Development of Rapid and Economical Colorimetric Screening Method for p-Phenylenediamine in Variety of Biological Matrices and its Application to Eleven Fatal Cases of p-Phenylenediamine Poisoning.

A rapid colorimetric method for detection of p-phenylenediamine (PPD) in various biological samples is developed. The o-cresol test for acetaminophen detection has been modified to detect PPD in blood, urine, gastric contents, and liver. After precipitating protein with trichloroacetic acid solution (2 mL, 10% w/v), biological specimens were required to convert PPD metabolites to PPD by acid hydrolysis. Finally, o-cresol solution (1 mL, 1% w/v), hydrogen peroxide (200 µL, 3%v/v), and concentrated ammonium hydroxide (0.5 mL) were added in the biological samples. The presence of PPD was indicated by formation of violet color which was turned to bluish green color within 10-15 min. The limit of detection was found to be 2 mg/L in blood, urine, and gastric contents and 2 mg/Kg in liver. This method is also free from any potential interference by p-aminophenol, acetaminophen, and other amine drugs under test conditions. This method was successfully employed to thirteen fatal cases of PPD poisoning.

Fatal Intoxications Due to Administration of Isosorbide Tablets Contaminated with Pyrimethamine.

In January 2012, 664 cases of pyrimethamine toxicity and 151 deaths were reported among cardiac patients that had recently received free medicines from pharmacy of Punjab Institute of Cardiology, Lahore, Pakistan. These patients, ages ranged from 58 to 75 years, were prescribed simvastatin, clopidogrel, aspirin soluble, isosorbide mononitrate, and amlodipine. On examination of medications being given to them, it was found that a particular batch of isosorbide mononitrate tablets was contaminated with 50 mg pyrimethamine. Cardiac patients were taking isosorbide contaminated with pyrimethamine twice daily (100 mg pyrimethamine/day), whereas therapeutic dose of pyrimethamine for malaria is 25 mg/week. Postmortem urine, cardiac blood, and femoral blood specimens of three deceased males were submitted to author's laboratory for analysis. Postmortem toxicological analysis revealed that pyrimethamine concentration fell within the range of 1-10 µg/mL by liquid chromatography. Clinical, autopsy, histopathological, and toxicological findings strongly suggested toxicity due to pyrimethamine accumulation that resulted in deaths of these cardiac patients.

Hair analysis of an unusual case of Chloroquine intoxication.

A dead body of middle aged man was exhumed from 6.5 month earth-grave. Autopsy findings were non-specific as the body was completely putrefied. Deceased's scalp hair and kidney was sent for toxicological analysis. Hair sample (50mg) was incubated with 1M NaOH (2 ml). Chloroquine was detected in hair and kidney during basic drug screen performed on GC/MS. For confirmation and quantitation, chloroquine was extracted using Hypersep verify CX SPE cartridges while mass detector was operated in SIM mode using the ions of m/z 245.0, 290.1, 319.0 for chloroquine while ions of m/z 260 and 455 were monitored for nalorphine (internal standard). Chloroquine was present in high concentration in hair (211 ng/mg) as well as in kidney (37.3mg/kg). Moreover, chloroquine was not detected in the wash solvents, suggesting ingestion of the drug rather than an external contamination of hair. These findings strongly suggested the acute exposure of higher doses of chloroquine to the deceased before death.

Analytical methods for determination of anticoagulant rodenticides in biological samples.

Anticoagulant rodenticides belong to a heterogeneous group of compounds which are used to kill rodents. They bind to enzyme complexes responsible for recycling of vitamin K, thus producing impairment in coagulation process. Rodenticides are among the most common house hold toxicants and exhibit wide variety of toxicities in non-target species especially in human, dogs and cats. This article reviews published analytical methods reported in literature for qualitative and quantitative determination of anticoagulant rodenticides in biological specimens. These techniques include high performance liquid chromatography coupled with ultraviolet and florescence detectors, liquid chromatography electrospray ionization tandem mass spectrometry, liquid chromatography with high resolution tandem mass spectrometry, ultra performance liquid chromatography mass spectrometry, gas chromatography mass spectrometry, ion chromatography with fluorescence detection, ion chromatography electrospray ionization ion trap mass spectrometry and ion chromatography electrospray ionization tandem mass spectrometry.