Synthesis of Symmetrical Acetophenone Azine Derivatives as Colorimetric and Fluorescent Cyanide Chemosensors

Cyanide is a highly toxic anion and poison to the environment. Therefore, fast, effective, and efficient analysis methods to detect cyanide are needed. Herein, symmetrical chemosensor of 2’-hydroxy acetophenone azine (1) and 2’,4’-dihydroxy acetophenone azine (2) has been synthesized tested as colorimetric and fluorescent cyanide chemosensor. The azines were produced from the condensation of acetophenone derivatives with hydrazine hydrate in ethanol under reflux or ultrasonic irradiation methods. Colorimetric and fluorescent chemosensor tests showed selectivity to acetate and cyanide anions in DMSO. The limit of detection (LOD) for colorimetric measurement of cyanide anion was 9.68×10–4 M for compound (1) and 9.63×10–5 M for compound (2), while the fluorescent method showed 15.90×10–4 M for compound (1) and 8.95×10–5 M for compound (2), respectively. In addition, test paper-strips containing sensor 2 indicated noticeable results for 'naked eye' detection of cyanide in an aqueous medium.

“Naked-eye” detection of CN− from aqueous phase and other extracellular matrices: an experimental and theoretical approach mimicking the logic gate concept

Selective and real-field detection of a toxic anion (CN−) from aqueous and extracellular matrices by a cost-effective chemosensor.

Luminescent lanthanide metal–organic frameworks for chemical sensing and toxic anion detection

A co-doped lanthanide metal–organic framework (LnMOF) consisting of anion affinity sites exhibits self-calibrating, high distinguishable and stable photoluminescent signals for detecting toxic anions.

Expert opinion: fomepizole may ameliorate the need for hemodialysis in methanol poisoning

Fomepizole is now the antidote of choice in methanol poisoning. The use of fomepizole may also change the indications for hemodialysis in these patients. We have addressed this change in a review of articles on methanol poisonings. Review of the literature (through PubMed®) combined with our own experiences from two recent methanol outbreaks in Estonia and Norway. The efficiency of dialysis during fomepizole treatment was reported in only a few reports. One recent study challenged the old indications, suggesting a new approach with delayed or even no hemodialysis. Methanol-poisoned patients on fomepizole treatment may be separated into two categories: 1) The critically ill patient, with severe metabolic acidosis (base deficit >15 mM) and/or visual disturbances should be given buffer, fomepizole and immediate hemodialysis: dialysis removes the toxic anion formate, and assists in correcting the metabolic acidosis, thereby also reducing formate toxicity. The removal of methanol per se is not important in this setting because fomepizole prevents further production of formic acid. 2) The stable patient, with less metabolic acidosis and no visual disturbances, should be given buffer and fomepizole. This treatment allows for the possibility to delay, or even drop, dialysis in this setting, because patients will not develop more clinical features from methanol poisoning when fomepizole and bicarbonate is given in adequate doses. Indications and triage for hemodialysis in methanol poisonings should be modified. Delayed hemodialysis or even no hemodialysis may be an option in selected cases.

A Study of the Relative Toxicity of Anions, with Polycelis Nigra as Test Animal

A brief review is given of existing knowledge regarding the physiological effects of anions, and literature dealing with their relative toxicity. The degree of toxicity of twenty-seven anions to Polycelis nigra (Müller) has been assessed, by determining in each case the molar concentration the animal survives for 48 hr. at 15-18° C. On this basis their order of increasing toxicity is as follows; commas separate ions of similar degree of toxicity: Cl<ClO3, acetate, Br <CO3 <tartrate <S2O3 <SO4, SO3 <I, NO3 <PO4, BO3 <BrO3 <citrate <CNS, C2O4 <AsO4 <CrO3 <IO3 <F <Fe(CN)6, Fe(CN)5NO <NO2, CN <S<OH. Generally speaking anions are very much less toxic than cations. Even the most toxic anion (OH) is far less toxic than ionic copper, silver or gold. The respiration rate of Polycelis is heavily depressed by cyanide, but the survival time is three days or longer, as long as the respiration rate is not less than about 16% of the normal value. With further depression the survival time shortens rapidly, and at 9% normal is under 4 hr. The normal respiration rate of Polycelis nigra is 0.165 c.c. O2/g./hr. This is not very much less than that of the trout. Polycelis is considerably the more resistant to cyanide. This is probably connected with its capability of surviving very many hours in water containing a very reduced supply of oxygen.