Identification and quantification of ethylene glycol and diethylene glycol in plasma using gas chromatography-mass spectrometry

Novel Technique for Simultaneous Ethylene Glycol and Its Metabolites Determination in Human Whole Blood and Urine Samples Using GC-QqQ-MS/MS

Toxicological analyses often necessitate the identification of compounds belonging to diverse functional groups. For GC-MS analyses, derivatization of compounds belonging to different functional groups can pose a challenge and requires the development of comprehensive methods of analysis. One example could be ethylene glycol, whose widespread use is related to possible unintentional or suicidal intoxications. This fact clearly indicates the need to develop sensitive methods for the determination of ethylene glycol and its metabolites in biological material, as only such complex analysis allows for proper toxicological expertise. A simultaneous GC-QqQ-MS/MS method for the determination of ethylene glycol together with its metabolites, glyoxal and glycolic acid, as well as the detection of glyoxylic acid and oxalic acid, was developed and fully validated. A novel approach for simultaneous derivatization of substances from different groups (alcohols, aldehydes, and carboxylic acids) was established. Sample preparation included the addition of three internal standards (BHB-d4, ethylene glycol-d4 and methylglyoxal), precipitation with acetonitrile and subsequent derivatization with N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA), as well as pentafluorophenylhydrazine (PFPH). Detection was carried out with the use of triple quadrupole mass spectrometer. The ionization method was electron impact, and quantitative analysis was carried out in multiple reaction monitoring mode. The lower limit of quantification was 1 μg/mL, 0.1 μg/mL, and 500 μg/mL for ethylene glycol, glyoxal, and glycolic acid, respectively. The presented method was applied in three authentic postmortem cases of ethylene glycol intoxication.

Enhanced Heat Transfer in Moderately Ionized Liquid Due to Hybrid MoS2/SiO2 Nanofluids Exposed by Nonlinear Radiation: Stability Analysis

This study considers ethylene-glycol as a moderate ionized regular liquid whose rheological behavior can be analyzed through the relations of the Carreau stress–strain tensor. Hybrid nanoliquids are potent liquids that give better performance for heat transfer and the properties of thermo physical than regular heat transfer liquids (water, ethylene glycol, and oil) and nanoliquids by single nanomaterials. Here, a type of hybrid nanoliquid involving silicon oxide (SiO2) and Molybdenum disulfide (MoS2) nanoparticles with ethylene glycol as a base liquid are considered. In addition, the impact of nonlinear radiation along with Lorentz force is invoked. Similarity variables are utilized to acquire the numerical findings and their solutions for transmuting ordinary differential equations (ODEs). Using bvp4c from MATLAB, we can obtain these quantitative and numerical results of the converted nonlinear equations. The impacts of the pertinent constraints on the temperature distribution, velocity, Nusselt number, and skin friction are estimated. The outcomes indicate that the double-edged methods for the results originate from the precise values of the permeable parameters. Further, the critical values (Sc = 1.9699, 2.0700 and 2.2370) are enhanced due to the influence of the local Weissenberg number. This implies that the increasing value of the local Weissenberg number accelerate the boundary layer separation. Furthermore, a stability investigation is performed and confirms that the first solution is a physically reliable solution.

Detection and quantitative determination of diethylene glycol in ethyl alcohol using gamma- ray spectroscopy

Determination of the toxic diethylene glycol contamination in ethyl alcohol demands a rapid, accurate and reliable method. Diethylene glycol (DEG) ingestion, accidental or intentional, can lead to death. Clinical and analytical methods used to detect diethylene glycol in alcohol require several hours to days due to tedious instrument handling and measurements. Enzymatic assays face difficulty due to analytic problems. As an alternative method of data analysis, we have used γ-ray spectroscopic method to estimate the diethylene glycol contamination in alcohol by monitoring the variation in the linear and mass attenuation coefficients. This method is simple, robust, portable and can provide reliable and quantitative information about the ethyl alcohol adulterated with diethylene glycol which is of broader interest to society.

Ethylene glycol poisoning: quintessential clinical toxicology; analytical conundrum

Ethylene glycol poisoning is a medical emergency that presents challenges both for clinicians and clinical laboratories. Untreated, it may cause morbidly or death, but effective therapy is available, if administered timely. However, the diagnosis of ethylene glycol poisoning is not always straightforward. Thus, measurement of serum ethylene glycol, and ideally glycolic acid, its major toxic metabolite in serum, is definitive. Yet measurement of these structurally rather simple compounds is but simple. This review encompasses an assessment of analytical methods for the analytes relevant for the diagnosis and prognosis of ethylene glycol poisoning and of the role of the ethylene glycol metabolites, glycolic and oxalic acids, in its toxicity.

Pre-existing liver cirrhosis reduced the toxic effect of diethylene glycol in a rat model due to the impaired hepatic alcohol dehydrogenase

Hepatic metabolizing enzymes of diethylene glycol (DEG) are impaired in liver diseases. Thus, the purpose of this study was to increase our understandings in metabolism and toxicology of DEG by clarifying the influences of pre-existing liver disease. Forty Sprague-Dawley rats with carbon tetrachloride-induced liver cirrhosis and 20 control rats were intraperitoneally administered a single dose of DEG, and randomly killed 1, 2, 5 or 8 days following exposure. Compared with control rats, the model rats had significantly higher blood CO(2)-combining power, lower blood urine nitrogen, serum creatinine and alanine aminotransferase levels on the second day and a lower mortality rate on the eighth day following DEG exposure. Enlargements of liver and kidneys and degeneration and necrosis of hepatocytes and renal tubules in the model rats was also less serious than in the control rats. Urine DEG levels were significantly higher on the first day in the model rats than the control rats (46.65 ± 8.79 mg vs 18.88 ± 6.18 mg, p < 0.01), but DEG concentrations in the blood, liver and kidneys were lower. Hepatic alcohol dehydrogenase (ADH) activity in the model rats was significantly lower than that in the control rats, which was positively related to renal damage. The toxic effects of DEG in rats with pre-existing liver cirrhosis are significantly reduced, which may be due to the decreased hepatic ADH activity. It suggests that the metabolite of ADH is responsible for DEG poisoning, and this toxic metabolite may mainly originate in the liver.

Simultaneous determination of diethylene glycol and propylene glycol in pharmaceutical products by HPLC after precolumn derivatization with p-toluenesulfonyl isocyanate

A simple and reliable HPLC method was developed for the simultaneous quantitative analysis of diethylene glycol (DEG) and propylene glycol (PG) in pharmaceutical products by precolumn derivatization. The derivatization reagent p-toluenesulfonyl isocyanate (TSIC, 10 microL, 20% in ACN v/v) was added to 100 microL of the sample, and then 10 muL of water was added. The resulting derivatives were separated using a C(18)analytical column and a mobile phase composed of 0.01 M KH(2)PO(4)buffer (adjusted to pH 2.5 with phosphoric acid) and ACN (47:53 v/v) at 1 mL/min and 25 degrees C. For detection, UV light at 227 nm was used. The derivatization conditions including reaction time, temperature, and concentration of TSIC were optimized. The calibration curves were linear from 0.062 to 18.6 microg/mL (r(2)= 0.9999) and from 0.071 to 21.3 microg/mL (r(2) = 0.9999) for DEG and PG, respectively. The RSD values of intra- and interday assays were all below 4% for DEG and PG. The proposed method was then successfully applied to analyze two Armillarisin A injection samples and two spiked syrup samples.

Validated gas chromatographic-mass spectrometric assay for determination of the antifreezes ethylene glycol and diethylene glycol in human plasma after microwave-assisted pivalylation

A gas chromatographic-mass spectrometric assay is described for identification and quantification of the antifreezes ethylene glycol (EG) and diethylene glycol (DEG) in plasma for early diagnosis of a glycol intoxication. After addition of 1,3-propanediol as internal standard, the plasma sample was deproteinized by acetone and an aliquot of the supernatant was evaporated followed by microwave-assisted pivalylation. After gas chromatographic separation, the glycols were first identified by comparison of the full mass spectra with reference spectra and then quantified. The quantification has been validated according to the criteria established by the Journal of Chromatography B. The assay was found to be selective. The calibration curves for EG and DEG were linear from 0.1 g/l to 1.0 g/l. The limit of detection for EG and DEG was 0.01 g/l and the limit of quantification for both was 0.1 g/l. The absolute recoveries were 50 and 65% for the low quality control samples and 51 and 73% for the high quality control samples of EG and DEG, respectively. Intra- and inter-day accuracy and precision were inside the required limits. The glycols in frozen plasma samples were stable for more than 6 months. The method was successfully applied to several authentic plasma samples from patients intoxicated with glycols. It has also been suitable for analysis of EG and DEG in urine.

Gas chromatographic determination of 3-butene-1,2-diol in urine samples after 1,3-butadiene exposure

1,3-Butadiene is an important industrial chemical and a common environmental contaminant. Because of its suspected carcinogenicity butadiene-related research has gained high activity. The obvious lack of knowledge so far has been that a biomonitoring method that can detect at least one of the metabolites of butadiene from body fluids or excretas does not exist. In this communication we describe a robust and simple analytical method which can be applied for biomonitoring purposes. We have developed a method that can detect 3-butene-1,2-diol in urine samples of rats inhalation-exposed to various concentrations of 1,3-butadiene. The method is based on liquid-liquid extraction and subsequent gas chromatographic analysis. The extraction efficiency of 3-butene-1,2-diol at a concentration of 2.2 microg/ml was 95% (SD=+/-3%, n=3) and was achieved by using sodium chloride saturation and isopropanol as an extracting solvent. The standard deviation of the gas chromatographic analysis was +/-2% (n=12), the limit of detection was 0.08 microg/ml, the limit of quantitation was 0.11 microg/ml (SD=+/-4.8%, n=3) and the analysis was observed to be linear from 0.11 to 486 microg/ml (R=0.9987). Animals exposed to 1,3-butadiene showed a linear excretion of 3-butene-1,2-diol into urine as a function of butadiene exposure. During the exposure saturation of metabolism or accumulation of 1,3-butadiene or 3-butene-1,2-diol into the body was not observed in any exposure levels used.

Gas chromatographic-mass spectrometric identification and quantitation of ethylene glycol in serum after derivatization with perfluorooctanoyl chloride: a novel derivative

Ethylene glycol poisoning is a common clinical problem and identification as well as quantitation of ethylene glycol in serum is important for medical and legal purposes. Most investigators described determination of ethylene glycol by gas chromatography without derivatization or derivatives forming a molecular ion < 200. We describe a novel derivatization technique of ethylene glycol using perfluorooctanoyl chloride, after extraction from serum using acetone. This derivative has a molecular mass of 854 and produces a base peak at m/z 441 and other diagnostic strong peaks for unambiguous identification. Moreover, this derivative is less volatile and is free from interferences from endogenous serum components. Quantitation can be achieved by using 1,4-butanediol as an internal standard. The assay showed within-run and between-run precision of 7.2% and 8.0%, respectively, and linearity over the serum ethylene glycol concentration range 70-2240 micrograms/ml with a detection limit of 5 micrograms/ml.

Simultaneous determination of ethylene glycol, propylene glycol, 1,3-butylene glycol and 2,3-butylene glycol in human serum and urine by wide-bore column gas chromatography

A method has been developed for the separation and measurement of ethylene glycol and three other glycols (propylene glycol, 1,3-butylene glycol and 2,3-butylene glycol) in biological samples by wide-bore column gas chromatography with a flame ionization detector. The method used 1,3-propylene glycol (1,3-propanediol) as an internal standard. The method was linear at least from 2 to 1000 micrograms/ml, with a detection limit of 1 microgram/ml. Analytical recoveries were 89-98% for the different concentrations. Precision studies showed coefficients of variation of 1.5-7.7% for the different concentrations. The assay was applied to the analysis of biological samples from two patients who had ingested ethylene glycol and/or other glycols in a suicide attempt.