遗传算法-神经网络-流动注射光度法同时测定镍和铁

在遗传算法的应用研究中,总共做了两方面的工作。其一利用遗传算法对神经网络结构参数进行优化;其二对神经网络的初始权重进行优化。得到优化的遗传神经网络GA-BP-ANN。将此网络应用于解析流动注射-光度分析测得的铁(镍)-(5-Br-PADAP)络合物的重叠光谱,建立了不经分离同时测定铁和镍的新化学计量学方法。     

乳化剂OP增溶5-Br-PADAP光度法测定磷矿中微量锰

<正> 磷矿中锰的测定,常用高锰酸法。该法选择性高,但灵敏度低。近年来,以非离子表面活性剂TritonⅩ—100增溶Mn(Ⅱ)—PAN络合物,光度法测定锰,方法的灵敏度高,ε为5.8×10~4。最近有用2(5-溴-吡啶偶氮)-5-=氨基酚(简称5-Br-PADAP)与锰生成红色络合物,亦为Triton增溶,可在水相中光度测定锰,ε为1.1×10~(5(3))。我们在磷     

矿石中锌的快速测定

锌矿、铅锌矿石中锌的定量方法很多,不过一般均用氯化铵-氢氧化铵-过氧化氢或溴分离铁、锰,以高铁氰化钾碘量法测定锌;亦有用更复杂的亚铁氰化钾法的。极谱法测定高含量锌也并不理想。M.A.波波夫提出的碘氟快速法可以不分离干扰物即进行测定,虽较为快速,但不适用于合铁、锰量高的矿石,又需蒸干逐去硝酸,手续麻烦。本文作者用盐酸-过氧化氢分解矿石,以适量的焦磷酸钠与氟化氢铵为掩蔽剂,消除铁、锰的干扰,用高铁氰化钾碘量法测定锌,铁(50%)、锰(12%)的存在均不干扰测定,又不需蒸干逐去硝酸,方法准确而快速。     

主成分回归荧光光谱法同时分析多组分混合体系

采用主成分回归和荧光光谱结合技术,解析光谱重叠严重的多组分光谱数据,对混合体系中的蒽和芘进行同时测定;采用Mtalab7.0编程进行主成分回归分析,用光谱矩阵建立校正模型,并预测未知样品。实验结果表明,主成分回归荧光光谱法对各组分的平均回收率为99.825%~108.86%,可以不经分离进行多组分定量分析,结果满意。     

用2-(5-溴-吡啶偶氮)-5-二乙氨基苯酚改性硅胶富集、分离痕量铜和镍的研究

用载有2-(5-溴-吡啶偶氮)-5-二乙氨基苯酚(5-Br-PADAP)的改性硅胶(5-Br-PADAP-SG)可以分离、富集水样中的铜和镍。研究结果表明,5-Br-PADAP-SG 对铜、镍的最大吸附量分别是30.1μmol/g、16μmol/g。经5-Br-PADAP-SG 柱富集后,先用0.2mol/l 的硫脲(含0.01mol/l HCl)洗脱铜,再用0.2mol/l 的 HClO_4洗脱镍,以5-Br-PADAP 光度法可测定 ppb 级的铜、镍,富集倍数可达200倍以上,分离效果良好。     

人工神经网络光度法同时测定铜(Ⅱ)、镍(Ⅱ)、钙(Ⅱ)和镁(Ⅱ)

在pH为9.60的硼砂-氢氧化钠缓冲溶液、十六烷基三甲基溴化铵(CTMAB)存在下,铜(Ⅱ)、镍(Ⅱ)、钙(Ⅱ)和镁(Ⅱ)与二甲酚橙(XO)发生灵敏的显色反应,所形成的络合物吸收光谱严重重叠,各组分间相互干扰。采用人工神经网络结合分光光度法,设计不经分离同时测定铜(Ⅱ)、镍(Ⅱ)、钙(Ⅱ)和镁(Ⅱ)含量的方法。结果表明:该方法具有良好的准确性,四种金属离子同时测定结果的相对误差绝对值均≤2.74%。     

高灵敏光度法测定水中微量镉

研究了在pH 8.5的硼砂-硼酸缓冲溶液中,在表面活性剂辛基酚聚氧乙烯醚(曲拉通X-100)存在下,Cd(Ⅱ)与2-[5-溴-2-吡啶偶氮]-5-二乙氨基苯酚(5-Br-PADAP)形成有色络合物的条件.络合物的最大吸收波长为560 nm,其络合比为n[Cd(Ⅱ)]:n(5-Br-PADAP)=1:2,表观摩尔吸光系数为3.23×105L/(mol·cm).镉质量浓度在0～320μg/L符合比尔定律.通过巯基棉柱富集、分离,除去大量的干扰离子.该方法灵敏度高,有色络合物稳定时间长,显色温度范围宽,重现性好,应用于水中微量镉的测定,结果满意.     

高灵敏显色剂5-Br-PADAP

2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚(简称5-Br-PADAP),是分光光度测定铀的试剂,灵敏度高,在适当掩蔽剂存在下选择性也较好。最近国内外的许多研究工作都表明,本试剂对很多过渡金属离子来说都是一个较好的显色剂、萃取剂和指示剂。 5-Br-PADAP的结构式为     

钯-5-Br-PADAP—Triton X-100增溶光度法测定微量钯

5-Br-PADAP是许多金属离子的高灵敏显色剂。有人曾用5-Br-PADAP萃取光度法测定钯,摩尔吸光系数为4.3×10~4l·mol~(-1)·cm~(-1)。但因采用有机溶剂萃取,操作繁琐、费时。为了解决这一问题并进一步提高灵敏度,我们试验了在表面活性剂存在下,水相光度法测定钯的可能性。发现在Triton x-100的存     

偏最小二乘——带荧光检测器的高效液相色谱法测定间-甲酚和对-甲酚异构体及其他酚的研究

酚类化合物因具有较强的内源荧光性,所以目前其主要的分析方法为带荧光检测器的高效液相色谱法(FLD-HPLC法),但是由于间-甲酚和对-甲酚异构体具有相似的理化性质,其荧光光谱严重重叠,常规荧光检测HPLC法难以实现间、对-甲酚的同时测定.在原有液相色谱分析多种酚的基础上,采用了偏最小二乘法(PLS)处理间-甲酚和对-甲酚的荧光光谱数据,实现了对模拟样品中间、对-甲酚的分离.     

Solvent extraction separation of titanium(IV), vanadium(V) and iron(III) from simulated waste chloride liquors of titanium minerals processing industry by the trialkylphosphine oxide Cyanex 923

The solvent extraction of magnesium(II), aluminium(III), titanium(IV), vanadium(V), chromium(III), manganese(II) and iron(III) from hydrochloric acid solutions has been investigated using the trialkylphosphine oxide Cyanex 923 (TRPO) in kerosene as extractant. The results demonstrate that titanium(IV), vanadium(V) and iron(III) are extracted into kerosene as TiOCl₂·2TRPO, VO₂Cl·TRPO and HFeCl₄·2TRPO, respectively. On the other hand magnesium(II), aluminium(III), chromium(III) and manganese(II) are not extracted with TRPO from hydrochloric acid solutions (1.0–4.0 mol dm^?3) under the experimental conditions. IR spectral studies of the extracted complexes were further used to clarify the nature of the extracted complexes. The effect of the diluent on the extraction of titanium(IV), vanadium(V) and iron(III) has been studied and correlated with the dielectric constant. The loading capacity of the TRPO system has been evaluated and the potential for the separation and recovery of titanium(IV), vanadium(V) and iron(III) from simulated waste chloride liquors of the titanium minerals processing industry has been assessed. Copyright © 2004 Society of Chemical Industry     

Study Of The Ozone - Manganese Reaction And The Interactions Of Disulfonate Indigo Carmin/Oxidized Manganese Forms As A Function Of pH

Ozone used in preoxidation for water treatment processes allows the removal of inorganic compounds such as iron and manganese. The reactivity of ozone and manganese has been studied in a wide pH range. However, some difficulties appeared in the determination of the different species because of secondary reactions, the main difficulty being the interaction between indigo (used to determine ozone concentration) and manganese dioxide formed during ozonation.     

Adsorption of Fe+3 and Mn+2 from Ground Water onto Maize Cobs Using Batch Adsorber and Fixed Bed Column

Abstract

The removal of iron and manganese from ground water is an important step for producing safe drinking water. A detailed investigation of the sorption of iron and manganese from ground water onto maize cobs is reported. This work deals with determination of adsorption equilibrium isotherms, kinetic, and fixed bed column studies. Results of Freundlich and Langmiur parameters revealed the favorability of maize cobs for adsorption of iron and manganese ions. Kinetic studies were carried out using from ground water samples (El‐Mina Governorate, Egypt). From the kinetic studies, a model is proposed to determine the external mass transfer (Ks) which can be correlated by the following equation Ks =A (mass)^B. where A and B are constants. During the fixed bed column studies, the effect of process variables such as bed height, flow rate, initial concentration, and percentage breakthrough has been investigated. A simplified design method, namely, the bed depth service time (BDST) model has been applied to the experimental data and the results of this analysis are presented. The mechanism of the metal ion sorption on maize cobs was also investigated. Both the calorific values and differential thermal analysis (DTA) data proved that the loaded maize cobs can be used as solid fuel. Pretences of iron and manganese salts catalyze the thermal decomposition reaction toward more flammable gases, which increase their calorific values. The loaded maize cobs are considered a new potential source for energy conversion.     

DTPA、EDTA氨基安替比林衍生物的合成及其金属配合物的弛豫性能研究

二乙三胺五乙酸(DrrPA)酸酐和乙二胺四乙酸(EDTA)酸酐与4-氨基安替比林(4-AAP)反应，合成了含氨基安替比林的配体DTPA-4-AAP和EDTA-4-AAP，并分别合成了与Gd(Ⅲ)、Fe(Ⅲ)、Mn(Ⅱ)的配合物，配体和配合物用IR、^1HNMR与元素分析做了结构表征。测定了配合物的体外弛豫效率，获得了较好的结果。     

中碳锰铁矿中锰和铁的连续测定研究

文章就中锰矿中锰和铁的测定进行了研究。在pH为5．4的六亚甲基四胺-盐酸缓冲介质中,以Cu＋EDTA—PAN-6S作混合指示剂,用EDTA络合滴定锰;在pH为5．0的HAc-NaAc缓冲介质中,以PAN-6S为指示刺,甩EDTA络合滴定铁;终点变色敏锐,准确度高,锰、铁比例在1：10～10：1范围之间相互无影响。此方法可用于中锰矿中锰和铁的连续测定,结果令人满意。     

高锰酸盐复合药剂预氧化处理微污染水

通过生产性试验考察了高锰酸盐复合药剂预氧化处理微污染水的除污染效能.结果表明,高锰酸盐复合药剂预氧化强化了对浊度、有机物及铁、锰等污染物质的去除,并且与常规工艺相比能较好地控制出厂水三卤甲烷的生成量.     

火焰原子吸收法测定液体肥料中的铜锌铁锰

应用火焰原子吸收法测定液体肥料中的铜、锌、铁、锰,并对测定条件、干扰因素进行了综合考察。该方法简便、快速,适用于多元素液肥生产控制分析和样品系统分析     

共振光散射法测定水中痕量总锰

建立一种环境水样中总锰的共振光散射分析新方法。在pH=6.0的Tris-HC l缓冲溶液中,锰(Ⅶ)氧化二甲基亚砜(DMSO)成为二甲基砜(DMSO2),生成的Mn2+与DMSO2结合形成离子缔合物,使体系的共振光散射急聚增强。在优化的实验条件下,在6.3×10-9~7.5×10-5mol/L浓度范围内,体系的△I值与锰(Ⅶ)浓度之间具有良好的线性关系,线性回归方程为△IRLS=-217.3+114.7 c(r=0.999 1);检出限为1.9×10-9mol/L;样品加标回收率为102.3%~106.5%。该法简便,特异,灵敏度高。用于环境水样中总锰的测定,结果满意。     

光化学还原偶合沉淀反应无线磁弹性传感器法测定铀(Ⅵ)

发现铀(Ⅵ)在紫外光的照射下可以被异丙醇还原成铀(Ⅳ),而铀(Ⅳ)可以使铁(Ⅲ)与铁氰化钾溶液产生沉淀,产生的沉淀可沉积到磁弹性传感器上使其共振频率发生变化。基于这些发现,建立了无线传感法测定铀(Ⅵ)的新方法。在铁(Ⅲ)、铁氰化钾和硫酸浓度分别为0.01、0.01和0.5 mol/L的条件下,测定铀(Ⅵ)的线性范围为0.12～14.1μg/mL,检出限为0.02μg/mL。应用该方法测定了实际样品中的铀(Ⅵ),回收率为96.7%～104.0%。