An unusual case of methemoglobinemia resulting from self-administration of nitrobenzene in a psychiatric patient

Nitrobenzene, when consumed in large enough doses, can cause methemoglobinemia. By reducing oxygen unloading and oxygen binding, methemoglobinemia reduces oxygen delivery. This is a case of 55-year-old man who is a known case of psychiatric disorder was brought to the emergency room with an alleged history of deliberate consumption of nitrobenzene liquid approximately 10 mL in the morning of the day at his residence. He also instilled 2 drops in the right ear and was taken to a private hospital where the initial management with gastric lavage, multidose activated charcoal and methylene blue was given. He was then referred to the government tertiary care setting for further management. Prompt intravenous methylene blue treatment increases PaO2 in patients with methemoglobinemia.

Research progress on detection methods for nitrobenzene compounds in air / 中国职业医学

@#Abstract: Nitrobenzene compounds (NBCs) are widely used in the world. It has 40 isomers such as nitrobenzene, dinitrobenzene and nitrotoluene, that are highly toxic and difficult to degrade and can cause harm to human health in different degrees. At pres⁃ ent, there is no unified standard method and occupational exposure limit for the detection of NBCs in the air. In terms of sampling medium, solid adsorption tube is mostly used for trapping vapor state NBCs, and filter membrane and solid adsorption tube are mostly used in series for sampling coexist NBCs in vapor state and aerosol state. In the detection methods, gas chromatography and liquid chromatography are common, and ultraviolet spectrophotometry, Raman spectroscopy, ion migration spectrometry and some other rapid response methods and technologies are also used in the detection of NBCs. In the detection of NBCs by gas chro⁃ matography, capillary column separation is commonly used, and the main detectors are flame ionization detector, electron capture detector and mass spectrometry detector. It is of practical significance to establish a method with high sensitivity, strong practica⁃ bility, convenient operation, and can simultaneously collect and detect a variety of NBCs in different states.

Chloro-nitrobenzene compounds air sampling tube preparation and determination method / 中国职业医学

@#Objective - - To prepare the GDH 5 air sampling tube for simultaneous collection of eight kinds of chloro nitrobenzene （ ） ， compounds CNBs in the air of workplace and establish a matching determination method using gas chromatography. Methods - - ， Eight kinds of CNBs in vapor and aerosol state were collected by self developed GDH 5 air sampling tube desorbed ， ， ， by toluene separated by polysiloxane gas chromatography column detected by microcell electron capture detector and Results - （ - quantified by external standard method. It was determined that the air sampling tube was assembled by XAD 2 ion ） - ， exchange resin and glass fiber filter membrane. The linear range of CNBs was 0.80 240.00 mg/L and the linear correlation - - coefficients were greater than 0.999 9. The detection limit was 7.87 13.03 μg/L. The minimum detectable concentration was 0.60 3， - 3（ ） 1.33 μg/m and the minimum quantitative concentration was 2.00 4.22 μg/m sample 45.00 L . The average desorption - - （RSD） - ， - RSD efficiency was 101.2% 110.0%. The within run relative standard deviation was 0.8% 4.1% and the between run - Conclusion - was 0.3% 5.8%. The samples could be stored for more than 30 days at room temperature. GDH 5 air sampling tube and its associated determination method can be used for the collection and determination of eight kinds of CNBs in workplace air.

Method Development for Quantification of Donor-Acceptor Complexes of Alverine Citrate and Tapentadol by Visible Spectrophotometry.

In this present work two colorimetric methods were developed based on donor-acceptor complexes of alverine citrate (ALV) and tapentadol (TAP) with cobalt thiocyanate. These methods were developed on Perkin Elmer LAMBDA 25 UV–VIS spectrophotometer with 1cm quartz cells. The colored species formed are the coordination complexes of the drugs (electron donor) and the central metal atom of cobalt thiocyanate (electron acceptor) which is extractable into nitrobenzene from aqueous solution. The reaction conditions were optimized and validated to achieve maximum colour intensity. The colored complexes show maximum absorbance measured at 625 nm for both ALV and TAP. The absorbances were found to increase linearly with an increase in concentration which was corroborated by the calculated regression coefficients (0.9998-0.9999). Linearity was obeyed in the range of 100-600 μg/ml for both ALV and TAP, respectively. The molar absorptivity, sandell’s sensitivity, LOD, LOQ and other validation parameters have been evaluated extensively as per ICH guidelines and all the parameters were found within the acceptance criteria for both methods. The proposed methods were proven to be more accurate, simple, precise and rapid by statistical validation of recovery studies and could be suitable for regular analysis.

Late presentation of secondary cycling – nitrobenzene poisoning: A rare case report.

We presented here a case of acute nitrobenzene poisoning in which effective clinical evaluation and timely management in form of repeated intravenous methylene blue and blood transfusions played a vital role to save a life. It is very important to take care of patient who presented late after heavy exposure form the secondary cycling of nitrobenzene from body stores. Clinicians should be aware of this uncommon, but treatable and potential serious poisoning of nitrobenzene. Methemogobinemia can leads to high mortality but effective treatment with methylene blue is preferential.

Two Cases of Methemoglobinemia Induced by the Exposure to Nitrobenzene and Aniline

OBJECTIVE: To report two cases of methemoglobinemia induced by inhaled nitrobenzene and dermally absorbed aniline. METHODS: We have evaluated a 37-year-old male worker exposed to nitrobenzene by inhalation while conducting maintenance job of mononitrobenzene pump and a 25-year-old male worker exposed dermally to aniline while unloading. RESULTS: The first case is a 37-year-old male exposed to nitrobenzene. His blood methemoglobin concentration level was initially 19.8%, and chest X-ray was normal. After oxygen therapy, the blood methemoglobin concentration level decreased to 2.1%, and the symptoms were alleviated. The second case is a 25-year-old male exposed dermally to aniline. His chest X-ray was normal, but blood methemoglobin concentration level reached maximally 46.8%. He was treated with methylene blue due to relatively high blood methemoglobin level. Gradually after the treatment, his methemoglobin concentration level was normalized to 0.8% and simultaneously symptoms were resolved. CONCLUSIONS: After the thorough exposure investigations and medical evaluations, we have concluded that these cases were methemoglobinemia induced by occupational exposure to nitrobenzene and aniline. We suggest that businesses which handle methemoglobinemia-causing substances control the engineering process strictly, implement periodic screening, and establish emergency patient management system.

Fatal nitrobenzene poisoning: Some case reports and medicolegal aspects.

Nitrobenzene is a synthetic organic compound, pale yellow in colour, freely soluble in alcohol, with a pleasant odour like that of bitter almonds or shoe polish. It is widely used in chemical industry, and is present in commercial products such as shoe and metal polish, ink, paint remover and soap. Poisoning due to nitrobenzene is usually chronic in nature, mainly due to occupational exposure, except for a few acute cases of industrial accidents or suicides. We report three cases of fatal nitrobenzene poisoning through oral ingestion. All persons consumed alcohol prior to, or along with nitrobenzene. The alleged manner of poisoning was different in every case (one case each of homicide, suicide and accident). Clinical features, autopsy findings and medicolegal aspects of nitrobenzene poisoning are discussed.

Effect of Nitrobenzene on Reproduction System of Male Mice / 环境与健康杂志

Objective To study the effect of nitrobenzene(NB) on the activity of enzymes and the content of zinc in the testis tissue of mice. Methods 40 male mice were divided into 4 groups, 10 in each, 3 groups were treated with NB at the doses of 2, 20, 200 mg/kg by gavage, the control group was treated with vegetable oil in the same volume, once a day, for 21 consecutive days. The activity of G-6-PD, LDH and the content of Zn2+ in testis cells were determined. Results The index of epididymis and testis in the groups of 200 mg/kg were significantly lower compared with the control and 2 mg/kg group (P0.05). The activity of G-6-PD, LDH and the content of Zn2+ in all the treated groups were lower than those in the control group (P

Effects of Nitrobenzene on Immunity Function of Mice / 环境与健康杂志

Objective To study the effects of nitrobenzene on macrophage function and lymphocyte proliferation in mice. Methods ICR mice were divided into groups and treated with nitrobenzene by gavage,once a day,at doses of 2,20 and 200 mg/kg respectively,for 21 consecutive days.The mice were killed after 21 days of treatment and then the effects of nitrobenzene on the organs index,the maerophage function and the lymphocyte proliferation were determined.Results The maerophage function and the lymphocyte proliferation decreased as the increase of the dose of nitrobenzene.Conclusion The results of the present paper show that nitrobenzene may inhibit the immunity function of mice.

Determination of Trace Nitrobenzene in Water by Leach-Spectrophotometry / 环境与健康杂志

Objective To develop a rapid method for the determination of trace nitrobenzene in water. Methods In the acidic medium, the separation and enrichment of trace nitrobenzene in water by the technique of extraction-back extraction was done. With catalyst copper salt, nitrobenzene can be reduced into aniline and through the diazotization with hydrochloride naphthyl ethylenediamine, then form a stable purple complex which can be determined by spectrophotometry. Results The maximum absorption of the complex was at 540 nm and the molar absorptivity was ?540=2.6?104 L/(mol?cm). Beer’s law was obeyed in the range of 0.5～40 ?g/25 ml. The rates of recovery were 104.1%～109.1% and the lowest detectable concentration was 0.002 mg/L, RSDs

Study on Degradation of Nitrobenzene by Integrated Microbial-Fe~0 Treatment System / 微生物学通报

The degradation of nitrobenzene(NB) using a combination of Fe0 and anaerobic microorganism was studied. Nitrobenzene could be degraded effectively and the synergistic effect between Fe0 and anaerobic microorganism was apparent,and the nitrobenzene removal efficiency increased with the increasing of Fe0;the optimum pH was 5.0～6.0;as cometabolizing substrate,glucose could promote the degradation of nitrobenzene;In case of high concentration of Fe2+ and Fe3+,the anaerobic biodegradation activity of nitrobenzene were inhibited in a certain degree;0.5 mg/L Fe2+ and Fe3+ were the optimum to accelerate biodegradation rate of nitrobenzene; the degradation kinetics of nitrobenzene were followed by first-order reaction, reaction rate constant reduced along with the concentration of nitrobenzene increased.

Pathways for Nitrobenzene Biodegradation / 微生物学通报

Nitrobenzene is one of the toxic compounds. Much work had focused on biodegradation of it sofar. Two main pathways for nitrobenzene biodegradation, oxidative and partial reductive pathways, were reviewed in this article. The mechanism of these pathways including involved enzymes and genes was introduce in details. Comparative analysis of the pathways would provide basis for the development and application of biodegradation technology for nitrobenzene and other organic pollutants.

THE ISOLATION AND RESEARCH OF NITROBENZENE DEGRADATIVEPLASMID FROM PSEUDOMONAS XN-1 / 微生物学通报

Pseudomonas XN 1 has the ability of degradation for organic pollutant nitrobenzene, and the resistance to ampicillin In this paper, the plasmid was detected and isolated from the cell of Pseudomonas XN 1, and plasmid pXN 1 whose size is about 22 kb was gained The experiment of plasmid elimination confirmed that the plasmid has some relation to the ability of nitrobenzene degradation, while it is irrelevant to the resistance to ampicillin The feature difference between XN 1and its spontaneous mutants was corresponding to the difference of the plasmids detection, and a derivative plasmid pXN 13 was obtained from mutant XN 13 which is a few kb smaller than pXN 1