盐湖法制碳酸锂产品中硫酸根杂质的测定

目前还没有报道对盐湖法生产碳酸锂中硫酸根杂质测定较理想的方法,有色金属行业标准"电池级碳酸锂YS/T582—2006"推荐使用分光光度计硫酸钡比浊法的测定方法,但是这一方法应用到盐湖法碳酸锂中硫酸根杂质的测定时精度不够高。在大量测定盐湖法碳酸锂中硫酸根杂质的工作经验基础上,通过比较多种测定方法,提出了将标准加入法应用到比浊法中的测量方法,即"标准加入比浊法",来测定盐湖法碳酸锂产品中硫酸根的含量。该方法测定结果的相对标准偏差为0.051,回收率为98.8%～100.5%,说明本方法具有良好的精密度和准确度。方法简便、快速、准确度高,适合于硫酸根质量分数为0.005%～0.08%的碳酸锂样品中硫酸根杂质的测定。     

溶剂萃取法从褐藻浸提液中分离提取褐藻糖胶

用溶剂萃取法分离提取了实际海藻浸提液中的褐藻糖胶. 考察了接触时间、溶剂加入量及萃取剂浓度等对萃取的影响，并与从多糖配制液中的萃取情况进行比较. 考察了无机盐水溶液反萃褐藻糖胶的性能及在溶剂中加入TOA(三正辛胺)对萃取和反萃的影响，结果表明，季铵盐从实际鼠尾藻浸提液中萃取褐藻糖胶受溶剂加入量的影响很大，溶剂加入量越大，萃取率越低；而萃取时间对萃取的影响不大. 海带浸提液的萃取优于鼠尾藻浸提液，而超声破碎法有利于萃取. TOA的加入既有利于褐藻糖胶的萃取也有利于无机盐水溶液反萃褐藻糖胶. 采用溶剂萃取法制备的固体褐藻糖胶的纯度优于乙醇分步沉淀法制备的固体褐藻糖胶的纯度.     

褐藻糖胶的萃取和反萃

研究了无机盐种类和浓度对N263萃取褐藻糖胶的影响. 结果表明,无机盐浓度是影响褐藻糖胶萃取的最主要因素, 褐藻糖胶的萃取率随盐浓度的增加而迅速降低,在无机盐存在下,增加萃取剂浓度并不能增加对褐藻糖胶的萃取. 用盐水溶液反萃不同条件下萃取的褐藻糖胶,结果表明,反萃率随盐浓度的增加而增加,在相同的氯离子浓度下,钠盐的反萃效率优于钙盐,随有机相中褐藻糖胶浓度的增加, 盐的反萃效率降低. 比较了不同溶剂作为稀释剂对用盐溶液反萃褐藻糖胶的影响,表明CCl4作为稀释剂时盐的反萃效率最低.     

卤水中硫酸根含量测定方法的探索

详细阐述了测定卤水中硫酸根含量的硫酸钡质量法、铬酸钡容量法、EDTA容量法和ICP间接测定法。比较了各个方法的特点。根据测定要求及条件选择合适的测定方法。     

燃烧法测定镀铬液中的硫酸根

一测定方法的提出及理论依据镀铬液中硫酸根的含量对于镀层质量和电流效率有着显著的影响。因此,快速测定镀铬液中的硫酸根,较好地控制镀铬液中硫酸根的含量具有重要的意义。硫酸根的测定通常用硫酸钡重量法,硫酸钡沉淀—EDTA滴定法,离心沉降法。前种方法速度太慢,后二种方法是对前法的改进。但分析精密度和准确度都较差。近年来,对硫酸根的测定作过不少的研究,提出了氢碘酸—次磷酸—盐酸混合试剂还原硫化铅光度法,苯甲酸银沉淀分离大量铬EDTA滴定法,磷换活性炭蒸馏碘量法,苯甲酸银分离铬—阳离子交酸钡电极法,小型Al_2O_3柱—铅电极法,四苯硼     

氯化钙中硫酸根离子的快速测定

通过试验研究论证利用721型分光光度计,在酸性介质中,钡离子与硫酸根离子生成难溶硫酸钡,使溶液浑浊,采用乙醇作稳定剂,利用分光光度计进行比色,并对一组氯化钙产品中硫酸根质量分数进行快速测定,测定结果与重量法测定结果进行分析和比较,证明该方法能够为客户提供准确、可靠的分析结果,是一种准确测定氯化钙中硫酸根的快速分析方法。     

混合离子交换树脂纯化褐藻糖胶的工艺研究

研究了混合离子交换树脂(按001×7强酸性苯乙烯系阳离子交换树脂和201×7强碱性阴离子交换树脂质量比1:1混合)对褐藻糖胶粗品的脱盐纯化工艺,同时考察了三氯乙酸法对褐藻糖胶溶液的脱蛋白效果。通过单因素实验,对影响混合离子交换树脂脱盐效果的料液比及脱盐时间进行了分析;通过研究溶液中蛋白质及总糖含量的变化规律,得出三氯乙酸法脱蛋白实验方法中三氯乙酸试剂的最佳添加量。结果表明:当料液体积与混合离子交换树脂质量的比例为1:3,脱盐时间为60分钟时脱盐效果最佳,脱盐率可达65.12%。三氯乙酸法脱蛋白实验方法中三氯乙酸试剂的最佳添加量为13%(V/V),脱蛋白率为85.17%。研究所确定的纯化工艺可以作为纯化分离褐藻糖胶的较佳工艺加以推广。     

超声波协同酶法提取海带多糖工艺优化及海带饮料配制

以山东地区海带为原料,采用超声波协同复合酶法提取海带多糖及海带饮料。确定海带多糖最优提取条件:纤维素酶质量分数为0.3%、果胶酶质量分数为0.7%、木瓜蛋白酶质量分数为1.5%、温度为55℃、pH为5.5、固液比为1∶150、反应时间为4 h,迅速将反应体系升温至90℃并保温1 h;灭酶后,55℃水浴下超声反应30 min。该方法提取的海带多糖得率为19.4%,褐藻糖胶得率为6.96%。海带饮料最佳配方:白砂糖质量分数为5%,柠檬酸质量分数为0.12%,蜂蜜质量分数为3%,草莓香精质量分数为1.5%。     

硫酸生产尾气中硫酸雾含量测定方法改进

借鉴盐酸中硫酸根测定方法,用硫酸钡比浊法测定硫酸生产尾气中的硫酸雾含量,测定结果与环保在线监测数据吻合,相对标准偏差0.2%,加标回收率为96.0%～102.0%,准确度高,精密性好,操作简单、快速,成本低廉,可广泛应用。     

褐藻糖胶吸湿、保湿性能的研究

以甘油和山梨醇为参照物,分别在两种相对湿度下考察了褐藻糖胶粗品和较纯品的吸湿、保湿率以及随时间的变化情况,并且探讨了保湿剂的选择原则.结果表明,褐藻糖胶具有一定程度的吸湿性和较持久的保湿性,尤其在较干燥环境下,保湿性优于甘油和山梨醇.因此,其作为保湿剂有着一定的应用前景.     

展进新法方定测素骨软酸硫化酸硫多中钠素肝染污

介绍了污染肝素钠中多硫酸化硫酸软骨素的结构、性质及来源,并对其测定方法进行了综述.     

芒硝中十水硫酸钠含量的测定方法

探讨了十水硫酸钠的两种测定方法——滴定法和重量法,经对比说明了重量法的准确性和重现性更好,更适合黑龙江昊华化工有限公司芒硝中十水硫酸钠含量的测定.     

High performance liquid chromatographic determination of sodium sulfate in anionic surfactants

Sodium sulfate is separated from anionic surfactants on a separation column packed with strong anion exchange resin, and is detected by a post column derivatization method based on a chemical reaction between sulfate and ferric ion. A calibration curve shows a linear relationship in the range of 10\s-300 mg/100 mL for sodium sulfate. The lower limit of determination is 2 mg/100 mL. Anionic surfactants such as sodium alkylbenzene sulfonate and sodium alkyl sulfate do not interfere with the determination. A personal computer was connected to the chromatographic system for data processing and control of an automatic sampler. This personal computer controlled liquid chromatographic system provides good recovery, reproducibility, agreement with conventional methods and full automatic determination.     

Analytical methods for alpha sulfo methyl tallowate

Recent economic trends have made sulfo methyl tallowates viable alternatives to oil-based synthetic detergents in certain applications. Currently available analytical methods to monitor and control product quality are rather limited and sketchy, however, meaning that a substantial amount of methods development has been required. This includes methodology for resolving the three types of sulfonates present, and for the determination of sodium methyl sulfate. This paper describes new methods developed for making these determinations. They include a new two-phase dye transfer titration and a potentiometric ion-selective electrode titration for the resolution of sodium alpha sulfo tallowate and sodium alpha sulfo tallow acid. In addition, a new method involving saponification and two-phase dye transfer or potentiometric ion-selective electrode titrations for the determination of sodium methyl sulfate is described.     

Determination of total and water-insoluble-combined lactic acid in lactic acid modified fatty glycerides

Analytical methods for the determination of total and water insoluble combined lactic acid in lactic acid modified fatty glycerides are described. The acids are liberated from their esters by saponification. Lactic acid is determined by simple acid-base titration after removal of fatty acids via liquid-liquid extraction. Water soluble constituents are extracted from a dichloro-methane solution of the esters with 5% aqueous sodium sulfate prior to determination of water insoluble lactic acid. Methods are rapid, simple, and suitable for use in a plant control laboratory. Extension of the procedure provides for the simultaneous determination of fatty acid and glycerine on a single sample.     

Flow injection analysis of water. Part 1: Automatic preconcentration determination of sulphate,ammonia and iron(II)/iron(III)

This paper describes a simple flow-injection (FI) manifold for the determination of a variety of species in industrial water. The chemical systems involved in the determination of ammonia (formation of Indophenol Blue), sulfate (precipitation with Ba(II)), and iron (complexation with 1,10-phenanthroline with the help of a prior redox reaction for speciation) were selected so that a common manifold could be used for the sequential determination of batches of each analyte. A microcolumn of a suitable ion exchange material was used for on-line preconcentration of each analyte prior to injection; linear ranges for the determination of the analytes at the ng/ml levels were obtained with good reproducibility. The manifold and methods are ready for full automation.     

Determination of sodium sulfate in anionic surfactants by nonaqueous titration

A convenient and easy method was developed for nonaqueous titrimetric determination of sodium sulfate in the presence of sulfonate and sulfate type anionic surfactants. Sodium sulfate and the anionic surfactants were converted to sulfuric acid and the corresponding organo-sulfonic or organo-sulfuric acids by the addition of an excess of perchloric acid. The resulting acid mixture was then titrated in methanol with cyclohexylamine. The sulfate content was calculated from the difference of the two end points of the differentiating titration curve. For the determination of sodium sulfate in typical anionic surfactants, the relative standard deviation varied from 0.7 to 2.0% at the 0.3-10% sodium sulfate levels. The method provides a rapid and precise determination of inorganic sulfates in sulfonated or sulfated materials.     

Gesamtkonzept zur Glucosinolatbestimmung — Möglichkeiten zur Erstellung von Bilanzen in Rapssamen und -schroten

A New Concept for the Determination of Total Glucosinolate Content — Possibilities to Draw up Balances in Rapeseed and Rapeseed Meal The indirect analysis of the original total glucosinolate content of rapeseed and rapeseed meal via the determination of released sulfate anion is an interesting alternative to the other methods. While the total sulfate content always represents the total glucosinolate content at the time of harvest, the amount of decomposed glucosinolates in the seeds or meals is represented by the amount of free sulfate. In this way a balance can be made between rapeseed harvest or rapeseed entering the oil mill and rapeseed meal leaving the oil mill. Oil milling processes always lead to a partial degradation of glucosinolates and the resulting meal will contain a variable portion of the original intact glucosinolates. Glucosinolates are hydrolysed during drying, analysing or processing either enzymatically by the action of myrosinase or thermally by the action of heat. In both cases one molecule sulfate is produced from one molecule glucosinolate. With the aid of the sulfate method it is therefore possible to draw up balances especially in rapeseed meal.     

钡镁法快速测定栲胶脱硫液中硫酸钠的含量

采用GB/T 10535—1997仲裁法分析栲胶脱硫液中Na2SO4含量需3 h。采用钡镁法以过量已知浓度钡镁混合液与Na2SO4作用生成硫酸钡沉淀,过量钡镁溶液用EDTA标准溶液回滴,只需0.5 h,可快速测定硫酸钠含量;该法准确度、精密度也可满足生产要求。