异烟酸-吡唑啉酮光度法快速测定水体中氰化物

在磷酸缓冲介质中,水体中氰化物与氯胺T反应生成氯化氰,再与显色剂(异烟酸 吡唑啉酮)作用生成红色中间产物后进行比色测定。研究了氯胺T浓度、反应温度、显色时间的影响,找出最佳测定条件。方法的线性范围为0.006～1.0mg·L-1,检出限为0.006mg·L-1。该方法准确,快速,操作简便,能较好地应用于水质在线监测。     

滴定法快速测定白酒中的氰化物

蒸馏酒与配制酒统称为白酒。白酒中的氰化物是在粮食糖化发酵过程中产生的一种物质。白酒中氰化物的测定在ＧＢ/Ｔ5 0 0 9.4 8- 1996中采用异烟酸 吡唑酮比色法 ,该法操作复杂 ,对酸碱度和温度要求严格。由于氯胺Ｔ试剂极易分解变质 ,往往使试验失败 ,市售新出厂的氯胺Ｔ一时又买不到 ,使试验无法进行。本法采用试银灵为指示剂 ,用硝酸银标准溶液滴定白酒中氰化物 ,本法简便、快速、准确 ,能满足白酒卫生标准要求 ,结果满意。1　试验部分1.1　原理在碱性溶液中 (ｐＨ >11)以试银灵作指示剂 ,用硝酸银标准溶液滴定 ,形成银氰络合离子 ,到达…     

原子吸收光谱法测定白酒中锰

锰是构成人体骨骼所必需的微量元素,也是制取甲状腺素非常重要的物质。它能使食物充分消化吸收,能缓解神经过敏和烦燥不安,能解除疲劳,增强记忆力,能预防骨质疏松症。成人每天摄入2～5mg即可满足生理需要。超过这个数量就会中毒,所以要监测包括酒在内食品中锰的含量。     

Evaluation of the Chemiluminometric Method for Determination of Polyphenols in Wine

The Pholasin chemiluminometric method for determination of polyphenols in wine was evaluated by comparison with liquid chromatography with mass-spectrometric detection. The results were also compared with the conventional Singleton-Rossi spectrophotometric method for determination of total polyphenols.

A total of 141 wine samples were examined using all three methods and the results indicated a good agreement between the chemiluminometric and the Singleton-Rossi methods; however, the chromatographic data correlated reasonably well with the chemiluminometric data only for gallic acid, but less well or not at all with other determined phenolic antioxidants: trans-resveratrol, (+)-catechin, (?)-epicatechin, quercetin, vanillic-, caffeic-, caftaric-, p-coumaric-, 3,4-dihydroxybenzoic-, ellagic-, sinapic-, ferullic-, and ellagic acid.     

毛细管气相色谱法测定白酒中甜蜜素

甜蜜素是一种广泛使用的甜味剂,甜度是蔗糖的50倍[1],其化学名称为环己基氨基磺酸钠.在GB/T 10781.1-2006<浓香型白酒>中规定不得添加非白酒发酵产生的呈香呈味物质,本方法利用毛细管气相色谱法测定白酒中甜蜜素.该方法前处理无需离心,操作过程简便,分析时间短,回收率试验结果表明,该方法准确可靠.     

蒸发浓缩-火焰原子吸收光谱法测定白酒中铅

铅是白酒必须控制的卫生质量指标之一[1,2],过量的铅会损害神经、造血和生殖系统,尤其对儿童的危害更大,可影响儿童生长发育和智力发展,铅污染的控制已成为世界关注热点和发展趋势.火焰原子吸收光谱法测定白酒中铅含量一般要经过一定前处理如消化和萃取、共沉淀分离富集、黄原酯棉分离富集,操作繁琐,使用试剂多[3-6].基体中酒精含量高,如直接用火焰原子吸收光谱法进行测定,干扰很大.本文提出通过用水浴蒸发样品以驱赶酒精,再用火焰原子吸收光谱法进行测定.该法操作简单、快速、环保,准确度高,能满足白酒卫生指标的日常监测工作和企业质量控制要求.     

白酒中甲醇的测定与检定简况

白酒在我国农村具有很大市场。一些不法商人以谋取暴利为目的 ,常以含有甲醇的工业酒精勾兑为饮用白酒出售 ,造成饮用者严重的伤亡后果 ,危害极大。如何对白酒中微量的甲醇进行测定与检定 ,是分析工作者既紧迫又艰难的任务。我国对饮用白酒中甲醇的限量为小于 0 0 4 9ｍｇ·Ｌ-1。甲醇为毒物 ,对血管有麻痹作用及可导致神经变性 ,严重损害视神经。饮用 8～ 2 0ｍｌ甲醇可失明 ,服 30ｍｌ甲醇即可导致死亡。1　白酒中甲醇的氧化从乙醇中定量测定或定性检定甲醇 ,均需将甲醇氧化为甲醛后进行检测。氧化甲醇的方法有铜丝氧化法 ,文献 [1,2 ]报…     

Simultaneous Determination of Organotin Compounds in White Wine by Gas Chromatography-Mass Spectrometry

A simple, reliable, and effective analytical method was developed for the simultaneous determination of five organotin compounds (OTCs) including monobutyltin trichloride dibutyltin dichloride tributyltin chloride tetrabutyltin and triphenyltin chloride in white wines. The OTCs were derivatized with sodium tetraethylborate (NaBEt₄), and their derivatives were extracted by liquid-liquid extraction (LLE) into n-hexane. The experimental variables, such as type and volume of extraction solvents, amount of derivatization reagent NaBEt₄ and extraction time were optimized. The determination of ethylated derivatives of OTCs in the final extracts was carried out by gas chromatography-mass spectrometry (GC-MS). Under optimized conditions, good linearity was observed when analytical concentrations were in the range of 0.01–4.0 µg · mL^?1, the linearity correlation coefficients were between 0.9982 and 0.9987, with the LODs in the range of 0.2–3.0 µg · L^?1, and the LOQs varied from 0.6 to 10.0 µg · L^?1. The obtained recoveries were in the range of 78.0–120.0%, with the relative standard deviations equal to or lower than 8.1%. This method was applied to the determination of OTCs in white wines with satisfactory results.     

大豆含油率分析测定方法的改进

大豆是含高油脂、高蛋白的重要农产品。通常对大豆的含油率测定是采用乙醚作为溶剂，通过索氏(Soxhlet)油脂抽提器测定，一次只能测定一个样品，而且需要近一天时间，操作麻烦。本法在传统方法的基础上，进行研究和改进，试验出大豆含油率的测定新方法。     

流动注射光度法测定水中总磷方法的改进

对全自动流动注射分析仪的分析流路进行了改进,将先消解后进样的模式改为先进样后消解的模式,提出了一种改进的流动注射光度法测定水中总磷含量的方法。总磷的质量浓度在0.01～2.0mg.L-1范围内与吸光度呈线性关系,检出限(3S/N)为1.4μg.L-1。方法用于水样中总磷的测定,经t-检验测定值与国标法测定值无显著差异。水样的加标回收率在93.0%～105.0%之间。