共查询到19条相似文献,搜索用时 156 毫秒
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探讨了改进后的碘量法测定硫化钠时,称样量、沉淀剂用量及酸碱度等因素对分析结果的影响,并通过试验确定了最佳测定条件.试验表明,用改进后的方法与国标法测定试样进行比较,分析结果相符,精密度(n=7)小于或等于1.1%.同一批次样品,分离硫化钠后溶液中亚硫酸钠消耗碘标准滴定溶液的体积V3不变,可作为定值计算,方法简单,达到快速分析的目的. 相似文献
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介绍现代较为常见的有关二甲苯异构体的分离与提纯方法,并对实验室方法和工业化方法进行比较,并利用物理化学的理论研究方法对各种方法进行分析,讨论其适用条件,提出改进设想. 相似文献
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通过用硫氰酸汞分光光度法对空气中氯化氢进行分析,改变不同的测定条件,最终确定最佳分析条件,并对硫氰酸汞-乙醇悬浮液体系做部分改进,即硫氰酸汞-乙醇悬浮液改成硫氰酸汞-乙醇悬浮液沉淀后取上清液放置数周后备用,改进方法的最低检出限为0.25mg/L,回收率为96%以上。 相似文献
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《应用化工》2019,(10):2521-2524
对水中水合肼测定的分光光度法进行了优化性改进。从分析方法研究的角度,对现行水中水合肼测定方法(水质肼的测定对二甲氨基苯甲醛分光光度法)进行了优化和改进性研究,分别从分析方法的检出限、测定下限和测定范围,校准曲线标准点的优化配置,被测样品取样量的科学性等方面出现的问题进行分析,对测试灵敏度的相关因素等方面进行条件实验和比对分析,选择和确定优选的测定条件;并对改进后的方法进行技术评价。结果表明,经过改进后,方法的检出限为0.001 9 mg/L,检测下限为0.007 9 mg/L,有效测定范围为0.007 9~0.14 mg/L。经研究改进后的分析方法,不仅降低了检测下限,提高了检测灵敏度;有效测定范围也得到了合理性拓宽,比原测定方法扩宽了近2倍。精密度和准确度测试符合要求,适合水和废水中肼的测定。 相似文献
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本文阐述了低温甲醇洗工艺中各项工艺条件对硫化物吸收效果的影响 ,并逐项进行了分析和论证 ,提出了改进措施和处理方法 ,在生产实践基础上对净煤气中有机硫的控制提出了改进方法 相似文献
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《应用化工》2022,(10):2521-2524
对水中水合肼测定的分光光度法进行了优化性改进。从分析方法研究的角度,对现行水中水合肼测定方法(水质肼的测定对二甲氨基苯甲醛分光光度法)进行了优化和改进性研究,分别从分析方法的检出限、测定下限和测定范围,校准曲线标准点的优化配置,被测样品取样量的科学性等方面出现的问题进行分析,对测试灵敏度的相关因素等方面进行条件实验和比对分析,选择和确定优选的测定条件;并对改进后的方法进行技术评价。结果表明,经过改进后,方法的检出限为0.001 9 mg/L,检测下限为0.007 9 mg/L,有效测定范围为0.007 9~0.14 mg/L。经研究改进后的分析方法,不仅降低了检测下限,提高了检测灵敏度;有效测定范围也得到了合理性拓宽,比原测定方法扩宽了近2倍。精密度和准确度测试符合要求,适合水和废水中肼的测定。 相似文献
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镧改性材料对水中磷酸盐去除的研究进展 总被引:1,自引:0,他引:1
在各种除磷技术中,吸附法因其成本低、操作简单、设计简单而受到广泛关注;稀土镧由于对磷酸盐具有特异性而被广泛运用于复合吸附剂中,以增强吸附磷酸盐的能力。文中综述了近几年来用于磷酸盐去除的镧改性复合材料吸附剂的研究进展,主要包括镧氧化物/氢氧化物、镧改性铝/铁、镧改性黏土矿物、镧改性碳材料和镧改性其他材料,考虑了镧改性后吸附剂的吸附容量、pH及回收情况等。在进一步的研究中,应考虑镧改性复合材料吸附剂在复杂条件下的稳定性和潜在风险,以及其高效分离和再生的能力。 相似文献
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The polypyrrole (PPY)‐modified electrode made through electropolymerization of pyrrole monomer is found sensitive to different cations depending on the dopants present within microstructure of polymeric domain. When p‐toluenesulfonate (PTS) anion is doped, the modified electrode is sensitive to proton whereas, under similar conditions, in the presence of tetraphenylborate (TPB) anion, the same is sensitive to zinc ion. A comparative study on ion sensing behavior of PPY‐modified electrodes is reported in this communication. The electro‐polymerization of PTS‐doped PPY‐modified electrode, made under both potentiodynamic and potentiostatic conditions, are studied. The modified electrode is characterized by scanning electron microscopy and cyclic voltammetry and compared with those recorded for TPB‐doped PPY‐modified electrode made under similar conditions. The results based on scanning electron microscopy and cyclic voltammetry suggested; (i) dependence of microstructure based on mode of electropolymerization; (ii) dopant‐dependant ion sensitivity of PPY‐modified electrode, (iii) variation in the redox behavior of the PPY‐modified electrode based on dopants and mode of electropolymerization. Typical results on pH sensing together stability of PPY‐based pH sensor are reported and compared with those recorded for polyaniline (PANI)‐based pH sensor. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
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Karolina Dydak Adam Junka Agata Dydak Malwina Broyna Justyna Paleczny Karol Fijalkowski Grzegorz Kubielas Olga Anioek Marzenna Bartoszewicz 《International journal of molecular sciences》2021,22(8)
Local administration of antiseptics is required to prevent and fight against biofilm-based infections of chronic wounds. One of the methods used for delivering antiseptics to infected wounds is the application of dressings chemisorbed with antimicrobials. Dressings made of bacterial cellulose (BC) display several features, making them suitable for such a purpose. This work aimed to compare the activity of commonly used antiseptic molecules: octenidine, polyhexanide, povidone-iodine, chlorhexidine, ethacridine lactate, and hypochlorous solutions and to evaluate their usefulness as active substances of BC dressings against 48 bacterial strains (8 species) and 6 yeast strains (1 species). A silver dressing was applied as a control material of proven antimicrobial activity. The methodology applied included the assessment of minimal inhibitory concentrations (MIC) and minimal biofilm eradication concentration (MBEC), the modified disc-diffusion method, and the modified antibiofilm dressing activity measurement (A.D.A.M.) method. While in 96-well plate-based methods (MIC and MBEC assessment), the highest antimicrobial activity was recorded for chlorhexidine, in the modified disc-diffusion method and in the modified A.D.A.M test, povidone-iodine performed the best. In an in vitro setting simulating chronic wound conditions, BC dressings chemisorbed with polyhexanide, octenidine, or povidone-iodine displayed a similar or even higher antibiofilm activity than the control dressing containing silver molecules. If translated into clinical conditions, the obtained results suggest high applicability of BC dressings chemisorbed with antiseptics to eradicate biofilm from chronic wounds. 相似文献
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采用化学共沉淀法制备磁性Fe3O4纳米粒子,以(3-氯丙基)三甲氧基硅烷为偶联剂将壳聚糖共价键合到磁性Fe3O4纳米粒子的表面,通过红外光谱(FTIR)、X射线衍射(XRD)、扫描电子显微镜(SEM)及热重分析(TGA)对其进行了表征。主要研究了不同影响因素(吸附时间、pH值、牛血清白蛋白浓度)下壳聚糖修饰的磁性纳米粒子对牛血清白蛋白(BSA)的吸附性能。结果得到壳聚糖修饰的磁性Fe3O4纳米粒子粒径为20 nm左右,壳聚糖在磁性Fe3O4纳米粒子表面的接枝率为15.40%。研究表明:在不同条件下,与未修饰的磁性Fe3O4纳米粒子相比,经壳聚糖修饰的Fe3O4纳米粒子对BSA均表现出较强的吸附能力。 相似文献