Detection Of Thiocyanate Research Articles

Detection of thiocyanate in postmortem blood of a fatal potassium thiocyanate-poisoning patient using gas chromatography-mass spectrometry.

Thiocyanate is an inorganic compound used in industrial applications. Here, we report a case of suicidal death due to acute thiocyanate overdose. A 44-year-old man who consumed an unknown amount of thiocyanate solution was transferred to the emergency room and died two hours after admission. An autopsy was performed two days after death. General toxicological analysis of blood using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry found no drug or alcohol. Quantification using GC-MS post-derivatization with pentafluorobenzyl bromide revealed 2,290 and 1,920 mg/L of thiocyanate in the heart and femoral blood samples, respectively. Thus, the cause of death was attributed to thiocyanate overdose. This study provides useful information for the interpretation of thiocyanate-related fatalities.

On-chip absorption spectroscopy enabled by graded index fiber tips.

This paper describes the design and characterization of miniaturized optofluidic devices for sensing based on integrating collimating optical fibers with custom microfluidic chips. The use of collimating graded-index fiber (GIF) tips allows for effective fiber-channel-fiber interfaces to be realized when compared with using highly-divergent standard single-mode fiber (SMF). The reduction in both beam divergence and insertion losses for the GIF configuration compared with SMF was characterized for a 10.0 mm channel. Absorption spectroscopy was demonstrated on chip for the measurement of red color dye (Ponceau 4R), and the detection of thiocyanate in water and artificial human saliva. The proposed optofluidic setup allows for absorption spectroscopy measurements to be performed with only 200 µL of solution which is an order of magnitude smaller than for standard cuvettes but provides a comparable sensitivity. The approach could be integrated into a lab-on-a-chip system that is compact and does not require free-space optics to perform absorption spectroscopy.

Can excreted thiocyanate be used to detect cyanide exposure in live reef fish?

Cyanide fishing, where a solution of sodium or potassium cyanide is used to stun reef fish for easy capture for the marine aquarium and live fish food trades, continues to be pervasive despite being illegal in many countries and destructive to coral reef ecosystems. Currently, there is no easy, reliable and universally accepted method to detect if a fish has been exposed to cyanide during the capture process. A promising non-invasive technique for detecting thiocyanate ions, the metabolic byproduct excreted by exposed fish, has been reported in the literature. In an effort to validate this method, four cyanide exposure studies on Amphiprion ocellaris (common clownfish) were carried out over three years. Fish were either exposed to the same (25 ppm) or twice the concentration (50 ppm) as the previsouly published method. Over 100 water samples of fish exposed to cyanide were analyzed by reverse phase HPLC with a C30 column treated with polyethylene glycol and UV detector operating at 220 nm. No thiocyanate was detected beyond the analytical standards and positive controls prepared in seawater. As an alternate means of detecting thiocyanate, water samples and thiocyanate standards from these exposures were derivatized with monobromobimane (MBB) for LC-MS/MS analysis. Thiocyanate was detected in standards with concentrations as low as 0.6 μg/L and quantified to 1 μg/L, but thiocyanate could not be detected in any of the water samples from fish exposed to cyanide with this method either, confirming the HPLC results. Further, we calculated both the mass balance of thiocyanate and the resultant plausible dosage of cyanide from the data reported in the previously published method. These calculations, along with the known lethal dosage of cyanide, further suggests that the detection of thiocyanate in aquarium water is not a viable method for assessing fish exposure to cyanide.

Impedimetric and electrocatalytic properties of nanostructured iron(II) phthalocyanine at pyrolytic graphite electrode

The electron transfer behaviour of nanostructured iron(II) phthalocyanine (nanoFePc) at edge plane pyrolytic graphite electrodes (EPPGEs) has been investigated using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). This study proves that the nanoFePc-based electrode exhibits faster heterogeneous electron transfer constant, k app (about a magnitude higher) than the bulk FePc. In addition, the nanoFePc exhibited enhanced electrocatalytic properties towards the detection of thiocyanate and nitrite in aqueous solutions compared to the bulk FePc counterpart. The results suggest that the nanoFePc could serve as a powerful organometallic functional material for the development of sensors and electrocatalytic devices.

Surface electrochemistry of iron phthalocyanine axially ligated to 4-mercaptopyridine self-assembled monolayers at gold electrode: Applications to electrocatalytic oxidation and detection of thiocyanate

Surface electrochemical behaviour of a self-immobilised iron phthalocyanine (FePc) ultrathin film, via axial ligation reaction, onto a preformed 4-mercaptopyridine self-assembled monolayer on gold electrode has been described. Electrochemical evidence for the sensor clearly suggested surface-confined, flat “umbrella”-oriented and densely-packed monolayer film structure. The proposed electrochemical sensor exhibited good catalytic activity towards the oxidation of thiocyanate in pH 4.0 medium over a linear range of three decades of concentration (ca. 10 −6–10 −3 mol dm −3) with a detection limit in the order of ∼10 −7 mol dm −3. The sensor exhibited useful potential for the analysis of thiocyanate in human urine and saliva samples. The advantageous properties of this type of electrode as a sensor for thiocyanate lie in its ease of fabrication, excellent catalytic activity, stability, sensitivity and simplicity.

Mn(III)—porphyrin‐based thiocyanate‐selective membrane electrodes: Characterization and application in flow injection determination of thiocyanate in saliva

AbstractThe response properties of a new thiocyanate‐selective solvent‐polymeric membrane electrode are reported. The membrane contains (5,10,15,20‐tetrakis(2,4,6‐triphenylphenyl)porphyrinato)manganese(III) chloride (Mn[TPPP]CI) in a plasticized polyvinyl chloride matrix. The electrode deviates from the Hofmeister selectivity pattern by responding to thiocyanate preferentially over inorganic anions (perchlorate, chloride, iodide, and bromide) and several organic anions often present in biological samples (ascorbate, citrate, urate, and salicylate). The performance of this electrode as an ion‐selective detector in a low‐dispersion, flow‐injection system is also evaluated. While selectivity in such a nonequilibrium flow arrangement is found to be somewhat different than that observed under equilibrium conditions, the electrode's response and selectivity is still adequate to allow for measurement of thiocyanate in biological samples. This application is demonstrated via the flow‐injection analysis (FIA) detection of thiocyanate in 22 human saliva samples with good correlation to a classical colorimetric method (r = 0.981).

Continuous-flow (Autoanalyzer I) analysis for plasma thiocyanate as an index to tobacco smoking.

Abstract We describe a procedure for determining thiocyanate in plasma with a Technicon AutoAnalyzer I, modified with a 50-mm tubular flow cell to increase the sensitivity of thiocyanate detection. The procedure is suitable for distinguishing cigarette smokers from non-smokers, the mean for smokers being 151 (SD 43) micromol/L and for non-smokers 62 (SD 19) micromol/L.

Continuous-flow (Autoanalyzer I) analysis for plasma thiocyanate as an index to tobacco smoking.

We describe a procedure for determining thiocyanate in plasma with a Technicon AutoAnalyzer I, modified with a 50-mm tubular flow cell to increase the sensitivity of thiocyanate detection. The procedure is suitable for distinguishing cigarette smokers from non-smokers, the mean for smokers being 151 (SD 43) micromol/L and for non-smokers 62 (SD 19) micromol/L.

Detection of thiocyanate and dissolution of silver halides

This procedure will detect the presence of 1 mg of I-, Br-, Cl-, or SCN- in any mixture containing up to 100 mg of each of the other ions.

The Cobalt-Thiocyanate Reaction for the Detection of Cobalt and Thiocyanate

1. Alkali-thiocyanate is a sensitive reagent for the detection of cobalt in presence of 40 to 50% acetone. Ferric iron can be made harmless by addition of an excess of fluoride. A procedure has been developed for the application of the reaction as a micro-and macro test for cobalt. Cupric copper gives a sensitive reaction and must be removed. The thiocyanate is preferable to cyanate as a reagent. 2. A procedure has been described for the micro detection of thiocyanate by evaporating a drop of the solution to be tested with a small drop of cobalt sulfate and moistening the residue with acetone. The formation of a distinctly green solution indicates the presence of thiocyanate. Nitrite interferes.