Publications

Authors:

Musile, G; Gottardo, R; Palacio, C; Shestakova, Kseniia; Raniero, D; DE PALO, Elio Franco; Tagliaro, F.

Title:

Development of a low cost gas diffusion device for ammonia detection in the vitreous humor and its preliminary application for estimation of the time since death.

Year:

2019

Type of item:

Articolo in Rivista

Tipologia ANVUR:

Articolo su rivista

Language:

Inglese

Format:

A Stampa

Referee:

Sì

Name of journal:

Forensic science international

ISSN of journal:

0379-0738

N° Volume:

295

Page numbers:

150-156

Keyword:

ammonia; gas diffusion analysis; low cost analytical devices; post mortem interval; vitreous humour

Short description of contents:

A simple and low cost analytical device is described for the determination of ammonium in the vitreous humor suitable for inferring the post mortem interval in forensic cases. The device is based on ammonia formation from ammonium ion by means of NaOH addition to the vitreous humor sample and its detection with a pH chemical indicator in the gas phase above the vitreous humor sample. From the gas phase, ammonia diffuses through a polymeric membrane and it is trapped and detected with a droplet of pH indicator thymol blue. The color change of the droplet is measured using a smartphone camera. Under optimal conditions, the device showed a limit of detection of 0.2mM, with between days precision of ≤ 15% expressed as relative standard deviation, and an accuracy between days from 88.3% to 114.5%. This homemade gas diffusion analytical device was successfully used for the determination of ammonia in vitreous humor samples from forensic autopsies. The results obtained with the proposed method, although for a limited number, showed a close correlation with the data obtained with an instrumental analysis based on capillary electrophoresis. Moreover a significant correlation was also found between the results of the present method and the time elapsed since death by a simple evaluation of the color intensity. In conclusion, this preliminary study showed that the proposed device, after adequate validation, could be a promising tool for a presumptive estimation of the time since death directly at the crime scene.

Product ID:

108106

Handle IRIS:

11562/994019

Last Modified:

November 14, 2022

Bibliographic citation:

Musile, G; Gottardo, R; Palacio, C; Shestakova, Kseniia; Raniero, D; DE PALO, Elio Franco; Tagliaro, F., Development of a low cost gas diffusion device for ammonia detection in the vitreous humor and its preliminary application for estimation of the time since death. «Forensic science international» , vol. 295 , 2019 , pp. 150-156

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