This article provides the results of research on the uniformity of amino acid test strips used with fluorescent DFO method. Ready to use amino acid test strips made of the absorptive material containing four reactive fields of exponentially decreasing amino acid concentrations, designed for DFO, ninhydrin, 1,2-indanedione methods were used in the study. The test strips were treated with DFO solution in order to measure the fluorescence emission level of DFO-amino acid reaction product for respective reaction fields. Based on the obtained results, the repeatability of emitted fluorescence measurements was observed, thus confirming the usability of test strips in DFO method verification of newly prepared reagents as well as the use of this method in routine laboratory work. Based on the findings, it should be assumed that test strips are also effective and suitable for verification of correctness of preparation of working solutions for the remaining amino acid based fingerprint visualization methods such as: ninhydrin, 1,2-indanedione, and 1,2-indanedione with zinc chloride.

W artykule przedstawiono wyniki badań, których celem było określenie, w jakim stopniu ozon wykorzystywany do dezynfekcji pomieszczeń wpływa na możliwość ujawnienia metodą DFO śladów linii papilarnych na podłożach papierowych. Gwałtowny wzrost zachorowani na COVID-19 skierował uwagę na dezynfekcję pomieszczeń technikami, które zapewniają bezpieczeństwo ich użytkownikom. Istotne staje się także zapewnienie bezpieczeństwa osobom otrzymującym przesyłki, na których mogą się znajdować patogeny. Ich inaktywacja powinna być dokonana w taki sposób, aby można było przeprowadzić badania pozwalające na identyfikację nadawcy, co jest istotne z punktu widzenia kryminalistyki. Ozonowanie jest techniką dezynfekcji wykorzystywaną od wielu lat, szczególnie do uzdatniania wody, w przemyśle spożywczym. Eksperymenty wykonano w pomieszczeniach o kubaturze ok. 20 m3 przy użyciu generatora ozonu dostępnego na rynku. Uzyskiwane stężenie gazowego ozonu nie przekraczało 10 ppm. Przeprowadzone badania potwierdziły, że ślady linii papilarnych pozostawione na papierze kserograficznym umieszczonym w pomieszczeniu poddanym ozonowaniu w stężeniu nieprzekraczającym 10 ppm nie ulegają zniszczeniu i z powodzeniem mogą być ujawnione metodą DFO. The effect of ozone disinfection of rooms on the efficacy of revealing dactyloscopic traces on the surface of the paper using the DFO method during the SARS-CoV-2 pandemic The article presents the results of research aimed at determining the extent to which ozone used for disinfecting rooms affects the possibility of developing fingerprints on paper using the DFO method. A sudden increase in COVID-19 cases has placed the focus on disinfection techniques for user safety. It is also becoming important to ensure the safety of parcels addressed to various recipients by inactivating pathogens, while maintaining the possibility of examination that can identify the sender, which is important from the point of view of forensics. Ozonation is a disinfection technique that has been used for many years, in particular for water treatment or in the food industry. The experiments were carried out in rooms with a cubature of approx. 20 m3 using an ozone generator available on the market. The obtained ozone gas concentration did not exceed 10 ppm. The conducted research confirmed that the traces of fingerprints left on xerographic paper placed in a room subjected to ozonation in a concentration not exceeding 10 ppm are not damaged and can be successfully developed with the DFO method.

The study shows the results of fluorescence emission intensity measurements of the reaction products of selected amino acids with DFO, 1,2-IND and 1,2-IND - zinc chloride on absorptive surfaces. Conducted research addressed the following variables: type of developing reagent, type of surface, type of amino acid and sample storage time. It was confirmed that the above factors affected the fluorescence intensity of developed fingerprints. Furthermore, the studies proved that fluorescence intensity of reaction products between amino acids and 1,2- IND stored for 1 or 7 days increased for the majority of samples upon addition of zinc chloride to the developing reagent. For samples stored for 4 months the highest fluorescence emission intensity was observed for DFO. No significant differences were found in fluorescence spectral characteristics of tested compounds, depending on the type of surface.