive peptides and to carry out dose-response studies in animal models and clinical trials to assess safety, potential allergenicity, potential intolerance, and efficacy of bioactive peptides. Information from these studies is needed for determining the upper safe levels of bioactive peptides and as the basis for developing potential health claims for bioactive peptides. This information is, in turn, needed by regulatory agencies for developing appropriate policy and regulations on adding these substances to foods and for determining if health claims are scientifically substantiated.     

食品中维生素D与25-羟基维生素D检测技术及含量分布研究进展

维生素D是一种对于维持人体健康具有重要作用的脂溶性维生素,25-羟基维生素D是其在人体内循环和存储的主要形式。食品中维生素D和25-羟基维生素D前处理的通常采用碱皂化、有机溶剂提取、固相萃取或者半制备色谱净化;其测定方法多为放射免疫法和液相色谱法。液相色谱串联质谱凭借高灵敏度和高准确度,目前在食品中维生素D和25-羟基维生素D测定中发挥重要作用。近年来二维液相色谱和超高效超临界流体色谱由于其强大的分离能力,在食品中维生素D和25-羟基维生素D的分析中表现出强大的潜力。该文综述了近年来食品中维生素D和25-羟基维生素D的检测方法及二者在动物食品和植物食品中的含量分布研究,以期为建立适合不同食物样品的测定方法,指导居民合理膳食,进行膳食摄入量评估等研究工作提供参考。     

Determination of phosphorus in fertilizers by inductively coupled plasma atomic emission spectrometry

An inductively coupled plasma atomic emission spectrometry (ICP-AES) method was developed for the determination of phosphorus in fertilizers. Total phosphorus, direct extraction available phosphorus (EDTA), and water-soluble phosphorus, reported as phosphorus pentoxide (P205), in 15 Magruder check fertilizers were measured by ICP-AES, and the results were compared with those obtained by the AOAC official method. Five analytical wavelengths of phosphorus, 177.499, 178.287, 213.618, 214.914, and 253.565 nm, were tested for the determination of phosphorus in fertilizers, and their detection limits were obtained. Acid effects of perchloric acid and possible matrix effects of aluminum, calcium, magnesium, potassium, and sodium were negligible for phosphorus determination. Wavelength 213.618 nm was the best analytical wavelength for phosphorus determination by all 3 sample preparation methods for the selected Magruder fertilizers. The results demonstrated that the accuracy and precision of the ICP-AES method were comparable with those of the official methods.     

Chromatographic determination of amino acids in foods

Amino acids in foods exist in a free form or bound in peptides, proteins, or nonpeptide bonded polymers. Naturally occurring L-amino acids are required for protein synthesis and are precursors for essential molecules, such as co-enzymes and nucleic acids. Nonprotein amino acids may also occur in animal tissues as metabolic intermediates or have other important functions. The development of bacterially derived food proteins, genetically modified foods, and new methods of food processing; the production of amino acids for food fortification; and the introduction of new plant food sources have meant that protein amino acids and amino acid enantiomers in foods can have both nutritional and safety implications for humans. There is, therefore, a need for the rapid and accurate determination of amino acids in foods. Determination of the total amino acid content of foods requires protein hydrolysis by various means that must take into account variations in stability of individual amino acids and resistance of different peptide bonds to the hydrolysis procedures. Modern methods for separation and quantitation of free amino acids either before or after protein hydrolysis include ion exchange chromatography, high performance liquid chromatography (LC), gas chromatography, and capillary electrophoresis. Chemical derivatization of amino acids may be required to change them into forms amenable to separation by the various chromatographic methods or to create derivatives with properties, such as fluorescence, that improve their detection. Official methods for hydrolysis and analysis of amino acids in foods for nutritional purposes have been established. LC is currently the most widely used analytical technique, although there is a need for collaborative testing of methods available. Newer developments in chromatographic methodology and detector technology have reduced sample and reagent requirements and improved identification, resolution, and sensitivity of amino acid analyses of food samples.     

环境水样中总磷分析方法及仪器的研究进展

磷是生物不可或缺的营养元素之一,但由于人类活动影响,在地表水和近岸海水中总磷一直是主要污染指标。总磷测定通常分两步进行：一是将水样中各种不同形态的磷消解转化为可被检测的磷酸盐;二是测定消解后样品中的磷酸盐浓度。消解方法有硫酸-硝酸消解法、干法灰化法、微波辅助消解法、过硫酸钾-高温高压消解法、UV光氧化法等。测定方法包括电化学法、化学发光法、磷钼蓝分光光度法、磷钒钼黄分光光度法等。目前应用最为广泛的是过硫酸钾-高温高压消解法和磷钼蓝分光光度法。总磷测定仪器通常基于该消解法和测定法而开发,可分为用于实验室的水样离线分析仪和用于水体现场的在线分析仪两类。该综述总结了近20年来环境水样中上述总磷分析方法及仪器的研究进展,比较了各方法和仪器的特点,并分析了总磷分析方法和分析仪器的发展趋势。     

Determination of aflatoxins in food by overpressured-layer chromatography

Legislative measures for monitoring and control of aflatoxin levels in foods and foodstuffs have been introduced in many countries. The aim of the present work was to make developments in the field of aflatoxin analysis, focusing upon the use of overpressured-layer chromatography (OPLC) for quantitative determination. OPLC methods have been developed for the determination of aflatoxins B1, B2, G1, G2 in different foods. These methods are suitable for sample clean-up and separation as well. Using OPLC we could analyze 10 samples simultaneously. The methods were investigated with fish, corn and wheat samples spiked with 2-10 ng/g aflatoxins. Quantitative evaluation of aflatoxins was accomplished by densitometry. Average recoveries from each food were greater than 73%. The OPLC technique seems to be a rapid, reproducible and cost-effective analysis for quantitative determination of aflatoxins in foods.     

Analysis of red phosphorus in resins using pyrolysis-gas chromatography/mass spectrometry.

Although red phosphorus is used as a flame retardant for polymer materials, no analysis methods for it in resins has been established. Analysis methods for red phosphorus in resins were investigated using pyrolysis-gas chromatograpy/mass spectrometry (Py-GC/MS) by paying attention to the fact that it has a sublimation property. We found that the mass spectrum of red phosphorus shows a series of ions at m/z=62, 93 and 124, and a fragment pattern indicating that red phosphorus (P4=124, P=31) was pyrolytically decomposed. The coefficient of the correlation between the content of red phosphorus in the resin and the peak intensity in Py-GC/MS was 0.9781. The relative standard deviations of this analysis method was 6.29% (n=5). Py-GC/MS was applicable not only to qualitative analysis but also to the quantitative analysis of red phosphorus.     

Evaluation of VIDAS Immuno-Concentration Salmonella (ICS)/VIDAS Salmonella (SLM) immunoassay method for detection of Salmonella in selected foods (Method Modification 2001.09): collaborative study

A new method for detection of Salmonella in foods in a minimum of 24 h was adopted as an AOAC Official First Action Method for selected foods (2001.09) using both the VIDAS Immuno-Concentration Salmonella (ICS) and VIDAS Salmonella (SLM) methods.     

Determination of polydextrose as dietary fiber in foods

Polydextrose (Litesse) provides physiological effects consistent with dietary fiber. However, AOAC methods for measuring total dietary fiber (TDF) in foods include an ethanol precipitation step in which polydextrose and similar carbohydrates are discarded and therefore not quantitated. This study describes a method developed to quantitate polydextrose in foods. The new method includes water extraction, centrifugal ultrafiltration, multienzyme hydrolysis, and anion exchange chromatography with electrochemical detection. Six foods were prepared with 4 levels of polydextrose to test the ruggedness of the method. Internal validation demonstrated the ruggedness of the method with recoveries ranging from 83 to 104% with an average of 95% (n = 24) and relative standard deviation of recoveries ranging from 0.7 to 13% with an average of 3.3% (n = 24). The value is added to that obtained for dietary fiber content of foods using the AOAC methods, to determine the TDF content of the food.