Quantitative determination of valproic acid in postmortem blood samples—evidence of strong matrix dependency and instability

2013 ◽  
Vol 127 (6) ◽  
pp. 1101-1107 ◽  
Author(s):  
Verena Kiencke ◽  
Hilke Andresen-Streichert ◽  
Alexander Müller ◽  
Stefanie Iwersen-Bergmann
2005 ◽  
Vol 24 (4) ◽  
pp. 275-281 ◽  
Author(s):  
Vassiliki A. Boumba ◽  
Theodore Vougiouklakis

Numerous methods have been described in the literature for the determination of carboxyhemoglobin (COHb) in whole blood. The most popular and widely used have been (1) the spectrophotometric methods, which could be performed either by using a conventional spectrophotometer or by using specialized automated instruments known as CO-oximeters; (2) the gas chromatographic methods, with variable detection systems, which have been considered as the reference methods for every carbon monoxide analysis. The authors have critically reviewed previously reported comparative studies on these methods, considering statistical and analytical matters, in order to propose the best method for the determination of COHb in postmortem blood, that could be utilized in forensic toxicology laboratories where such analyses are limited in number (less than 20 per year). Criteria for evaluation have been accuracy, reliability, simplicity, time, and cost. The authors’ concluding statement has been that the manual spectrophotometric method could be the method of choice for COHb determination in postmortem blood samples. It is simple, rapid, and reliable and fulfills the forensically acceptable accuracy. It is performed by the use of a conventional spectrophotometer, which is considered a basic instrument in every analytical laboratory.


1990 ◽  
Vol 35 (6) ◽  
pp. 12967J ◽  
Author(s):  
Fumiyo Kusu ◽  
Taeko Tsuneta ◽  
Kiyoko Takamura

2014 ◽  
Vol 29 (4) ◽  
pp. 523-528 ◽  
Author(s):  
Arianna Silva-Trujillo ◽  
José Correa-Basurto ◽  
Aurelio Romero-Castro ◽  
Arnulfo Albores ◽  
Jessica Elena Mendieta-Wejebe

Author(s):  
Camila Scheid ◽  
Sarah Eller ◽  
Anderson Luiz Oenning ◽  
Eduardo Carasek ◽  
Josias Merib ◽  
...  

Abstract Synthetic drugs for recreational purposes are in constant evolution, and their consumption promotes a significant increase in intoxication cases, resulting in damaging public health. The development of analytical methodologies to confirm the consumption of illicit drugs in biological matrices is required for the control of these substances. This work exploited the development of an extraction method based on homogenous liquid–liquid microextraction with switchable hydrophilicity solvent (SHS) as extraction phase for the determination of the synthetic drugs 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine and N-methoxybenzyl-methoxyphenylethylamine derivates (25B, 25C and 25I) in postmortem blood, followed by liquid chromatography coupled to mass spectrometry in tandem. The optimized sample preparation conditions consisted of using 250 µL of ZnSO4 10% and 50 µL of NaOH 1 mol/L in the protein precipitation step; N,N-dimethylcyclohexylamine was used as SHS, 650 μL of a mixture of SHS:HCl 6 mol/L (1:1 v/v), 500 μL of whole blood, 500 μL of NaOH 10 mol/L and 1 min of extraction time. The proposed method was validated, providing determination coefficients higher than 0.99 for all analytes; limit of detection and limit of quantitation ranged from 0.1 to 10 ng/mL; intra-run precision from 2.16% to 9.19%; inter-run precision from 2.39% to 9.59%; bias from 93.57% to 115.71% and matrix effects from 28.94% to 51.54%. The developed method was successfully applied to four authentic postmortem blood samples from synthetic drugs users, and it was found to be reliable with good selectivity.


1984 ◽  
Vol 139 (1) ◽  
pp. 29-36 ◽  
Author(s):  
F. Degel ◽  
R. Heidrich ◽  
R.D. Schmid ◽  
G. Weidemann

2018 ◽  
Vol 71 (3) ◽  
pp. 142 ◽  
Author(s):  
Lagabaiyila Zha ◽  
Weicheng Duan ◽  
Di Wen ◽  
Yadong Guo ◽  
Jie Yan ◽  
...  

The quantitative determination of H2S in the blood can provide valid evidence for H2S poisoning through occupational exposure. However, known traditional methods for the detection of H2S in blood are time consuming, require complicated pretreatments, and have low sensitivity. In this paper, a new fluorescence sensing assay is proposed for the rapid detection of H2S poisoning in forensic cases based on bovine serum albumin (BSA)-stabilised zinc/copper (Zn/Cu) bi-metal nanoclusters (Zn/Cu@BSA NCs). The as-prepared Zn/Cu@BSA NCs probes have been characterised by UV-vis absorption and fluorescence spectroscopy. The fluorescence of Zn/Cu@BSA NCs can be quenched through specific interactions between HS−/S2− and the Zn2+/Cu2+ bi-metal ions. Under optimised conditions, the fluorescence sensing method was linear in the concentration range of 2.5 nM to 30 mM with 0.69 nM as the limit of detection. Moreover, the practical feasibility of this fluorescence sensing method has also been demonstrated by the analysis of mice blood samples containing different levels of sulfide and human blood samples from forensic cases of H2S poisoning. Compared with gas chromatography/mass spectrometry (GC/MS), this fluorescence sensing method is quite simple, straightforward, and can be accurate for the quantitative determination of H2S poisoning in a few minutes for forensic analysis. Overall, this is the first report of a bi-metal fluorescence sensing assay for detecting H2S poisoning directly in blood. This research may provide a new approach for forensic toxicologists to monitor poisoning by H2S using a fluorescence-sensing method.


2007 ◽  
Vol 122 (2) ◽  
pp. 109-114 ◽  
Author(s):  
L. Frommherz ◽  
H. Köhler ◽  
B. Brinkmann ◽  
M. Lehr ◽  
J. Beike

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