对加碘盐不同取样方法与准确性关系的

在对加碘食用盐进行碘含量检测时,各检验员对如何取"均匀"样品的认识和操作手法存在一定的差距.这一差距将直接导致同一样品不同的操作手法造成检验结果有很大偏差,严重时直接导致合格产品被误判为不合格,不合格产品反而被判合格.本文就是对不同的操作手法进行系列实验,研究其产生误差的原因,消除由于操作手法不同而带来的检测误差.     

对加碘盐不同取样方法与准确性关系的试验研究

在对加碘食用盐进行碘含量检测时，各检验员对如何取“均匀”样品的认识和操作手法存在一定的差距。这一差距将直接导致同一样品不同的操作手法造成检验结果有很大偏差，严重时直接导致合格产品被误判为不合格，不合格产品反而被判合格。本文就是对不同的操作手法进行系列实验，研究其产生误差的原因，消除由于操作手法不同而带来的检测误差。     

影响加碘食盐碘含量检测结果准确性的因素分析及改进措施

<正>加碘食盐碘含量检测是保证食品安全的一个重要方面,而碘含量检测的准确性则关系到加碘食盐是否符合相关要求,实际的检测中碘含量检测准确性容易受到影响,造成了对加碘食盐合格性判断的失误。本文主要探讨的是影响加碘食盐碘含量检测结果准确性的因素及改进措施,首先分析了加碘食盐碘含量测定取样方法,同时通过试验的方法对加碘食盐碘含量实施检测,其次对影响结果准确性的因素进行分析,并重点就直接滴定法中影响碘含量的因素进行分析,最后     

消泡剂对啤酒双乙酰检测结果的影响

本公司在考核检验员检测啤酒双乙酰含量准确度时,发现同一样品经不同检验员检测,结果有时会偏差很大,对检测过程每个细节进行排查,其它条件（蒸馏时间、定容温度、暗处反应时间和温度等）均控制一致,唯一不同的是加消泡剂的量（国标GB4928．2001啤酒检测标准中规定,蒸馏双乙酰时允许加1～2滴消泡剂）,有些检验员加一滴消泡剂,有的加2滴消泡剂,使同一样品的检测结果不一样。根据这一现象,我们进一步进行多组对比试验,试验结果如下：     

食盐碘含量的检测方法及多品种盐辅料对碘含量测定的影响

碘是人体必需的一种微量元素,从全民补碘到科学补碘,食盐加碘一直是全社会关注的焦点。不论人体摄入的碘过量或不足都是有害健康的,因此碘含量是食盐产品最重要的监测指标,而检测方法的适用性是保证结果准确的基础。文章综述了食盐碘含量的检测方法,并对几种多品种盐的辅料对碘含量测定的影响进行了分析与探讨,以期为食盐中碘含量的准确监测提供参考。     

关于提高食盐中加碘均匀性问题的探讨

本文针对食盐实际生产过程中加碘指标出现波动的异常情况,分析产生的原因,找出影响加碘均匀性的主要因素是食盐粒度的不均匀,阐述了粒度在食盐生产过程中对碘含量均匀性控制的重要性,提出实施控制食盐粒度的具体措施,通过改进生产工艺,加强生产过程控制,有效提升了食盐中碘指标的均匀性。     

广州市:79批次定配眼镜产品不符合标准要求

<正>日前,广州市质量技术监督局在其官网公布了2015年广州市定配眼镜产品质量监督抽查结果,此次共抽查了500家眼镜店的500批次产品,经检验有79家眼镜店的79批次产品不符合标准要求。不合格项目涉及柱镜轴位方向、光学中心水平距离、光学中心单侧水平偏差、光学中心垂直互差等。其中,有29批次产品光学中心单侧水平偏差不合格。造成该项目不合格的主要原因是企业质检人员未对该项目进行严格检验,有的企业甚至根本未对该项目进行质检。     

2004～2013年湖南省加碘食盐碘含量检测结果与分析

检测湖南省加碘食盐碘含量,为碘缺乏病的消除及防治提供科学决策依据。根据GB/T 8618—2001《制盐工业主要产品取样方法》取样和《食盐卫生标准》检测,2004~2013年每年每个季度在全省14个地级市各大型超市抽取不同品种的加碘食用盐样品。结果表明:2004~2013年共抽取和检测加碘食用盐样品1 680份,加碘食盐碘含量平均值为27.31~33.98 mg/kg,加碘食盐中碘含量中位数为27.58~33.70 mg/kg,符合GB 5461—2000和GB 26878—2011中关于碘含量的规定。加碘食盐中碘含量合格率为95.55%~100%,且呈稳步提高趋势。     

食用盐碘含量检测结果准确性影响因素分析

食用盐作为日常生活必需的膳食调味品,所含的碘与多种碘缺乏病息息相关.如果消费者日常摄入的盐中碘含量低于合格的盐,会直接因缺碘引发疾病,且影响人体健康.所以,食盐中碘含量的检测有着非常重要的作用.本文从企业食用盐中的碘含量检验中可能存在的一些问题,对企业食用盐的工业生产与食用加工过程涌现的安全监管风险及其产生规律机制问题...     

蚕丝被检测中的质量问题及对策

作者结合实际工作中对蚕丝被的检测结果,归纳出蚕丝被检测中发现的质量问题主要有:产品标识不规范,纤维含量与实际不符,填充物品质不达标,填充物含油率超标,填充物的质量偏差率不达标,填充物压缩回弹性不合格等。对出现以上问题的原因进行了分析,提出了相应的解决措施。     

新标准食用盐碘添加技术改造初探

主要针对食用盐碘含量新标准规定,简要介绍制盐生产企业为提高食用盐碘含量添加精度,满足食用盐碘含量新标准要求,而对生产设备、工艺及添加方式进行的技术攻关与改造,以及新、老工艺设备添加结果对比分析,以期能给同行在今后改造过程中借鉴参考。     

Standardized evaluation of iodine nutrition in West Africa: the African phase of the thyromobil program

Extensive programs of iodine supplementation by iodated salt have been implemented in Africa during the last decade. The present work evaluated their effectiveness in Benin, Burkina Faso, Mali, and Togo. A van equipped with a sonographic device visited 39 sites in the four countries. The prevalence of goiter was evaluated on the basis of the determination of thyroid volume by ultrasonography in 4,011 randomly selected 6- to 12-year-old schoolchildren of both sexes in the 39 sites. The concentration of urinary iodine was measured in 1,545 of these children. The iodine content of table salt collected at home by the children was measured by test kits in 3,202 salt samples, 415 of which were also analyzed by titration. Based on the results obtained by the kits, 83.7% to 97.9% of the salt samples contained iodine. However, the test kits had a low sensitivity and specificity in comparison with titration. The median urinary iodine was within an acceptable range (100-300 14 g/L) in the four countries, but almost one-third of the values were still below normal. The prevalence of goiter was normal (< 5%) in Benin and Togo, and it was 22.4% and 13.4%, respectively, in Burkina Faso and Mali. These results indicate marked improvement of the status of iodine nutrition in comparison with the situation reported only a few years ago in the same countries, but quality control of the iodine content of salt and monitoring of the iodine status of the populations need to be improved.     

Adding an oxidant increases the stability of iodine in iodized salt

It has been shown that moisture plays a critical role in the stability of iodine and that reducing agents in iodized salt reduce the stability of iodine. We question whether this is valid in all cases, and have found that the reducing agent may play a more important role than moisture in decreasing the stability of iodine. We reviewed current methods to enhance iodine retention in iodized salt, and propose methods to produce stable iodized salt and to analyze its stability. Our experiments showed that when reducing impurities are removed, iodine remains stable in iodized salt, even when the salt is "wet." We suggest that the stability of iodine in iodized salt can be improved by oxidizing iodized salt with sodium hypochloride, and that the iodine content of iodized salt, after heating at 120 degrees C for one hour, can be used to reflect the quality of iodized salt. We have demonstrated that reducing agents play a critical role in the stability of iodine in iodized salt. We have shown a method of purifying salt by removing reducing materials, which can be used to produce iodized salt with sufficient stability at lower cost. We also propose an analytical method to determine the stability of iodine in iodized salt. These methods could be further developed to achieve better accuracy, precision, and reliability and be applied to a greater variety of iodized salts.     

富硒低钠盐中碘含量的测定

目的探讨富硒低钠加碘盐中碘含量的测定方法。方法通过不同的实验条件,优化国标GB/T13025.7-2012《制盐工业通用试验方法碘的测定》中氧化还原滴定法中的试剂用量,检测出富硒低钠加碘盐中的碘含量。结果改变碘化钾溶液量、淀粉溶液量、磷酸-草酸溶液量均无法测定富硒低钠盐中的碘含量;只有当次氯酸钠溶液用量≥5mL时,加入碘化钾溶液,才可以使富硒低钠加碘盐溶液显色,然后通过实验确定次氯酸钠的最佳用量,再滴定测定碘含量。结论富硒低钠加碘盐中含有还原性物质,测定其碘含量需加大次氯酸钠溶液的用量。     

Iodine nutrition: iodine content of iodized salt in the United States

Adequacy of iodine nutrition in the United States has lately been of concern. A major source of dietary iodine for the U.S. population is iodized salt. The U.S. Food and Drug Administration (USFDA) recommends 60-100 mg Kl/kg salt, equivalent to 46-76 mg l/kg salt. All U.S. iodized salt contains 45 mg l/kg according to labels. We collected samples of table salt from freshly opened containers from U.S. volunteers. A sample was sent to us when the can was first purchased. Subsets of volunteers sent further samples when the salt container became half-empty through normal use and a further final sample when the container was nearly finished. We also looked at iodine distribution homogeneity within individual containers, loss of iodine from salt upon exposure to humidity and sunlight, and upon short-term heating (dry and in solution) as may be encountered in cooking. Measurements were made in 0.01% w/v salt solutions by induction coupled plasma-mass spectrometry with 72Ge as an internal standard. The median and mean (+/-sd) I content in freshly opened top-of-the-can salt samples was 44.1 and 47.5 +/- 18.5 mg/kg (n=88, range 12.7-129 mg l/kg) and geometric mean and standard deviation of 44.70 and 1.41. Forty-seven of 88 samples fell below the USFDA recommended I content while 6 exceeded it. The homogeneity in a single can of salt varied greatly: in 5 samples taken from the same container from different depths, the iodine content varied by as little as 1.2x (8.3% coefficient of variance (CV)) to as much as 3.3x (49.3% CV) from one container/brand to another. Iodine is significantly lost upon high humidity storage but light or dry heat has little effect. There is much recent literature on iodine sufficiency and uptake inhibitors; there is also much misinformation and disinformation. We review the relevant literature and discuss our results with reference to the United States.     

海藻中碘的形态及其食用安全性研究进展

碘是人体甲状腺激素合成的必需元素,也是人体必需的微量元素之一。依据世界卫生组织提出的食盐加碘补碘策略, 1994年我国颁布了《食盐加碘消除碘缺乏危害管理条例》。但长期过量摄入无机碘,不仅会引起甲状腺功能失调,增加患甲状腺癌的几率,还会导致其他组织器官病变。海藻是天然的食用碘资源,有机碘含量最高达80%。通过海藻碘、有机碘和无机碘的毒性研究发现,长期大量摄入海藻碘和有机碘对甲状腺的危害要小很多。本文分析了我国补碘现状及国内外碘的限量,对比海藻碘、有机碘和无机碘的毒性差异,阐述当前海藻碘的毒性研究进展,为进一步开展海藻碘的食用安全性评估和制定碘的限量提供参考。     

Fast and reliable salt iodine measurement: evaluation of the WYD Iodine Checker in comparison with iodometric titration

Iodine deficiency persists as the leading cause of preventable brain damage and reduced intellectual capacity in the world. The most effective method for the elimination of iodine deficiency is the consumption of adequately iodized salt. Ensuring that a population receives adequately iodized salt demands careful monitoring of the salt iodine content. We evaluated the WYD Iodine Checker, a hand-held instrument that quantitatively measures the salt iodine content on the basis of a colorimetric method, and compared its performance with iodometric titration. Performance testing results indicated that the WYD Iodine Checker is a highly precise, accurate, and sensitive tool for measuring salt iodine content. It is a user-friendly instrument that is based on a simple methodology and a straightforward salt sample preparation and testing procedure. We recommend further testing to examine the field performance of the WYD Iodine Checker when measuring iodate salt samples.     

测定食盐碘含量及其影响因素研究

用碘离子选择性电极测定食盐中碘含量并对影响因素进行探讨。在Na2SO3作还原剂,双盐桥甘汞电极作参比电极的条件下,引入表面活性剂,使碘离子的浓度在2.0×10-7mol/L~1.0×10-2mol/L范围内的对数与响应电位值呈良好的线性关系。试验结果显示:碘盐中的碘含量为27.22 mg/kg,均达到国家标准,同时讨论温度、时间等对碘含量的影响。碘的回收率在94.99%～106.3%之间,相对标准偏差RSD≤3.23%。     

Stability of iodine in salt fortified with iodine and iron

BACKGROUND: Determining the stability of iodine in fortified salt can be difficult under certain conditions. Current methods are sometimes unreliable in the presence of iron. OBJECTIVE: To test the new method to more accurately estimate iodine content in double-fortified salt (DFS) fortified with iodine and iron by using orthophosphoric acid instead of sulfuric acid in the titration procedure. METHODS: A double-blind, placebo-controlled study was carried out on DFS and iodized salt produced by the dry-mixing method. DFS and iodized salt were packed and sealed in color-coded, 0.5-kg, low-density polyethylene pouches, and 25 of these pouches were further packed and sealed in color-coded, double-lined, high-density polyethylene bags and transported by road in closed, light-protected containers to the International Council for the Control of Iodine Deficiency Disorders (ICCIDD), Delhi; the National Institute of Nutrition (NIN), Hyderabad; and the Orissa Unit of the National Nutrition Monitoring Bureau (NNMB), Bhubaneswar. The iodine content of DFS and iodized salt stored under normal room conditions in these places was measured by the modified method every month on the same prescribed dates during the first 6 months and also after 15 months. The iodine content of DFS and iodized salt stored under simulated household conditions was also measured in the first 3 months. RESULTS: After the color code was broken at the end of the study, it was found that the DFS and iodized salt stored at Bhubaneswar, Delhi, and Hyderabad retained more or less the same initial iodine content (30-40 ppm) during the first 6 months, and the stability was not affected after 15 months. The proportion of salt samples having more than 30 ppm iodine was 100% in DFS and iodized salt throughout the study period. Daily opening and closing of salt pouches under simulated household conditions did not result in any iodine loss. CONCLUSIONS: The DFS and iodized salt prepared by the dry-mixing method and stored at normal room conditions had excellent iodine stability for more than 1 year.     

Stability of iodine in iodized fresh and aged salt exposed to simulated market conditions

BACKGROUND: The salt iodization law of the Philippines required that iodized salt sold at retail not be exposed to direct sunlight, high temperature and relative humidity, and contamination with moisture and dust from the environment. However, because the majority of local consumers buy salt displayed in open heaps, it was suggested that iodized salt should be sold in the same manner for greater accessibility and availability. Objective. We aimed to provide evidence on the stability of iodine in local aged and fresh salt iodized at 100 ppm iodine and exposed to various market and storage conditions. METHODS: Samples of salt in open heaps and repacked salt were exposed for 4 weeks, and salt packed in woven polypropylene bags was stored for 6 months. The iodine content of the salt was determined by the iodometric titration method, and the moisture content was determined by the oven-drying method. RESULTS: For all types of exposed salt, iodine levels were above 60 ppm after the end of the study (4 weeks). Within each salt type, losses were greater for open-heap salt than for repacked salt. The greatest drop in moisture content occurred in the first week for most types of salt and exposure combinations. Moisture content was linearly correlated with iodine content. Iodine levels in stored salt remained above 60 ppm even after 6 months. CONCLUSIONS: Iodized salt is able to retain iodine above the recommended levels despite exposure to an open environment and use of ordinary packaging materials while being sold at retail and kept in storage.