傅里叶变换红外光声光谱法在聚合物研究中应用——Ⅱ.定量测定组合浆料中变性聚乙烯醇

本文叙述了用傅里叶交换红外光声光谱法测定组合浆料中变性聚乙烯醇和淀粉醋酸酯混合比的快速定量分析方法。变性聚乙烯醇和淀粉醋酸酯的红外光声光谱和红外吸收光谱具有相同图谱。观察了干涉仪动镜扫描速度,扫描次数及试样用量对红外光声光谱信号强度的影响。以变性聚乙烯醇的C=O伸缩振动1570cm~(-1)作为定量分析依据。变性聚乙烯醇含量与1600～1516cm~(-1)范围内的积分强度值成线性关系。用红外光声光谱法测定混合试样中变性聚乙烯醇含量与真实值相吻合。     

双波长系数补偿法同时测定铜铁

研究了以5-Br-PADAP为显色剂,双波长系数补偿法同时测定铜、铁.根据试验结果,选择铜测定波长对为542/570nm,铁测定波长对为560/512nm.对混合物中铜、铁测定,本法比相应的双波长法灵敏度高,铜提高87%,铁提高38%.铜线性范围为0.5～15.0μg/25ml,铁线性范围为0.5～15.0μg/25ml,应用于食品中铜、铁的测定,均得到较满意的结果.     

对乙酰基偶氮胂双波长吸光度差法测定钙

研究了对乙酰基偶氮胂与钙的显色反应.结果表明,在pH10.7的氢氧化钠介质中形成1:2稳定的蓝色格合物;以520nm为参比波长,630nm为测定波长,用双波长吸光度差法测得ε_(520～630)=2.l×10~4.钙量在0～30μg/25ml范围内符合比耳定律.本法用于高纯铁粉、钛酸钙、锆酸钙烧结物及水样中钙量的测定,结果令人满意.     

双波长光度法同时测定水中微量铁和铜

提出了以5 Br PADAP为显色剂,在pH3.0的缓冲溶液中,用双波长光度法同时测定=590.水中微量铁和铜的最佳条件。选择的测定铁和铜的波长对分别为λFe1=503.5nm,λFe2=555.0nm,服从比耳定律的线性范围和检出限分别为0～16μg/25ml和0nm,λCu1=604.0nm,λCu20～24μg/25ml,0.008和0.006μg·ml-1,加标回收率分别为89.2%～105.4%和88.4%～102.0%。通过测定不同的水样,结果满意。     

涂料中甲醛的分光光度测定新方法

在FeCl3存在的盐酸介质中,甲醛与蛋白胨反应生成紫色化合物,最大吸收波长555 nm,甲醛浓度在1~25μg/10 mL范围内,吸光度与浓度成线性关系,线性相关系数r2=0.9997,检出限0.05μg/mL。用本法测定经活性炭脱色的水溶性涂料中的甲醛含量,回收率为96.46%~103.32%,相对标准偏差(n=6)为1.36%~2.09%。     

阻抑氧化藏红T动力学光度法测定痕量铱

基于在稀硫酸介质中,痕量铱对溴酸钾氧化藏红T褪色反应的阻抑作用,建立了一个测定痕量铱的动力学光度法。非催化体系与催化体系在530nm波长处的吸光度差值与铱的浓度在0.08～0.18μg/25ml范围内呈良好的线性关系,检出限为7.03×10-11g·ml-1。对0.15μg/25ml铱(Ⅳ)测定11次的相对标准偏差为0.36%。方法用于冶金产品及岩矿中铱测定的相对标准偏差为1.02%～1.88%,加标回收率为98.6%～102.4%。     

硒钼杂多酸—罗丹明B离子缔合物显色反应的研究与应用

研究了在聚乙烯醇分散剂存在下 ,硒 钼酸铵 罗丹明B(RDB)三元缔合物的显色反应。建立了测定硒碘盐中微量硒的新方法。离子缔合物的最大吸收波长为 5 70nm ,表观摩尔吸光系数ε570 =5 .6× 10 5L·mol- 1·cm- 1。在测定条件下 ,硒含量在 0～ 6μg/ 2 5ml范围内符合比耳定律。对于硒碘盐样品的测定 ,RSD≤ 2 .5 % ,结果满意     

间氯偶氮安替比林光度法测定球化剂中钙

用间氯偶氮安替比林作显色剂,在0.1mol·L~(-1)氢氧化钠介质中,吸光光度法测定球化剂中钙.该显色剂与钙所形成的络合物最大吸收波长为625nm,表观摩尔吸光系数为1.5×10~4,钙量在0～40μg/25ml范围内符合比耳定律.方法适宜测定球化剂1%～5%钙含量.     

双波长吸光光度法同时测定饮用水中钙和镁

研究了以偶氮胂Ⅲ作显色剂 ,用双波长吸光光度法同时测定水中钙和镁的最佳条件。测定钙和镁的最佳波长对分别为 6 5 0～ 5 93nm和 6 15～ 6 6 5 .5nm ,服从比耳定律的线性范围分别为0～ 12 μg/ 2 5ml和 0～ 18μg/ 2 5ml,检出限分别为 0 .0 1和 0 .0 18μg·ml- 1,加标回收率分别在 97 2 %～ 10 4 .5 %和 89.8%～ 92 .8%之间。将此法应用于饮用水中钙和镁的测定 ,结果满意。     

邻苯二酚紫与铝的双峰双波长光度法研究

在pH6.0～6.3的六次甲基四胺 HCl缓冲溶液中,铝 邻苯二酚紫(PCV)络合物在580nm和448nm处有正负两个吸收峰,据此建立了痕量铝的双峰双波长吸光光度法,铝在0～6μg/25ml浓度范围内遵守比耳定律,摩尔吸光系数为9.51×104L·mol-1·cm-1,该法用于灌木饲料中痕量铝的测定,回收率为96.0%～106.0%,结果满意。     

Complexation of polyvinyl acetate with iodine

Polyvinyl acetate and iodine form a characteristic red complex in the presence of potassium iodide. Spectrophotometry of the complex at 510 nm in a methanol-water system at 20 degrees yields linear calibration curves over the range 25-100 mg of polyvinyl acetate per 1. of final solution. The limit of detection is 0.1 mg of polyvinyl acetate in 0.5 ml of initial sample. Replacement of acetate groups by inert groups reduces the sensitivity of the method, and other details of the system are discussed.     

Simultaneous Determination of Lidocaine (Lignocaine) and Thiopental in Plasma Using High Pressure-Liquid Chromatography

Abstract

A sensitive and precise high-pressure liquid chromatographic method for the simultaneous quantitation of lidocaine (lignocaine) and thiopental in 0.5 ml samples of plasma is described. Extraction was conducted at pH 7.0 using ethyl acetate, and bupivicaine was employed as an internal standard. The drugs were eluted from a reversed-phase column using a mobile phase consisting of aceton-itrile/0.2 M phosphate buffer pH 4.0 (1:9) at a flow rate of 1.0 ml/min. The drugs were detected and quantified by their UV absorption at 205 nm. The sensitivity limits of detection for lidocaine and thiopental were 1 ug/ml and 5 ug/ml, respectively. Atropine, caffeine and meperidine were found to have interfering retention times.     

Simultaneous determination of cyproterone acetate and ethinylestradiol in tablets by derivative spectrophotometry

Derivative spectrophotometry offers a useful approach for the analysis of drugs in multi-component mixtures. In this study a third-derivative spectrophotometric method was used for simultaneous determination of cyproterone acetate and ethinylestradiol using the zero-crossing technique. The measurements were carried out at wavelengths of 316 and 226 nm for cyproterone acetate and ethinylestradiol respectively. The method was found to be linear (r2>0.999) in the range of 0.5-6 mg/100 ml for cyproterone acetate in the presence of 35 microg/100 ml ethinylestsradiol at 316 nm. The same linear correlation (r2>0.999) was obtained in the range of 10-80 microg/100 ml of ethinylestradiol in the presence of 2 mg/100 ml of cyproterone acetate at 226 nm. The limit of determination was 0.5 mg/100 ml and 10 microg/100 ml for cyproterone acetate and ethinylestradiol respectively. The method was successfully applied for simultaneous determination of cyproterone acetate and ethinylestradiol in pharmaceutical preparations without any interferences from excipients.     

Simultaneous Determination of CGS 10787B and Its Major Metabolite (CGS 12094) in Plasma by High Performance Liquid Chromatography

Abstract

A method for the simultaneous determination of CGS 10787B and its major, metabolite (CGS 12094) in plasma is described. The two compounds, and the internal standard (dichlorinated analog), are extracted from acidified plasma with ethyl acetate, taken to dryness, and reconstituted in chromatographic mobile phase. The analytes are determined automatically by high performance liquid chromatography in the reversed-phase mode as paired ions, using [N(Bu)₄]⁺ as the counterion. The separation of the compounds is achieved on a 3u C-8 column, with detection at 254 nm.

Recovery and reproducibility assessments indicate good accuracy and precision over the range of 1.0 to 250 ug/ml for CGS 10787B and 1.0 to 100 ug/ml for CGS 12094.

The method has a limit of detection of 0.2 ug/ml for both compounds, and has been shown to be adequate for studying the disposition kinetics of CGS 10787B.     

Sago/PVA blend membranes for the recovery of ethyl acetate from water

Sago starch is a relatively new polymeric material for development of a hydrophilic membrane for dehydration of alcohol/water. In this study sago based membranes were developed through casting technique for the dehydration of ethyl acetate at azeotropic conditions via pervaporation. Sago was blended with polyvinyl alcohol (PVA) to produce blended sago–PVA membranes with improved physical and chemical properties. The membranes were cross-linked using three different approaches; firstly, using glutaraldehyde, secondly using thermal treatment (80 °C) and thirdly by using both glutaraldehyde and thermal treatment. The effects of various cross-linking methods on the intrinsic properties of hydrophilic polymer membrane were investigated. The membranes were characterized using Fourier transform infrared (FTIR), differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). The effect of operating conditions such as feed temperature and concentration on the separation factor and flux was discussed. Sago starch polymer shows very high performance and very good stability after polymer blending and cross-linking, which is promising for use in industrial applications.     

特大孔交联苯乙烯-二乙烯苯共聚物的制备和孔结构研究Ⅰ

本文以聚乙酸乙烯酯配合其它溶剂(如乙酸乙酯、正辛醇、二氧六环等)作致孔剂,制成了一系列孔径在数万埃,孔容为1ml/g(干树脂)左右的苯乙烯-二乙烯苯系特大孔交联共聚物,并进行了部分功能基反应,制成了强碱阴离子交换树脂,还讨论了一些实验结果。     

Glue compositions based on polyvinyl acetate and its derivatives

The possibilities of improving the properties of binding materials based on polyvinyl acetate and its derivatives are considered. It is shown that an enhancement of the quality of polyvinyl acetate glues for tobacco industry can be achieved through changes within certain limits of formulation and technological parameters of the vinyl acetate polymerization process. It is found that using modified polyvinyl alcohol as a polymer additive for grouting mortars favors the improvement of their quality. In the oil industry, this additive enhances the adhesion of grouting mortar with a contact surface of a well-producing zone and reduces water trapping. An investigation was conducted of the production process of polyvinyl butyral, which carries different amounts of acetate groups; as a result, the conditions of synthesis for achieving the optimal content of these groups are defined. It is shown that a high content of acetate groups gives one the ability to significantly improve the physicomechanical characteristics of the films based on polyvinyl butyral.     

叶绿素α/聚乙烯醇光电化学电池的研究

太阳能的开发利用是目前备受重视的研究课题,国内外对半导体太阳能电池已有很多研究。用叶绿素作为色素光敏剂来开发利用太阳能,国外在七十年代以来已进行了不少工作^[1-7]。     

电感耦合等离子体原子发射光谱(ICP-AES)法测定铸造用硅砂中的Fe2O3、Al2O3、CaO、MgO、TiO2、K2O、Na2O

建立了电感耦合等离子体原子发射光谱(ICP-AES)法测定铸造用硅砂中Fe_2O_3、Al_2O_3、CaO、MgO、TiO_2、K_2O、Na_2O的方法。研究了溶样方法的选择优化,采用硝酸、氢氟酸溶样,冒高氯酸处理,通过元素分析线的选择,基体和共存元素影响的消除,在最佳的仪器分析条件下得出了方法的线性范围、相关系数及检出限。用硅砂3个梯度含量的标准物质的分析结果评价方法的准确度和精密度。方法的检出限Fe为0.012μg/mL、Al为0.032μg/mL、Ca为0.27μg/mL、Mg为0.003 2μg/mL、Ti为0.002 1μg/mL、K为0.16μg/mL,Na为0.000 44μg/mL。5次数据的相对标准偏差说明方法稳定性较好。方法适用于铸造用硅砂中Fe_2O_3、Al_2O_3、CaO、MgO、TiO_2、K_2O、Na_2O含量的测定。