人工神经网络催化动力学光度法同时测定铁和锑

Fe(Ⅱ)和Sb(Ⅲ）对Cr(Ⅵ）-I^-都具有诱导效应,可以利用I2-淀粉的反应分别进行动力学分析。实验观察到,两者共存时对Cr（Ⅵ）-I^-反应的诱导具有协同效应。根据这一现象,在590nm波长下测定不同时间(温度)时协同诱导体系的吸光度,利用人工神经网络处理非线性体系的优势进行数据处理,建立了人工神经网络催化动力学光度法同时测定铁和锑的新方法。该法用于合成样品和土壤样品中铁和锑的同时测定,获得了满意的结果。     

停流流动注射-诱导动力学光度法同时测定微量铁和锑

依据诱导反应的基本原理, 提出了一种同时测定多元素的方法; 研究了Fe(II)、Sb(III)诱导的Cr(VI)-I^-氧化还原反应体系, 并据此建立了停流-诱导动力学光度法同时测定微量铁和锑的工作条件。线性范围分别为0~1.2μg.mL^-1Fe(II)和0~2.0μg.mL^-1Sb(III); 检测限为0.012μg/mL^-1Fe(II)和0.014μg.mL^-1Sb(III)。除Ti(III)、V(IV)及As(III)外, 其余共存离子不影响测定。用本法测定了锌标准物及模拟样品中的铁和锑含量, 结果满意。     

动力学体系中双组份的协同效应研究及其分析应用

用停流ＦＩＡ－分光光度法研究了铬（Ⅵ）－碘化钾动力学反应体系中铁(Ⅱ)和钒(Ⅳ)的协同诱导效应，以协同系数（Ｄ）表示二者相互作用程度的大小，在此基础上提出了一种新的动力学双组份同时测定的方法，本法可扩大前述方法的线性范围，并降低检测限，测定了模拟水样品中铁和钒的含量，结果满意。     

停流FIA─协同系数补偿动力学方法双组份的同时测定

用停流光度法研究了Ｈｇ（Ⅱ）和Ａｇ（Ⅰ）对以硫脲为活化剂的Ｆｅ（ＣＮ）－α，α’－联吡啶配体交换反应的协同催化效应，提出了协同系数的概念。在协同系数补偿动力学体系中由于双组份的协同催化效应而引起的对吸光度加合性的偏离，建立了一种新的双组份同时测定方法，此法使双组份同时测定的线性范围显著扩大，且降低了检测限。测定了环境样品中汞和银含量，获得满意结果。     

不同样品前处理技术对同时测定土壤中铊和锑的影响

为了比较不同前处理方法对土壤中重金属铊和锑的同时提取能力,采用3种加热方法和8种消解体系的不同组合对4种标准土壤样品进行处理。实验探究了不同前处理方法并结合电感耦合等离子体质谱(ICP-MS)进行检测,通过精密度和准确度的分析,优化了同时检测铊和锑两种重金属元素的最合适的样品前处理方法。研究结果表明,电热板加热HNO_3-HF体系和微波消解HNO_3-HF-HCl-HClO_4体系,结合ICP-MS能够更加准确的同时测定重金属铊和锑。将最适合的两种前处理方法分别用于4个实际样品的处理,结果表明上述两种不同的消解体系对土壤中铊和锑的提取能力基本一致。本研究方法可以同时准确的测定土壤样品中的铊和锑。     

电铸液中微量铁钛同时测定的研究

利用5-溴水杨基荧光酮、CTMAB与Fe(Ⅲ)、Ti(Ⅳ)形成的三元配合物显色体系,采用联机检测技术,结合流动注射方法,对双组分金属离子进行了速差动力学同时测定的研究,并且测定了电铸液中Fe(Ⅲ)的含量.结果表明,方法不仅扣除了Ti(Ⅳ)的干扰,而且测定了Ti(Ⅳ)的含量.方法的回收率在96%～106%之间.样品处理手续简便,电铸液中其它组分基本不干扰测定.     

自动电位滴定法测定锑矿石中锑

建立了自动电位滴定法测定锑矿石样品中锑含量,确定了相关滴定参数和等当点识别标准。该方法用H2SO4-K2SO4分解样品,用硫酸肼将样品中的Sb(Ⅴ)还原为Sb(Ⅲ),以硫酸铈为滴定剂,滴定反应在HCl介质中进行。用该方法对3种锑矿石标准样品GBW07280,GBW07279和GBW07176进行连续5次测定,相对标准偏差范围为0.40%~0.84%;并且用于5种铁含量较高的锑矿石样品中锑含量的测定,回收率在96.1%~102%。本法适用于1.80%以上锑含量的测定。与手动滴定法相比,该方法不受样品溶液颜色限制,锑含量为33 mg/L时,铁含量超过1.40 g/L也不干扰测定,解决了手动滴定使用甲基橙指示剂判定终点难的问题,有推广价值。     

流动注射-化学发光法直接测定土壤中的锑(Ⅲ)

利用锑(Ⅲ)对鲁米诺-双氧水化学发光体系的催化作用,建立了一种直接测定锑(Ⅲ)的新方法.锑(Ⅲ)浓度的对数在5×10-8～5×10-5g/L范围内与发光强度呈线性关系,相关系数r=0.9991,检测限为2×10-9g/L.对5×10-8 g/L的标准溶液连续测定11次,测定结果的相对标准偏差为2.37%.将该法应用于土壤样品中锑(Ⅲ)的检测,加标回收率为90%～105%.     

挥发排锑-电感耦合等离子体质谱法测定铅锑精矿中铊

采用盐硝混酸+氢氟酸溶解样品,氢溴酸挥发除锑的方法,避免高含量锑在溶液中不稳定及对铊测定的干扰,采用电感耦合等离子体质谱法测定了铅锑精矿中铊的含量。铅锑精矿经过前处理后,样品溶液中锑的残留量均小于10μg/m L。选择铱作内标,将方法应用于实际样品中铊的测定,相对标准偏差小于5%,回收率为97.2%~107%,选择6家试验室协同验证,经统计检验测试结果间无明显差异。方法适用于铅锑精矿中铊的测定。     

氢化物发生-原子吸收光谱法测定锑(Ⅲ)和锑(Ⅴ)

提出在酸性条件下以氟化钠为掩蔽剂测定锑(Ⅲ),在碱性介质中加入氟化钠消除价态的影响测定锑总量,两者相减求出锑(Ⅴ),实现对锑(Ⅲ)和锑(Ⅴ)的分别测定.研究了在酸性介质中测定锑(Ⅲ)及碱性介质中测定锑总量的条件及共存离子的干扰和消除.工作曲线的线性范围为：0～20 μg·L-1锑(Ⅲ);0～80 μg·L-1锑(Ⅴ),相关系数大于0.999,方法的检出限为0.31 μg·L-1锑(Ⅲ),0.69 μg·L-1锑(Ⅴ).对水样和土壤样品进行了测定,相对标准偏差(RSD)小于5%.     

The mutual catalytic effect in kinetic reactions and its application to simultaneous determination of binary components

The mutual catalytic effect between iron(II) and antimony(III) on the chromium(VI)-iodide kinetic reactions has been studied by stopped-flow FIA. The concept of mutual catalytic coefficient is defined. The deviations from additive principles of absorbance within certain concentration ranges in previous procedures can be compensated effectively, by introducing the mutual catalytic coefficient into the simultaneous determination of a binary mixture with stopped-flow-FIA method. The linear concentration ranges have been enlarged, 0–3.5 g/ml Fe(II) and 0–3.7 g/ml Sb(III) compared with 0–1.2 g/ml Fe(II) and 0–2.0 g/ml Sb(III) without use of the coefficient. Iron and antimony contents in wastewater, a simulated sample and a zinc standard were determined, the recoveries and relative standard deviations being, respectively, 99.8–101.3% and 2.7–3.6% for iron and 95.4–100.3% and 2.3–5.3% for antimony compared with 95.2–98% and 3.0–4% for iron and 96–104% and 4.5–4.8% for antimony, assuming additivity.     

Flame‐retardancy of a Cellulosic Fabric by the Application of Synergistic Effect between Ammonium Bromide and Antimony(III) Oxide

The synergistic effect between ammonium bromide and antimony(III) oxide as a nondurable finish on the flammability of 100% woven plain cotton fabric (with a density of 144 g/m2, the number of yarns 21 per 10 mm), has been investigated in this study. The laundered totally-dried, weighed specimens were impregnated with suitable concentration individual aqueous ammonium bromide and/or antimony(III) oxide suspension solutions and some sets were impregnated with appropriate admixed solutions of the both chemicals. A vertical flame spread test was then carried-out to characterize the flammability of the samples. An acceptable synergistic effect was then experienced by using an admixed bath containing 0.1 molar ammonium bromide and 0.05 unit formal antimony trioxide solutions for impartation of flame-retardancy to a cotton fabric. The optimum mass of the mixture required to impart flame-retardancy was about 3.64 g of anhydrous additives per 100 g of fabric. The results obtained are in favor of Wall Effect Theory. Moreover synergistic effect indicating dehydration of the treated substrate by using this combination via thermogravimetry could be deduced.     

堆积模型在萃取中的应用I: 水相介质协同效应

根据推积模型提出一种新的协萃体系,即:(简单阴离子)1+(简单阴离子)2+萃取剂,并以实验证实了水相混合介质的协同效应.研究了UO2/OAc,C1/TBP-二甲苯体系的协萃效应,测定了萃合物的组成以及各种影响分配比的因素.     

Direct determination of bismuth and antimony in sea water by anodic stripping voltammetry

A method based on anodic stripping voltammetry at the mercury-coated graphite electrode has been developed for the direct determination of bismuth and antimony at their natural levels in sea water. Bismuth plated at -0.4 V from sea water made 1 M in hydrochloric acid gives a stripping peak proportional to concentration at -0.2 V without interference from antimony or other metals normally present. Antimony may be plated from sea water made 4 M in hydrochloric acid and gives a stripping peak at -0.2 V proportional to the sum of bismuth and antimony. By use of the standard addition technique, satisfactory results were obtained for sea water samples with concentration ranges of 0.02–0.09 μg kg^?1 for bismuth and 0.2–0.5 μg kg^?1 for antimony.     

取代苯σ·Ⅱ效应分离与FMO能量的相关性 △E~X~.~σ~P^H^O研究

研究了芳环上取代基诱导效应能和共轭效应能的分离,Ph(X)~n的(X)n基属性从能量角度提出量化解释及应用,发现各类芳环取代基都不同程度存在两种σ~c、σ~1效应,且存有群轨道作用。     

Anodic stripping voltammetry of antimony at unmodified carbon electrodes

Antimony is an element of significant environmental concern, yet has been neglected relative to other heavy metals in electroanalysis. As such very little research has been reported on the electroanalytical determination of antimony at unmodified carbon electrodes. In this paper we report the electrochemical determination of Sb(III) in HCl solutions using unmodified carbon substrates, with focus on non-classical carbon materials namely edge plane pyrolytic graphite (EPPG), boron doped diamond (BDD) and screen-printed electrodes (SPE). Using differential pulse anodic stripping voltammetry, EPPG was found to give a considerably greater response towards antimony than other unmodified carbon electrodes, allowing highly linear ranges in nanomolar concentrations and a detection limit of 3.9?nM in 0.25?M HCl. Furthermore, the sensitivity of the response from EPPG was 100 times greater than for glassy carbon (GC). Unmodified GC gave a comparable response to previous results using the bare substrate, and BDD gave an improved, yet still very high limit of detection of 320?nM compared to previous analysis using an iridium oxide modified BDD electrode. SPEs gave a very poor response to antimony, even at high concentrations, observing no linearity from standard additions, as well as a major interference from the ink intrinsic to the working electrode carbon material. Owing to its superior performance relative to other carbon electrodes, the EPPG electrode was subjected to further analytical testing with antimony. The response of the electrode for a 40?nM concentration of Sb(III) was reproducible with a mean peak current of 1.07?µA and variation of 8.4% (n?=?8). The effect of metals copper, bismuth and arsenic were investigated at the electrode, as they are common interferences for stripping analysis of antimony.     

Comprehensive study of the effect of composition on the flame-retardant activity of antimony oxide and halogenated hydrocarbons in thermoplastic polymers

Flame retardance has been studied in the systems (a) antimony (III) oxide and decabromobiphenyl in acrylonitrile-butadiene-styrene terpolymer (ABS) and (b) antimony (III) oxide and chlorinated paraffin in high-density polyethylene (HDPE). Values of limiting oxygen index for over 70 compositions in each system have been measured and fitted by fourth-order polynomials. The triangular plots of these polynomials show complexities of the systems which cannot be revealed by traditional methods. Optimum atomic ratios for this synergistic system were found to be higher than the commonly accepted value of 3: Br/Sb = 9 and Cl/Sb = 6–7. ABS was found to be more amenable to flame retardance than HDPE; possible reasons are discussed.     

A comparison of different analytical techniques (energy dispersive X-ray fluorescent spectrometry, bomb calorimetry combined with ion chromatography and inductively coupled plasma-optical emission spectrometry) for the determination of the bromine and antimony content of samples

In recent years, there has been intensive research into the use of pyrolysis to process toxic plastics from waste electrical and electronic equipment (WEEE). During pyrolysis, the fate of the bromine and antimony content of the plastics is critical therefore, new and improved analytical techniques for analysing these elements in the pyrolysis products are being sought. In this work, the effectiveness of energy dispersive x-ray fluorescent spectrometry (EDXRFS) for the determination of bromine and antimony content of pyrolysis oils from waste electrical and electronic equipment have been tested. Samples were obtained by the pyrolysis of brominated high-impact polystyrene (Br-HIPS) and brominated acrylonitrile-butadiene-styrene (Br-ABS) at temperatures from 360 to 440 °C. The concentration range of both the bromine and antimony in the samples was very broad (0.05-17.94 wt% and 0.03-8.54 wt% respectively). The results from EDXRFS to those of more traditional and time consuming methods; bomb calorimetry combined with ion chromatography (EPA method 5050) for bromine and acid digestion combined with inductively coupled plasma-optical absorption spectrometry for antimony were compared.Based on our measurements, different statistical parameters were calculated for each analytical technique, which demonstrated that EDXRFS had been successfully applied to the determination of bromine and antimony concentration in the pyrolysis oils of Br-HIPS and Br-ABS. Errors resulting from matrix effects did occur, in particular correlations were found between the nitrogen content of the samples and the difference in bromine and antimony measured by EDXRFS and other methods (ion-chromatography and ICP-OES). However, these differences were found to be statistically insignificant, so we could conclude that EDXRFS is a suitable technique for analysing the bromine and antimony content of pyrolysis oils.     

Determination of total antimony(III,V) by square-wave anodic stripping voltammetry with in situ plated bismuth-film electrode

A sensitive and reliable method is described for the determination of total Sb(III,?V) at traces levels by Osteryoung square-wave anodic stripping voltammery (OSWASV). This method is based on the co-deposition of Sb(III,?V) with Bi(III) onto an edge-plane pyrolytic graphite substrate at an accumulation step. OSWASV studies indicated that the co-deposited antimony was oxidised with anodic scans to give an enhanced anodic peak at about 450?mV vs. Ag/AgCl (sat. KCl). The anodic stripping peak current was directly proportional to the total concentration of antimony in the ranges of 0.01–0.10?µg?L^?1, 0.10–1.0?µg?L^?1 and 1.0–18.0?µg?L^?1 with correlation coefficient higher than 0.995 when 2.0?mol?L^?1 hydrochloric acid was used. The detection limits calculated as S/N?=?3 was 5.0?ng?L^?1 in 2.0?mol?L^?1 hydrochloric acid at 180?s deposition time. The relative standard deviation was 5% (n?=?6) at 0.10?µg?L^?1 level of antimony. The analytical results demonstrate that the proposed method is applicable to analyses of real water samples.