Izvorni znanstveni članak
The quenching effect of urine on the chemiluminescence of luminol
Karlo Weber
; Institut za higijenu rada Zagreb
Jelena Frketić
; Intitut za sudsku medicini i kriminalistiku Medicinskog fakulteta Zagreb
Sažetak
The chemiluminescence of luminol (3-aminophtalhydrazine), which appears in alcaline solutions in presence of hydrogen peroxide and suitable catalysers (haemoglobin, haemine, etc.) is strongly inhibited by human and animal urine. The quenching or luminescence may be regarded as a consequence of the inhibiting action of urine on the chemical reaction which induces the chemiluminescence of luminol. The quenching effect of urine was studied by measuring the intensity of chemiluminescence as a function of various factors. The following facts were established. A noticeable quenching effect may be observed al concentrations of urine amounting to not more than o. 2 vol. %. lt is almost complete (96%) at concentrations of 1-2 vol. %. There is an insignificant difference in the quenching power of urine obtained from different healthy individuals. The drying and subsequent disolution of urine has no marked influence on its quenching power. In order to identify the active substances in urine experiments were performed with several urine constituents such as: urea, uric acid, glucose, acetone, phenol. Lactic, phosphoric, formic, citric, oxalic and ascorbic acids, pepsin and xanthopterin. The listed substances were added to the reaction mixture in concentrations normally occuring in urine. Under such conditions uric acid is the only constituent having a strong quenching effect on the luminescence. Its quenching power is, however, less than the quenching power of urine. Thus it may be supposed that there are other factors in urine which influence the inhibition of chemiluminescence of luminol, for instance the yellow urine dyestuffs, which may act as internal optical filters. In larger concentrations quenching affects have also been noticed with phenol and ascorbic acid. It is believed that these phenomena could be used as basis for the development of a quick and practical physical-chemical method for detecting urine in various materials in forensic analyses.
Ključne riječi
Hrčak ID:
187236
URI
Datum izdavanja:
6.3.1953.
Posjeta: 939 *