Chinese Journal of Applied Chemistry ›› 2015, Vol. 32 ›› Issue (9): 1093-1098.DOI: 10.11944/j.issn.1000-0518.2015.09.150033

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Chromogenic Detection of Imprints Left by Zinc Coatings on Human Skins by 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol

XING Zhuo,YANG Ruiqin()   

  1. School of Forensic Science,People's Public Security University of China,Beijing 100038,China
  • Received:2015-01-27 Accepted:2015-05-07 Published:2015-08-31 Online:2015-08-31
  • Contact: YANG Ruiqin
  • Supported by:
    Supported by the Fundamental Research Funds for the Central Universities(No.2015JFK01230)

Abstract:

The detection of imprint left by zinc coatings on human skins was studied. The affecting factors such as contact time, time elapse from the contact to the reaction, concentration of 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol(5-Br-PADAP) reagent and washing on the intensity and resolution of imprints were studied and the reliability of this method was verified. As shown in experimental results, good imprints can be obtained with a concentration of 1 g/L of 5-Br-PADAP, contact time of 10 s, time elapse of less than 4 h. This method can develop imprints left by zinc coatings sensitively as a good supplement for the detection of imprints left by nonferrous metal tools.

Key words: forensic science, (bromo-pyridylazo)-(diethylamino)phenol, imprints left by zinc coatings, chromogenic detection