A modified ninhydrin micro-assay for determination of total cyanogens in plants

Evaluation of Hydrogen Cyanide in the Blood of Fire Victims Based on the Kinetics of the Reaction with Ninhydrin

An original kinetic spectrophotometric procedure was developed for the determination of hydrogen cyanide (HCN) in the whole blood of fire victims. Cyanide poisoning by smoke inhalation is common in forensic medicine, but the blood HCN of fire victims has not been studied in detail so far. In this research project, we developed a simple, fast, sensitive, and selective quantification method for both free and metabolized HCN based on the kinetics of cyanide reaction with ninhydrin. The method was linear in range, from 0.26 to 2.6 μg mL−1, with a coefficient of determination of r = 0.994. A high molar absorptivity of 4.95 × 105 L mol−1 cm−1 was calculated under the reaction conditions. The limit of quantification was 0.052 μg mL−1; the detection limit was 0.012 μg mL−1 and the standard error was ±2.7%. This micro method proved to be accurate, sensitive, and selective and has been successfully applied to the analysis of blood samples, allowing rapid monitoring of blood cyanide in several fire victims.

Toxic Blood Hydrogen Cyanide Concentration as a Vital Sign of a Deceased Room Fire Victim-Case Report

Carbon monoxide (CO) and hydrogen cyanide (HCN) are two common toxic products of combustion. HCN concentrations of fire victims are not routinely determined in most legal medicine services in Romania. We present the case of a room fire victim in which we evaluated the concentrations of HCN and carboxyhemoglobin (COHb), their contribution to the mechanism of death, and the possibility that HCN concentration can be interpreted as vital sign. COHb was determined by spectrophotometry. HCN was spectrophotometrically determined with ninhydrin in postmortem blood samples after its removal with 20% phosphoric acid and uptake into a solution of potassium carbonate. The presence of ethyl alcohol was determined by gas chromatography. The COHb concentration was 6.15%, while the blood HCN concentration was 1.043 µg × mL⁻¹ and the total HCN was 1.904 µg × ml⁻¹. A blood alcohol content of 4.36 g‰ and a urine alcohol content of 5.88 g‰ were also found. Although the fire produced a considerable amount of soot, and there were signs of inhalation of soot particles, the COHb level cannot be interpreted as a vital sign. Toxic concentrations of HCN and total HCN can be interpreted as a vital sign and indicates a contributive effect of HCN in the mechanism of death.

Hydrogen cyanide and carboxyhemoglobin assessment in an open space fire-related fatality

Hydrogen cyanide (HCN) can be a major contributory factor in death from fire-related inhalation injury. Although carbon monoxide (CO) is considered the lethal agent of smoke in fires, its liability as a cause of death is sometimes debatable. The purpose of this report is to present the case of an 80-year-old man with locomotor disabilities who died due to an open space fire of vegetation debris and household waste in his yard. We evaluated here the concentrations of HCN and carboxyhemoglobin (COHb) and their contribution to the mechanism of death. In addition, the risk factors and the contributing effect of the factors that compose the complex toxic environment that develops in fires were discussed. COHb was determined by spectrophotometry as recommended by Katsumata et al. in 1982. HCN was determined with ninhydrin in postmortem blood samples after removal with 20% phosphoric acid and capture in a potassium carbonate solution. A toxic concentration of 1.3 μg ml^-1 HCN and a lethal COHb level of 73.7% were determined in the blood samples. Although death was mainly attributed to CO poisoning and extremely severe burns in this open space burning case, the additive effect of HCN in the mechanism of death was also highlighted. The results suggested the possibility that the man's clothing may have played an important role in the production of HCN in this open space fire, as well as other types of garbage that were burned.

Determination of cyanide in bamboo shoots by microdiffusion combined with ion chromatography-pulsed amperometric detection

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 parameters were optimized including hydrolysis systems, temperature, time, and so on. Under the optimum conditions, the linear range of the calibration curve for cyanide was 0.2-200.0 µg kg^-1 with satisfactory correlation coefficients of 0.9996 and the limit of detection was 0.2 µg kg^-1 (S/N = 3). The spiked recovery range was from 92.8 to 98.6%. The intra-day and inter-day relative standard deviations of cyanide were 2.7-14.9% and 3.0-18.3%, respectively. This method was proved to be convenient in operation with high sensitivity, precision and accuracy, and was successfully applied in the determination of cyanide in bamboo shoot samples.

Cyanides in the environment-analysis-problems and challenges

Cyanide toxicity and their environmental impact are well known. Nevertheless, they are still used in the mining, galvanic and chemical industries. As a result of industrial activities, cyanides are released in various forms to all elements of the environment. In a natural environment, cyanide exists as cyanogenic glycosides in plants seeds. Too much consumption can cause unpleasant side effects. However, environmental tobacco smoke (ETS) is the most common source of cyanide. Live organisms have the ability to convert cyanide into less toxic compounds excreted with physiological fluids. The aim of this paper is to review the current state of knowledge on the behaviour of cyanide in the environment and its impact on the health and human life.

Dietary resources shape the adaptive changes of cyanide detoxification function in giant panda (Ailuropoda melanoleuca)

The functional adaptive changes in cyanide detoxification in giant panda appear to be response to dietary transition from typical carnivore to herbivorous bear. We tested the absorption of cyanide contained in bamboo/bamboo shoots with a feeding trial in 20 adult giant pandas. We determined total cyanide content in bamboo shoots and giant panda’s feces, levels of urinary thiocyanate and tissue rhodanese activity using color reactions with a spectrophotometer. Rhodanese expression in liver and kidney at transcription and translation levels were measured using real-time RT-PCR and immunohistochemistry, respectively. We compared differences of rhodanese activity and gene expressions among giant panda, rabbit (herbivore) and cat (carnivore), and between newborn and adult giant pandas. Bamboo shoots contained 3.2 mg/kg of cyanide and giant pandas absorbed more than 65% of cyanide. However, approximately 80% of absorbed cyanide was metabolized to less toxic thiocyanate that was discharged in urine. Rhodanese expression and activity in liver and kidney of giant panda were significantly higher than in cat, but lower than in rabbit (all P < 0.05). Levels in adult pandas were higher than that in newborn cub. Phylogenetic analysis of both nucleotide and amino acid sequences of the rhodanese gene supported a closer relationship of giant panda with carnivores than with herbivores.