Headspace single-drop microextraction and cuvetteless microspectrophotometry for the selective determination of free and total cyanide involving reaction with ninhydrin.
Abstract Headspace single-drop microextraction has been used for the determination of cyanide with ninhydrin in combination with fibre-optic-based cuvetteless microspectrophotometry which accommodates sample volume of 1 μL placed between the two ends of optical fibres, and has been found to avoid salient drawbacks of batch methods. This method involved hydrocyanic acid formation in a closed vial, and simultaneous extraction and reaction with 2 μL drop of ninhydrin in carbonate medium suspended at the tip of a microsyringe needle held in the headspace of the acidified sample solution. The method was linear in range 0.025–0.5 mg L−1 of cyanide. The headspace reaction was free from the interference of substances, e.g., thiocyanate, hydrazine sulphate, hydroxylammonium chloride and ascorbic acid. Sulphide was masked by cadmium sulphate, nitrite by sulphamic acid, sulphite by N-ethylmaleimide, and halogens by ascorbic acid. The limit of detection was found to be 4.3 μg L−1 of cyanide which was comparable to existing most sensitive methods for cyanide. However, the present method is far more simple. The method was applied to acid-labile and metal cyanides complexes by treatment with sulphide when metal sulphides were precipitated setting cyanide ion free, and to iron(II) and (III) cyanide complexes by their decomposition with mercury(II), the mercury(II) cyanide formed was then determined. These pre-treatment methods avoided cumbersome pre-separation of cyanide by methods such as distillation or gas diffusion. The overall recovery of cyanide in diverse samples was 97% with RSD of 3.9%.
#2Ian C. Denton(ANU: Australian National University)H-Index: 9
Abstract In 2005 a simple wetting method was developed that reduced total cyanide content of cassava flour 3–6-fold. The method involved spreading wet flour in a thin layer and standing in the shade for five hours to allow evolution of HCN gas. We found that breakdown of linamarin catalysed by linamarase to acetone cyanohydrin, followed by its spontaneous decomposition to HCN and acetone was greatly increased by standing the wet flour in the sun. Treatment for two hours in the sun gave the same ...
Abstract A novel, simple and low cost method for the determination of nitrite using headspace single-drop microextraction and cuvetteless ultraviolet–visible micro-spectrophotometry is described. A Griess reagent-containing aqueous microdrop exposed to the headspace was used as extractant of the volatile nitrogen oxides generated from nitrite by direct acidification of the aqueous sample. Experimental parameters affecting the headspace single-drop microextraction performance such as composition ...
#1Ornthida Sae-Khow(NJIT: New Jersey Institute of Technology)H-Index: 11
#2Somenath Mitra(NJIT: New Jersey Institute of Technology)H-Index: 56
Unlike thermal processes such as distillation, pervaporation relies on the relative rates of solute permeation through a membrane and is a combination of evaporation and gas diffusion. The analytical pervaporation systems consist of a membrane module suitable for liquid sample introduction and a vacuum (or a sweeping gas) on the permeate side. It has been used in a wide range of applications including the analysis of various organic and inorganic compounds, and sample concentration. It has been ...
The combination of liquid-phase microextraction and microvolume UV–vis spectrophotometry has been applied to the determination of iodate in natural water samples. The method is based on the reduction of iodate into vapor iodine and extraction of this volatile onto a single drop of N,N′-dimethylformamide. The following derivatization reaction was employed: IO3− + 5I− + 6H+ → 3I2 + 3H2O Optimum conditions employed for iodate determination were as follows: 2.5 μL N,N′-dimethylformamide exposed to t...
Last. T. N. Guru Row(IISc: Indian Institute of Science)H-Index: 34
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Novel chromogenic thiourea based sensors 4,4'-bis-[3-(4-nitrophenyl) thiourea] diphenyl ether 1 and 4,4'-bis-[3-(4-nitrophenyl) thiourea] diphenyl methane 2 having nitrophenyl group as signaling unit have been synthesized and characterized by spectroscopic techniques and X-ray crystallography. The both sensors show visual detection, UV-vis and NMR spectral changes in presence of fluoride and cyanide anions in organic solvent as well as in aqueous medium. The absorption spectra indicated the form...
Abstract Headspace single-drop microextraction has been investigated for the determination of chloride in conjunction with fibre optic-based cuvetteless micro-spectrophotometry which accommodates sample volume of 1 μL placed between the two ends of optical fibres. Method has been evolved for the determination of 0.025–4 mg L −1 of chloride involving its oxidation with permanganate in sulphuric acid medium, and reaction of chlorine with 2 μL drop of starch-iodide reagent suspended at the tip of m...
Abstract In this work, headspace-single-drop microextraction has been used in combination with microvolume UV–vis spectrophotometry to enhance the determination of trimethylamine-nitrogen (TMA-N) in fish samples. TMA-N is often used for monitoring fish freshness, but due to the low analytical sensitivity usually achieved, its determination must be performed after certain time of storage in some fish species. The proposed methodology, based on the extraction and subsequent complexation of volatil...
Last. M.S. El-Shahawi(KAU: King Abdulaziz University)H-Index: 23
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A simple, fast, low cost and sensitive direct β-correction spectrophotometric assay of cyanide ions based on its reaction with the reagent 4-hydroxy-3-(2-oxoindolin-3-ylideneamino)-2-thioxo-2H-1,3-thiazin-6(3H)-one, abbreviated as HOTT in aqueous media of pH 7-10 is described. The electronic spectrum of the produced brown-red colored species showed well defined and sharp peak at λmax = 466 nm. The effective molar absorptivity for the produced cyano compound was 2.5 × 104 L mol-1 cm-1. Beer's law...
Last. Ming Guo(DUT: Dalian University of Technology)H-Index: 2
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Abstract A new method is reported for the simultaneous derivatization and extraction of free cyanide in biological samples using home-made hollow fiber-protected headspace liquid-phase microextraction (HF-HS-LPME) followed by capillary electrophoresis (CE) determination. The acceptor phase containing Ni(II)-NH3 (as derivatization agent), sodium carbonate and ammonium pyromellitate (as internal standard) is held within a hollow fiber membrane, affixed to a syringe needle and immersed in the heads...
Corrin-based chemosensors allow the rapid and selective colorimetric detection of endogenous biological cyanide. The color change from orange to violet can be easily observed with the “naked eye” (Δλmax = 51 nm). The methodology works directly in the biological matrix without time-consuming sample pretreatment and the use of special reaction conditions. It was possible to study the enzymatic release of cyanide from its biological precursor linamarin with diffuse reflectance UV−visible (DRUV−vis)...
In this study, a new chemosensor IDTTH for rapid detection of cyanide (CN─) based on 6,6,12,12-Tetrakis(4-hexylphenyl)-6,12-dihydrodithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]di- thiophene-2,8-dicarboxaldehyde-hemicyanine conjugate has been developed. The 6,6,12,12-tetrakis(4-hexylphenyl)-6,12-dihydrodithi-eno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]dithiophene was served as a signal unit and hemicyanine as a recognition unit. This probe shows high selectivity towards CN─ ions among tested ...
Abstract Single-drop microextraction (SDME) has been recognized as one of the simple miniaturized sample preparation tools for the isolation and preconcentration of several analytes from a complex sample matrix. In this review, we explored the applications of SDME coupled with various analytical techniques (spectroscopy, chromatography, and mass spectrometry) for the analysis of organic molecules, inorganic ions, and biomolecules from various sample matrices including food, environmental, clinic...
In this paper, a flexible and efficient nano-reinforced polymer inclusion membrane (PIM) was fabricated and used for cyanide (CN−) extraction from water samples. Aliquat 336 (a liquid anion exchanger) was embedded in poly(vinyl chloride) (PVC) support as the extractant. Mg-Al-CO3 layered double hydroxide (LDH) with high surface area and anion exchange ability was applied to promote the extraction efficiency of PIM. A PIM comprising 56% PVC, 40% Aliquat 336, and 4% Mg-Al-CO3 LDH showed the best e...
Abstract In recent years, liquid phase microextraction (LPME) as a solvent–minimized and microscale implementation of sample pretreatment procedure of liquid–liquid extraction has been introduced and obtained great attention among the researchers due to its simplicity, low cost, rapidity, and efficiency. Developments have led to different approaches of LPME such as headspace mode of liquid phase microextraction (HS mode of LPME) which is used in the cases of volatile and semi–volatile analytes. ...
#1Mohammad Saraji(IUT: Isfahan University of Technology)H-Index: 30
#2Neda Bagheri(IUT: Isfahan University of Technology)H-Index: 3
Abstract A simple, cost-effective, instrumental free and user-friendly analytical method based on the combination of paper-based headspace extraction and digital scanning image analysis was developed for the sensitive detection of cyanide in water and wastewater samples. The method relied on chloramine-T/pyridine-barbituric acid reaction, which is a well-known process for measuring cyanide in standard analytical methods. During the reaction, cyanide was converted to cyanogen chloride, which was ...
A practical method for the determination of cyanide in bamboo shoots has been developed using microdiffusion preparation integrated with ion chromatography–pulsed amperometric detection (IC-PAD). Cyanide was released from bamboo shoots after Conway cell microdiffusion, and then analysed by IC-PAD. In comparison with the previously reported methods, derivatization and ion-pairing agent addition were not required in this proposed microdiffusion combined with IC-PAD method. The microdiffusion param...
Last. M.S. El-Shahawi(KAU: King Abdulaziz University)H-Index: 23
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Abstract A simple, low cost and efficient headspace sorptive solid phase microextraction (HS-SPME) method for determination of cyanide has been developed. The system comprises of a glass tube with two valves and a moveable glass slide fixed at its centre. It includes an acceptor phase polyurethane foam treated mercury (II) dithizonate [Hg(HDz)2–PUF] complex fixed inside by a septum cap in a cylindrical configuration (5.0 cm length and 1.0 cm diameter). The extraction is based upon the contact of...
#2Marius Zaharia(UAIC: Alexandru Ioan Cuza University)H-Index: 5
Last. Robert Gradinaru(UAIC: Alexandru Ioan Cuza University)H-Index: 6
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ABSTRACTCyanide is an extremely severe poison that has been raising concerns and controversies regarding its toxic effects on humans and the environment. A short-term human exposure to elevated levels can induce coma or death. Toxic effects occur at blood cyanide concentrations of 0.05 mg/dL, while death can occur at levels of 0.3 mg/dL. Numerous law and systems regulate cyanide levels in various environments. To exemplify, the maximum contamination limit imposed by United States Environmental P...
Last. Shize Jia(Shanxi Teachers University)H-Index: 2
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A flow injection chemiluminescence (FI–CL) method was developed for the determination of cyanide (CN−) based on the recovered CL signal by Cu2+ inhibiting a glutathione (GSH)-capped CdTe quantum dot (QD) and hydrogen peroxide system. In an alkaline medium, strong CL signals were observed from the reaction of CdTe QDs and H2O2, and addition of Cu2+ could cause significant CL inhibition of the CdTe QDs–H2O2 system. In the presence of CN−, Cu2+ can be removed from the surface of CdTe QDs via the fo...
An ion chromatographic method for the quantitative determination of free cyanide in bottled natural mineral waters were measured in terms of selectivity, linearity, the limit of detection, limit of quantification, repeatability, precision, and accuracy. Chromatographic separation of free cyanide ions was accomplished with an anion-exchange column and detected by pulsed amperometric detection with a silver working electrode. The method was found to be selective, linear (r2 = 0.999) at a concentra...
