硼砂发制海参中硼砂含量的测定研究

比较海参不同发制方法(清水发和硼砂发)对海参形态和重量的影响,通过测定两种方法发制海参后硼砂的含量,了解食用硼砂发制海参的相关风险。基于GB/T 21918-2008,采用电感耦合等离子体发射光谱仪测定清水发制海参和硼砂发制海参中硼砂的含量。通过研究发现,硼砂发制的海参比清水发制的海参在形状和重量上均有明显增大,且用质量浓度为5%的硼砂去发制海参,经过换算,可测得其硼砂含量值高达1795~2132 mg/kg。最后从实验结果可以得出:食用硼砂发制海参存在较高的风险。     

广东地区豆类天然硼砂含量的分析

文章对广东地区的豆类中硼砂本底进行了调查,结果表明:豆类均含有一定量的硼砂,不同产地的黄豆其硼含量存在差异,黄豆的硼含量范围在110.5~205.5 mg/kg之间,其中广州和河源地区黄豆中的硼含量低于韶关地区。其他种类的样品中,黑豆的硼含量较高达到219.0mg/kg。     

紫外分光光度法测定水晶泥中硼砂的含量

建立了一种用紫外分光光度法测定玩具水晶泥中硼砂含量的方法,该方法利用去离子水在37℃条件下萃取水晶泥中的硼砂,用乙基己二醇-三氯甲烷溶液对萃取到的硼砂进行富集,再用姜黄素-冰乙酸对其进行显色,通过比色可以测定样品中硼砂的含量。该方法定量限可低至15 mg/kg,重复性为6.01%,可用于定量分析水晶泥中硼砂的含量。实际操作中,尽量避免玻璃器皿中硼的溶出对测试结果的影响。     

近红外光谱法快速检测腐竹中硼砂的含量

选取市售腐竹作为研究对象,采集样品的近红外光谱,用国标分光光度法测定样品中硼砂的含量作为标准值,结合偏最小二乘法,建立了腐竹中硼砂含量的近红外光谱快速检测模型。结果表明,采用二阶导数谱,在7 150.75～5 924.25 cm^-1光谱区间,经多元散射校正、五点平滑处理建立的模型为较优模型。该模型的校正集线性相关系数(R_c)值为0.994 1,校正集均方根偏差(RMSEC)值为0.050 8,验证集线性相关系数(R_p)值为0.980 6,验证集均方根偏差(RMSEP)值为0.114,主因子数(factors)为10,相对分析误差(RPD)为5.1。模型有较好的稳定性,外部验证结果准确,可以用于腐竹中硼砂含量的快速检测。     

食品中硼砂快速定性方法

采用超声方法快速萃取样品中的硼砂,萃取液与姜黄试剂及氨水产生颜色反应从而快速定性测定硼砂。该方法适用于现场检测,也可制作成快速检测试剂箱。     

腐竹中硼砂检测方法研究与本底讨论

按照GB/T 21918-2008《食品中硼酸的测定》标准中第一法(乙基己二醇-三氯甲烷萃取姜黄比色法)和第二法(电感耦合等离子体质谱法)对市场流通领域抽查的一批腐竹中的硼砂进行检测,并分析比较检测结果。由于硼是植物生长的必需微量元素,大豆等农作物均含有硼的本底,给硼砂的非法食品添加判定带来困难,分析讨论食品中硼砂的本底及限量标准。     

由硼砂矿制备硼砂的工艺研究

采用水浸-冷结晶工艺由天然硼砂矿制取硼砂产品,研究了浸出温度、液固比、浸出时间、结晶温度和结晶时间等因素对浸出和结晶的影响。最优工艺条件：浸出温度为60 ℃,液固体积质量比为2 mL/g,浸出时间为30 min;结晶温度为0～10 ℃,结晶时间为6 h。在最优条件下,硼浸出率大于98%,硼砂结晶率接近94%,硼回收率约92%。制得的硼砂产品杂质含量低,纯度高,产品质量达到GB/T 537-2009《工业十水合四硼酸二钠》一等品指标要求。     

硼砂生产研究进展

介绍了硼砂的用途、物化性质、毒性、生产过程,综述了其近十年来的生产研究进展情况。     

硼泥耐火材料的研究

采用Ｘ射线衍射分析（ＸＲＤ）、扫描电子显微镜分析（ＳＥＭ）及能谱分析（ＥＤＳ）研究了以硼泥为主要原料制备的镁橄榄石质试样的组成和结构，并对试样的力学性能及高温使用性能进行了测试。结果表明，利用工业废料硼泥制备耐火材料是可行的．     

甘露醇和山梨醇在硼砂水溶液中的旋光性研究

在阴极还原葡萄糖研制甘露醇和山梨醇的过程中对甘露醇和山梨醇在硼砂水溶液中的旋光性进行了研究。这两种醇在硼砂水溶液中旋光发生变化的原因是这两种醇能与硼形成配合离子 ,从而增强了其稳定性 ,提高了其灵敏度。找到了旋光度法测定甘露醇和山梨醇混合物的最佳条件 :w(总醇 ) =1 0 % ;w(硼砂 ) =1 2 8% ;静置时间为 1h。以旋光度对甘露醇的浓度做图得到一条直线。理论值和实测值的最大误差为 0 5%。     

从硼泥制取氢氧化镁阻燃剂

本文讨论了从硼泥制备氢氧化镁阻燃剂工艺的适宜条件和影响因素，制得的氢氧化镁纯度〉９４％。比表面积〈２０ｍ＾２／ｇ，平均粒径１μｍ～２μｍ应用试验表明其具有优良的阻燃和消烟性能。     

Determination of the Glucosinolate Content in Commercial Rapeseed Loads with a Pocket Reflectometer

A method is proposed which allows the determination of the glucosinolate content in commercial loads of rapeseed within 10 minutes. The procedure is based on the following steps: Homogenization of 10 g seeds, extraction of the glucosinolates with boiling water, enzymatic hydrolysis of the glucosinolates, removal of interfering substances with activated charcoal paper, detection of the liberated glucose using a glucose test paper, measurement of the colour intensity of the test paper with a pocket reflectometer and calculation of the glucosinolate content on basis of the measured values.     

The Investigation of the Influence of Impeller Blade Inclination on Borax Nucleation and Crystal Growth Kinetics

An influence of impeller blade angle on the crystallization kinetics of borax has been investigated in detail. Its importance was studied in a batch crystallizer equipped with a four-blade turbine, whose angle was varied from 30° to 90°. Heterogeneous nucleation mechanism was dominant at all examined conditions, but the rate of nucleation significantly differed. Kinetic parameters of crystal growth were determined as well. Numerical values of order of crystal growth remain almost unchanged regardless of the blade angle. Different values of crystal growth rate constants are the result of the fluid dynamics in the crystallizer, caused by the different impeller blade inclinations. In all examined systems, crystal growth is integration limited. The transition from axial to radial flow, due to different blade angles, reflects on the crystal size distribution, agglomeration ratio, and crystallization yield.     

赴日考察观感

赴日本参观和考察了井上，信越等13家公司，概述了这些公司的生产和发展状况。     

Toxin Content of Commercial Castor Cultivars

The castor plant Ricinus communis L. is the source of castor oil which has numerous uses and is a key chemical feedstock for an array of products from polymers to cosmetics. Although castor was once widely grown throughout the world, the presence of the toxic protein ricin has deterred the re‐introduction of this useful crop. In order to develop a low‐ricin or no‐ricin castor crop, a robust, accurate method for screening castor seed for ricin content is essential. In this study, we validated a sandwich enzyme‐linked immunosorbent assay for the detection of ricin and the homologous Ricinus communis agglutinin (RCA) in castor beans and screened a collection of castor lines including commercial varieties using this assay. Although the average content derived by extracting several seeds provided a fair representation of the ricin content for a given selection, there was enough seed‐to‐seed variation to justify determining the ricin/RCA content of individual seeds. Ricin levels observed ranged from 1.16 to 6.25 % by weight.