氰氟草酯及其代谢物在稻田水、土壤和稻株中的残留分析方法

研究并建立了氰氟草酯及其 4种代谢物在稻田水、土壤及稻株中的残留分析方法。在同一色谱分析条件下 ,同时检测 5种化合物 ,样品前处理过程简单 ,方法准确可靠 ,灵敏度和准确度达到了农药残留检测的要求。氰氟草酯及 4种代谢物在上述样品中的最低检知浓度在 0 .0 2～ 0 .0 0 4mg kg之间 ,方法的添加回收率(0 .0 1～ 5mg kg)在 80 .2 %～ 1 0 1 .2 %之间     

金矿含氰废水处理技术

介绍了金矿含氰废水的处理方法及新的处理技术,并对其原理及优缺点进行了分析。     

溴氰虫酰胺及其代谢物在辣椒和土壤中的残留降解研究

建立了超高效液相色谱-串联质谱法(UPLC-MS/MS)测定辣椒和土壤中溴氰虫酰胺及其代谢物(J9Z38)残留量的方法,研究了溴氰虫酰胺和J9Z38在辣椒和土壤上的降解特性。样品经乙腈提取后用C18固相萃取柱净化,采用梯度洗脱程序、BEH C18色谱分离柱、应用UPLC-MS/MS正离子扫描测定溴氰虫酰胺和J9Z38。进行了添加浓度为0.01、0.10和1.00 mg/kg的回收实验,溴氰虫酰胺和J9Z38在辣椒和土壤中的日内平均回收率为88.6%~105.7%,日内相对标准偏差为3.8%~15.1%;日间平均回收率为91.4%~105.3%,日间相对标准偏差为4.9%~12.3%。溴氰虫酰胺和J9Z38在2.0~128.0μg/L浓度范围内相关系数r>0.9992,定量限分别为0.1和0.2μg/kg。应用本方法检测了田间实验样品,结果表明,溴氰虫酰胺在辣椒和土壤中降解半衰期分别为9.2~11.2 d和9.2~20.8 d,J9Z38在辣椒中残留量低于定量限,在土壤中降解半衰期为9.4 d;随着降水量增加,溴氰虫酰胺降解速度加快。     

电解法处理含氰废水

电镀车间含氰废水,来源于镀件在氰化镀槽电镀后表面附着带出的氰镀液,再经流动水漂洗后就产生大量含氰废水。氰为剧毒物质,若不经处理,直接排入水体,将严重污染环境,破坏水体资源,危害人民健康。     

敌百虫在棉花和土壤中的残留研究

建立了敌百虫在棉花和土壤中残留量的高效液相色谱-电喷雾质谱(HPLC-ESI/MS)测定方法.该方法最小检出量为1.5×10-11 g,最小检出浓度在植株和土壤中均为0.05 mg/kg,加样回收率为植株71%～76%、土壤96%～103%、棉籽74%～79%,相对标准偏差分别为3.2%～16%、5.2%～12%、4.8%～6.5%.本法快速、灵敏、准确,可以用于敌百虫的残留分析.降解动态和最终残留研究结果表明,敌百虫在植株和土壤中的半衰期(T50)分别为0.4～0.6 d和0.5～1.2 d;以推荐剂量施药2～3次,或以2倍推荐剂量施药2～3次,采收间隔21 d,棉籽和土壤中敌百虫残留量均低于0.05 mg/kg.     

速收除草剂在大豆及土壤中的残留动态

 采用 Zorbax SIL色谱柱、以二氯甲烷 -甲醇为流动相的高效液相色谱法 ,测定了速收除草剂在大豆田土壤和大豆上的残留动态 ,建立了样品前处理方法和分析方法。速收在土壤、青豆和大豆籽粒的添加回收率分别为84.82 %～ 85 .63 % ,88.79%～ 94.0 0 %和 93 .70 %～ 94.48%。速收在土壤中的半衰期 (t1 / 2 )为 1 0 .0～ 1 0 .5 d,降解速度较慢 ,但在收获期的土壤、青豆 (用药后 80～ 85 d)和大豆籽粒中均未检出 ,说明其残留污染性很小 ,可以在大豆田安全使用。     

苯醚甲环唑在香蕉和土壤中的残留分析方法研究

建立了苯醚甲环唑在香蕉和土壤中的残留分析方法。样品经乙腈或丙酮、乙酸乙酯提取,中性氧化铝柱净化,GC-ECD检测。方法在0.004~0.4μg/mL范围内有良好的线性关系,香蕉和土壤中苯醚甲环唑最低检测质量分数为0.004 mg/kg。样本中添加量为0.004~1.0 mg/kg时(n=5),平均回收率为81.4%~106.3%,相对标准偏差为1.5%~11%;方法的准确度和精密度均满足农药残留分析的要求。     

灭多威在小白菜中的残留分析方法

建立了灭多威在小白菜上乙腈提取、硅胶层析净化,高效液相色谱(紫外检测器)检测的残留分析方法,该分离效果好,灵敏度高,线性关系良好.以3.0,1.0,0.1 mg/kg 3个浓度进行3次空白样品添加试验,白菜的平均回收率为89.49%～118.55%,变异系数为3.0%～5.7%.符合农药残留技术测定要求.     

化工厂含氰化物废水监测控制系统的研制

介绍化工厂含氰化物废水监测控制系统的组成及工作过程，给出了基于89C52单片机监测控制系统的硬件及软件实现方案，该系统能够准确控制含氰化物废水的处理质量，运行结果表明，该设计方案合理可靠。     

苹果及土壤中的螺螨酯残留分析方法

研究并建立了用乙腈提取,弗罗里硅土净化,气相色谱-电子捕获检测器检测苹果和土壤中螺螨酯残留的分析方法.螺螨酯在苹果和土壤中的添加回收率分别为82.11%～100.36%和79.27%～94.55%,相对标准偏差分别为0.92%～6.84%和1.89%～8.57%.该方法的准确度、精确度以及灵敏度均达到农药残留分析的要求.     

基于虚拟仿真实验的氰化浸金教学研究

氰化浸金实验由于实验原料包含剧毒化学品而无法向本科生开放实验室实验。通过引入虚拟仿真实验教学,打破了这个壁垒。主要介绍了氰化浸金虚拟仿真教学实验的设计思路、系统实现以及仿真实验的教学实现过程,通过对学生学习动机、课程体验、学习效果3个方面的调查客观地进行了系统评估,评估结果显示学生普遍能通过该软件完成氰化浸金实验的学习,获得对氰化浸金实验的原理、流程及主要参数影响方面较好的理解。     

流动注射-分光光度法测定水中氰化物

使用流动注射(FIA)-分光光度法测定水中的氰化物的含量,并与传统分光光度法的分析结果进行比对。实验证明流动注射(FIA)-分光光度法操作简便、线性好,灵敏度、精密度、准确度都能符合分析工作要求。检出限为0.2μg/L,适用于水中微量氰化物的检测。分析频率为每小时30个样品,特别适合大批样品的测定。     

Kinetic Parameters of Gold Dissolution in Cyanide Solutions: The Effect of Complex Cyanide Ions of Mercury

The kinetics of the gold dissolution in cyanide solutions is studied at constant values of the coverage () of the gold surface by mercury atoms. The constancy of is ensured by maintaining an identical value of the duration (t) of contact of electrode with solution (after renewing its surface by cutting off a thin surface layer of metal) at a potential of –1.3 V, at which the discharge of mercury ions is limited by their diffusion to the electrode. At t = const kinetic dependences of the gold dissolution process correspond to the Tafel equation. Effective values of exchange current i ₀, transfer coefficient , and reaction order by cyanide ions P are determined. With increasing value of their magnitude increases from values 10^–5 A cm^–2, 0.1, and 0.17 that are characteristic of purely cyanide solutions (composition 0.1 M KCN, 0.1 M KOH, and 0.01 M KAu(CN)₂) to i ₀ 2 × 10^–4 A cm^–2, = 0.46, and P 1 at t = 270 s. These results are compared with the data obtained earlier during similar investigations in solutions containing thallium, lead, and bismuth. Common and individual features in the behavior of mercury-containing electrolytes are revealed. It is shown that the possible mechanism of the acceleration of the gold dissolution process in the presence of catalytically active atoms, which had been proposed in these works, may be used also for explaining the action of mercury atoms on this process.     

Cyanide Biodegradation by Trichoderma harzianum and Cyanide Hydratase Network Analysis

Cyanide is a poisonous and dangerous chemical that binds to metals in metalloenzymes, especially cytochrome C oxidase and, thus, interferes with their functionalities. Different pathways and enzymes are involved during cyanide biodegradation, and cyanide hydratase is one of the enzymes that is involved in such a process. In this study, cyanide resistance and cyanide degradation were studied using 24 fungal strains in order to find the strain with the best capacity for cyanide bioremediation. To confirm the capacity of the tested strains, cyano-bioremediation and the presence of the gene that is responsible for the cyanide detoxification was assessed. From the tested organisms, Trichoderma harzianum (T. harzianum) had a significant capability to resist and degrade cyanide at a 15 mM concentration, where it achieved an efficiency of 75% in 7 days. The gene network analysis of enzymes that are involved in cyanide degradation revealed the involvement of cyanide hydratase, dipeptidase, carbon–nitrogen hydrolase-like protein, and ATP adenylyltransferase. This study revealed that T. harzianum was more efficient in degrading cyanide than the other tested fungal organisms, and molecular analysis confirmed the experimental observations.     

Thermal Decomposition of Trialkyl/Arylphosphine Gold(I) Cyanide Complexes

Combined TG/DTA techniques have been used to study the thermal decomposition of R₃PAuCN (where Ris ethyl, cyclohexyl, o-tolyl, m-tolyl, p-tolyl, allyl, cyanoethyl,1-naphthyl and phenyl) complexes. It was observed that all of these complexes underwant decomposition cum redox reactions in the range of 200–600oC with evolution of both transligands, which are phosphine and cyanide, leaving metallic gold as a residue. The thermal decomposition of o-Tol₃PAuCN has revealed that this is a stepwise process. In the first step decomposition takes place with evolution of phosphine and generation of AuCN, which in second step undergoes a redox reaction to produce metallic gold. The DTA curves have also confirmed these results. This revised version was published online in July 2006 with corrections to the Cover Date.     

Microdetermination of Cyanide

Abstract

A volumetric procedure is described for the micro-determination of cyanide. Small amounts of cyanide can be estimated even in presence of chloride if it is present in the electrolytic bath. N-Bromosuccinimide (NBS) is used to quantitatively oxidized cyanide to cyanate. The end point is reached when the rose red color of the bordeaux red is changed to distinct yellow. From 1–6 mg. of cyanide were analyzed with an average relative standard deviation of about 0.66%.     

Effect of Lead Ions on the Kinetics of Gold Deposition from Cyanide Electrolytes

The depolarization of the gold electrodeposition in the presence of lead ions depends on their concentration and the duration of electrode contact with solution preceding a potential scan in an extremum fashion. At constant coverages of the gold surface by lead adatoms , the process rate depends on the overvoltage in accord with the Tafel equation. Effective values of the exchange current i ₀ and transfer coefficient increase with from i ₀ 3 × 10^–5 A cm^–2 and = 0.23 in pure solutions to 3 × 10^–4 A cm^–2 and 0.53 at 0.4. The reaction order by cyanide ions is independent of and equals nearly –0.9. Effects of lead adatoms on the kinetics of cathodic and anodic processes are compared and the obtained data may be brought to conformance given that their mechanisms in pure solutions differ and converge in the presence of lead adatoms.     

An Efficient Probe for Rapid Detection of Cyanide in Water at Parts per Billion Levels and Naked‐Eye Detection of Endogenous Cyanide

A new molecular probe based on an oxidized bis‐indolyl skeleton has been developed for rapid and sensitive visual detection of cyanide ions in water and also for the detection of endogenously bound cyanide. The probe allows the “naked‐eye” detection of cyanide ions in water with a visual color change from red to yellow (Δλ_max=80 nm) with the immediate addition of the probe. It shows high selectivity towards the cyanide ion without any interference from other anions. The detection of cyanide by the probe is ratiometric, thus making the detection quantitative. A Michael‐type addition reaction of the probe with the cyanide ion takes place during this chemodosimetric process. In water, the detection limit was found to be at the parts per million level, which improved drastically when a neutral micellar medium was employed, and it showed a parts‐per‐billion‐level detection, which is even 25‐fold lower than the permitted limits of cyanide in water. The probe could also efficiently detect the endogenously bound cyanide in cassava (a staple food) with a clear visual color change without requiring any sample pretreatment and/or any special reaction conditions such as pH or temperature. Thus the probe could serve as a practical naked‐eye probe for “in‐field” experiments without requiring any sophisticated instruments.     

Determination of Free Cyanide in Water by Released Flourescence of a Dissociated Ternary Complex

Abstract

A flourometric procedure for the analysis of free cyanide is described. The method is based on the dissociation of a ternary complex of silver-1, 10-phenanthroline-tetrabromofluorescein by cyanide to produce a fluorescent product. The fluorescence intensity is found to be directly proportional to the cyanide concentration. The method can reliably detect 0.02 μg/mL cyanide.