Comparative analysis of condom lubricants on pre & post-coital vaginal swabs using AccuTOF-DART Gloria Proni a, *, Peter Cohen b , Lesley-Ann Huggins a , Nasri Nesnas b, ** a John Jay College of Criminal Justice, CUNY, Science Department, 524 West 59th Street, 5.66.12 NB, New York, NY 10019, United States b Florida Institute of Technology, Department of Chemistry, 150 W. University Blvd., 323 Olin Physical Sciences Building, Melbourne, FL 32901, United States A R T I C L E I N F O Article history: Received 16 May 2017 Received in revised form 26 August 2017 Accepted 4 September 2017 Available online xxx Keywords: Forensic science Nonoxynol Sexual assault Pre- and post-coitus samples Direct Analysis in Real Time Mass Spectrometry Time of flight A B S T R A C T In this study we demonstrate the use of Direct Analysis in Real Time Mass Spectrometry (DART) as a powerful tool for detection of nonoxynol in vaginal fluid post contact with a condom, enabling rapid tracing and added evidences in sexual assault crimes. Vaginal fluid was sampled using cotton swabs and glass rods and measured directly with DART. Sample preparation using water, hexane, methanol, and dichloromethane extraction, was explored for comparison and optimization of signals. Nonoxynol was detected up to eight hours after sampling. Optimal sampling conditions and mass spectrometry parameters are reported and discussed. © 2017 Elsevier B.V. All rights reserved. 1. Introduction In the past decade, there has been a significant increase in sexual assault cases in which the perpetrators use condoms. Since the advent of sophisticated DNA analysis, sexual offenders often use condoms to avoid leaving DNA samples at the crime scene. In sexual assault cases, lubricant trace evidence may supplement biological evidence, or may be the primary physical evidence when biological evidence is unavailable. Lubricants are used in condoms to preserve and extend shelf life.The lubricants often contain additives that aidin minimizing the chances of pregnancy through their spermicidal activity. Research done in the past, using various instrumentation, focused on studying the traces of additives and condom lubricants in condoms in order to be able to discriminate between condom brands [1]. While most of the methods and instrumentation employed were indeed sensitive, only occasionally were they discriminative [1]. Nonoxynol is the most common spermicidal ingredient. It may appear as a mixture of compounds that possess the constant nonylphenol moiety with varying lengths of para-oriented ethoxy chains that are all equally effective [2]. This mixture is a non-ionic surfactant, that is usually found in concentrations between 5% and 10% in spermicidal lubricant formulas. The spermicidal effect comes from disrupting the production of enzymes required for the sperm to enter the egg [3]. Nonoxynol is a good target compound for identification of the presence of lubricant due to its persistent nature as it lingers in the vaginal vault. While there could be several compounds present on condoms, it is more reliable to resort to the recognizable pattern of nonoxynol such that it appears amongst the mixture of other ion peaks. Since nonoxynol has varying lengths of the repeating ether unit CH 2 CH 2 O unit with a mass of 44, it distinctly stands out amongst other peaks. Furthermore, the presence of the multiple oxygen atoms renders for a facile ionization process, which out competes the ionization of other possible analytes present from the vaginal swab. This results in an enhancement in the detection limit. Nonoxynol is also stable enough and does not react with other compounds possibly present in vaginal fluids, thereby serving as an unambiguous marker for the use of condoms carrying that mixture of spermicide. Several types of analyses have already been reported for the forensic analysis of vaginal fluid including Electrospray Ionization and Matrix Assisted Laser Desorption Ionization [4] , High Pressure Liquid Chromatography [5] , Gas Chromatography Mass Spectrometry [6], and Capillary Electrophoresis [1a] . Many of these methods require extensive sample preparation or run time. The overall goal of this investigation was to find both a sensitive and discriminatory methodology to analyze condoms’ residues and volunteers’ vaginal swabs. * Corresponding author. Fax: +1 212 621 3739. ** Corresponding author. Fax: +1 321 674 8951. E-mail addresses: gproni@jjay.cuny.edu (G. Proni), nesnas@fit.edu (N. Nesnas). http://dx.doi.org/10.1016/j.forsciint.2017.09.005 0379-0738/© 2017 Elsevier B.V. All rights reserved. Forensic Science International 280 (2017) 87–94 Contents lists available at ScienceDirect Forensic Science International journal homepage: www.elsevier.com/locat e/f orsciint