牛乳中硝酸盐,亚硝酸盐的快速定性分析

牛乳中硝酸盐、亚硝酸盐的快速定性分析齐齐哈尔华齐乳品厂苏朝文，赵以明近年来，乳粉中硝酸盐、亚硝酸盐含量指标越来越受到人们的高度重视，而原料乳中硝酸盐、亚硝酸盐含量的高低，直接影响产成品的质量。如何找到一种快速、简便、准确的测定原料乳中硝酸盐、亚硝酸盐...     

几种叶菜储藏中硝酸盐、亚硝酸盐含量及硝酸盐还原酶活性研究

对小白菜,大白菜、包菜、菠菜等4种蔬菜在室温储藏过程中硝酸盐、亚硝酸盐含量及硝酸盐还原酶活力进行分析。结果表明,储藏前后小白菜NO-3含量均超出国家标准;储藏3d后小白菜和菠菜中NO-2含量超标,该2种菜不适宜储存后食用。对4种叶菜储藏中NRA进行检测,其变化无一定规律。对4种蔬菜储藏3d内的NO-3含量的降解速率及其相应的NRA进行分析,4种蔬菜NO-含量的变化与NRA变化未呈现一定相关性。      

几种叶菜储藏中硝酸盐、亚硝酸盐含量及硝酸盐还原酶活性研究

对小白菜,大白菜、包菜、菠菜等4种蔬菜在室温储藏过程中硝酸盐、亚硝酸盐含量及硝酸盐还原酶活力进行分析。结果表明,储藏前后小白菜NO-3含量均超出国家标准;储藏3d后小白菜和菠菜中NO-2含量超标,该2种菜不适宜储存后食用。对4种叶菜储藏中NRA进行检测,其变化无一定规律。对4种蔬菜储藏3d内的NO-3含量的降解速率及其相应的NRA进行分析,4种蔬菜NO-含量的变化与NRA变化未呈现一定相关性。     

几种常见野菜中硝酸盐和亚硝酸盐含量

几种常见野菜中硝酸盐和亚硝酸盐含量韩涛，马红梅，李丽萍，黄万荣北京农学院食品科学系１０２２０８近年来，野生蔬菜因其营养、保健、无污染等优点日益受到人们的关注。杨恩孚等人［１］曾具体分析过７２种野菜中的维生素含量，其中胡萝卜素的含量只有７种低于胡萝卜；...     

食品添加剂硝酸盐、亚硝酸盐检测方法研究进展

硝酸盐、亚硝酸盐主要用作防腐剂与着色剂应用于食品加工生产过程中,但有研究显示过量摄入可能引起中毒或死亡,对其检测方法的研究也处于不断摸索优化阶段。本文主要对硝酸盐与亚硝酸盐的检测方法研究进展进行了综述,并对相关检测方法进行对比介绍。目前,应用较多的检测方法有快速检测法、分光光度法、化学发光法、电化学方法、高效液相色谱法等。其中,快速检测法耗时较短,但不能实现对硝酸盐和亚硝酸盐的准确定量;而光谱法在一定程度上解决定量问题,但该方法检测限普遍较高;电化学方法操作简便,但存在一定的不确定性;众多研究数据显示,色谱法具有操作简单、快速、灵敏度高等特点,在众多领域应用最为广泛,尤其高效液相色谱法最为突出。气相色谱法在其基础上可实现硝酸盐与亚硝酸盐的同时检测。本文也对高效液相色谱法进行重点介绍。     

蔬菜中硝酸盐与亚硝酸盐检测方法的研究进展

综述了亚硝酸盐和硝酸盐的检测方法,指出了各检测方法的优劣及其应用前景,对于监控蔬菜生产加工中硝酸盐和亚硝酸盐的含量,检测蔬菜产品的品质等具有参考意义。     

蔬菜中硝酸盐和亚硝酸盐的污染

综述了硝酸盐和亚硝酸盐的危害、污染来源、蔬菜中的污染现状、蔬菜中硝酸盐积累机理及控制措施。     

蔬菜中硝酸盐和亚硝酸盐检测方法的研究进展

硝酸盐和亚硝酸盐主要通过蔬菜食用进入人体,亚硝酸盐是一种有毒物质,人食用后会在体内产生致癌性 的亚硝胺。光谱法、色谱法、快速检测法是目前检测蔬菜中硝酸盐和亚硝酸盐的主要方法。本文在对上述方法进行 介绍并比较的基础上,对蔬菜中硝酸盐和亚硝酸盐检测方法的研究进展进行了概述与展望。     

离子色谱法检测水产品中的硝酸盐与亚硝酸盐

利用免试剂离子色谱法建立测定水产品中硝酸盐和亚硝酸盐的检测方法。样品经搅碎,超声提取,75～80℃水浴加热,离心,减压过滤,再经OnGuardⅡRP柱除去微量的蛋白质和脂肪,稀释,0.22μm水系膜过滤器过滤后,进离子色谱系统。经KOH等浓度淋洗(KOH浓度为15 mmol/L,抑制电流为38 mA,流速为1 mL/min),IonPac AG11-HC(4 mm×50 mm)保护柱,IonPac AS11-HC(4 mm×250 mm)分离柱分离后,用抑制型电导检测器检测。本方法的相关性好,NO3-的相关系数为0.99914,NO2-的相关系数为0.99952,NO3-的检出限为0.0277 mg/kg,NO2-的检出限为0.0186 mg/kg。鲈鱼中这两种离子的加标回收率在60%～81%之间,RSD在5%内。本方法方便、快捷、安全,操作简便,对多种样品适应性好。     

蔬菜中硝酸盐、亚硝酸盐提取与测定的研究

目的:研究蔬菜中硝酸盐、亚硝酸盐对保障人类健康具有重要意义.方法:本实验选择用简便、高效的超声波提取技术提取蔬菜中的硝酸盐和亚硝酸盐,用紫外分光光度法测定其含量.结果:研究表明,利用紫外分光光度法同时测定蔬菜中硝酸盐和亚硝酸盐含量的方法简单、快速、选择性好.结论:硝酸盐测定的相对误差在-2.52％～1.14％之间,亚硝酸盐测定的相对误差在1.98％～4.26％之间,符合定量测定要求.     

Nitrate and nitrite content in organically cultivated vegetables

The nitrate and nitrite content of leaf vegetables (Swiss chard, sea beet, spinach and cabbage), “inflorescence” vegetables (cauliflower) and fruit vegetables (eggplant and vegetable marrow) grown with organic fertilizers have been determined by a modified cadmium–Griess method. Samples were purchased from organic food stores as well as collected directly from an organic farm in Madrid (Spain). Nitrate levels were much higher in the leaf vegetables (especially Swiss chard species; average over the different samples and species of 2778.6 ± 1474.7 mg kg^{? 1}) than in inflorescence or fruit products (mean values between 50.2 ± 52.6 and 183.9 ± 233.6 mg kg^{? 1}). Following Swiss chard species, spinach (1349.8 ± 1045.5 mg kg^{? 1}) showed the highest nitrate content, and nitrite was found above the limit of detection in some samples only (spinach, 4.6 ± 1.0 mg kg^{? 1}; sea beet, 4.2 ± 0.7 mg kg^{? 1} and Swiss chard, 1.2 ± 0.4 mg kg^{? 1}). Some vegetables (spinach, cabbage and eggplant) had lower nitrate content in the samples harvested in summer, showing the influence of climatic conditions on the nitrate levels in a plant. The samples taken directly from the organic farm, with the exception of eggplant, had higher or slightly higher average nitrate values than samples purchased in the organic food stores, ranging from 117 to 1077%.     

生乳中亚硝盐回收率检测分析研究

目的 改进国标中因生乳本底对回收率结果的影响。方法 依据GB 5009.33-2016《食品中亚硝酸盐与硝酸盐的测定》中第二法分光光度法, 在加标回收实验中将生乳本底进行不同倍数稀释, 确定回收率最佳时的稀释倍数。结果 对生乳本底进行稀释后, 确定10倍稀释后加标回收率全部符合要求, 最大相对标准偏差为9.118%。检测实际样品时, 本方法与国标检测结果经无显著性差异(P=0.10)。结论 改进后的方法操作简单, 回收率高、准确性高, 可用于牛乳中亚硝酸盐的检测。     

Nitrate and nitrite in fresh vegetables from queensland

Vegetables were collected near peak harvest from the main production regions in Queensland and were analysed for residues of nitrate and nitrite. A small sample of hydroponic produce was also included in the survey. Nitrite-N from 1 to 4 mg kg^-1 was found only in dwarf beans and in lettuces. Levels of nitrate in potatoes, cabbages and beets were higher than those reported in other surveys and exceeded threshold limits set in one other country. The median nitrate-N concentration measured in hydroponic lettuce (465 mg kg^-1 nitrate-N) was more than twice the median concentration for field-grown lettuce. Poor correlation between total N and nitrate in vegetables raises doubts about the use of total N alone as an indicator of N status.     

乳粉中亚硝酸盐检测质量控制图的应用

目的 建立乳粉中亚硝酸盐检测的质量控制图,判断检测过程与结果是否处于控制状态.方法 以有证标准样品作为控制样品,依据GB 5009.33—2016《食品安全国家标准食品中亚硝酸盐与硝酸盐的测定》检测控制样品中亚硝酸盐的含量.将子组数设为25,每个子组平行测定2次,利用Microsoft Office Excel软件,绘...     

Nitrate and nitrite levels in commonly consumed vegetables in Hong Kong

Levels of nitrate and nitrite in 73 different vegetables, a total of 708 individual samples grouped into leafy, legumes, root and tuber, and fruiting vegetables, which are traded mainly in Hong Kong, were measured. Where available, five samples of each vegetable type were purchased from different commercial outlets during the winter of 2008 and summer of 2009. Levels of nitrate and nitrite were determined by ion chromatography and flow injection analysis, respectively. Nitrate and nitrite levels of all samples ranged <4–6300 and <0.8–9.0 mg?kg^?1, respectively. Nitrate concentrations for the different groups, in descending order, were leafy?>?root and tuber?>?fruiting and legume vegetables. More than 80% of vegetables had mean nitrate concentrations less than 2000?mg?kg^?1, but mean nitrate concentrations of three types of leafy vegetables, namely Chinese spinach, Shanghai cabbage and Chinese white cabbage, were >3500?mg?kg^?1. On the other hand, nitrite concentrations were generally low –?<1?mg?kg^?1 on average. Nitrate in vegetables (i.e. Chinese flowering cabbage, Chinese spinach and celery) can be reduced significantly (12–31%) after blanching for 1–3?min, but not after soaking.     

商品奶与原料奶中农药与亚硝酸钠残留分析

采用高效气相色谱(GC)分析法对商品奶和原料奶中农药和亚硝酸钠残留进行分析,并分析不同饲养模式对原料奶中农药残留的影响。结果表明:在所测定的5种农药中,甲胺磷、敌敌畏和马拉硫磷等3种农药残留检出率较高,商品奶为45.0%～67.5%,原料奶为46.8%～71.2%。商品奶和原料奶中甲胺磷、敌敌畏、敌百虫、马拉硫磷和倍硫磷检出率和残留量差异不显著(P﹥0.05);而商品奶和原料奶中亚硝酸钠检出率和残留量差异极显著(P﹤0.01)。原料奶中5种农药加权平均检出率、农药加权平均残留量和加权残留总量均为规模化饲养显著低于农户散养和合作社饲养(P﹤0.05),后两者之间无显著差异(P﹥0.05)。     

衍生化-富集-表面增强拉曼光谱法快速筛查奶粉中亚硝酸盐

目的 建立衍生化-富集-表面增强拉曼光谱法快速检测奶粉中亚硝酸盐的分析方法。方法 样品水溶液通过除蛋白、衍生化后,采用阳离子小柱PSY-001对衍生化合物进行富集,再使用表面增强拉曼光谱对样品中的亚硝酸盐含量进行定性检测。结果 7类不同奶粉,采用本研究所建立的方法进行检测,根据不同的批处理量,单个样品检测全过程只需3~15 min,定性检测限为0.4 mg/kg,远低于国家安全标准对亚硝酸盐的限量要求(2 mg/kg)。方法的灵敏度在96%～100%,特异性为100%,假阴性率为0%～4%,假阳性率为0%,相对准确度为98%～100%。结论 该方法操作简单、快速,易于掌握,适用于奶粉中亚硝酸盐的快速筛查。     

Changes in nitrate and nitrite content of four vegetables during storage at refrigerated and ambient temperatures

The nitrate and nitrite contents of four kinds of vegetables (spinach, crown daisy, organic Chinese spinach and organic non-heading Chinese cabbage) in Taiwan were determined during storage at both refrigerated (5 ± 1°C) and ambient temperatures (22 ± 1°C) for 7 days. During storage at ambient temperature, nitrate levels in the vegetables dropped significantly from the third day while nitrite levels increased dramatically from the fourth day of storage. However, refrigerated storage did not lead to changes in nitrate and nitrite levels in the vegetables over 7 days.     

蔬菜中亚硝酸盐和硝酸盐检测技术研究进展

硝酸盐和亚硝酸盐广泛存在于人们的生活中,人体外源性硝酸盐的摄入大多来自蔬菜。硝酸盐对人体没有直接危害,但它可以在人体内的酶和微生物的作用下转化为有毒的亚硝酸盐,使血液的输氧能力下降,导致高铁血红高蛋白症。蔬菜在人们的日常膳食中占据重要的地位,检测蔬菜中的硝酸盐含量具有重要的现实意义。本研究对蔬菜中硝酸盐和亚硝酸盐的检测技术进展进行了概述和比较,以期为蔬菜中硝酸盐和亚硝酸盐的检测及快速检测技术的发展提供基础参考。     

分光光度法测定乳粉中亚硝酸盐含量的不确定度评定

目的 研究分光光度法测定乳粉中亚硝酸盐的不确定度评定。方法 以乳粉为例, 参考JJF 1059.1-2012《测量不确定度评定与表示》, 对GB 5009.33-2016《食品安全国家标准 食品中亚硝酸盐与硝酸盐的测定》第二法分光光度法测定亚硝酸盐的不确定度进行评定。结果 乳粉中亚硝酸盐的含量为1.0 mg/kg 时, 测定结果的合成标准不确定度为0.042 mg/kg, 取k=2, 扩展不确定度为0.084 mg/kg, 其结果可表示为(1.0±0.1) mg/kg。结论 测量结果的不确定度主要是标准曲线拟合、标准工作液配制、试样检测重复性和测定用样液体积。前两者引入的不确定度分量贡献较大。