IDENTIFICATION OF LUBRICATING OILS ON CLOTHING BY COLUMN CHROMATOGRAPHY, INFRARED SPECTROSCOPY, AND REFRACTOMETRY

• NCJ Number: 11683
• Journal: Journal of Forensic Sciences Volume: 18 Issue: 3 Dated: (JULY 1973) Pages: 263-270
• Author(s): H L YIP
• Date Published: 1973
• Length: 8 pages
• Corporate Author: American Soc for Testing and Materials
• Publication Format: Article
• Language: English
• Country: United States of America

Annotation

METHOD INVOLVING THE USE OF SOLVENT EXTRACTION, ALONE OR COMBINED WITH CHROMATOGRAPHY, AND THE DETERMINATION OF THE REFRACTIVE INDEX AND AROMATIC CONTENT OF THE OIL.

Abstract

FRESH OILS CAN BE IDENTIFIED FROM THEIR INFRARED SPECTRA AND REFRACTIVE INDICES. THE IDENTIFICATION IS MORE DEFINITE WHEN THE OIL IS FRACTIONATED AND THE PETROLEUM AND ADDITIVE FRACTIONS ARE INDIVIDUALLY COMPARED WITH CORRESPONDING FRACTIONS OF A CONTROL SAMPLE. USED OILS CAN BE IDENTIFIED AS DEFINITELY AS FRESH OILS IF THE OIL HAS NOT BEEN EXPOSED FOR EXTENDED PERIODS OF TIME TO OXIDIZING CONDITIONS. SUCH EXPOSURE RESULTS IN THE SIGNIFICANT LOSS OF AROMATICS AND DECOMPOSITION OF THE ADDITIVES. THE AUTHOR EXPLAINS HOW CERTAIN AREAS OF THE INFRARED SPECTRUM ARE LESS SUSCEPTIBLE TO INTERFERENCE FROM MATERIALS EXTRACTED FROM MOST CLOTHING AND, THEREFORE, ARE MORE USEFUL IN DETERMINING THE AROMATIC CONTENT OF OIL IN STAINS ON CLOTHING. (AUTHOR ABSTRACT MODIFIED)