Forensic sciences sample preparation

LC-GC, therefore, shows promise for forensic science applications, reducing sample handling and preparation steps by essentially using an on-line LC column in place of one or more extraction steps. This is followed by a traditional high resolution GC analysis. The methods described here for pesticides and hormones could be readily adapted to a variety of analyses, especially those involving fatty matrices. Such as tissues, food or blood. 

The fact that Raman measurements can usually be made through glass and plastic packaging, eliminating the need to prepare samples prior to analysis, makes Raman spectroscopy very attractive for forensic science. The availability of commercial portable instramentation and extended fiber optic probes makes Raman suitable for on-site forensic use, minimizing the risk of exposure of investigating personnel to potentially hazardous chemicals. Eor identification of explosives the SERS method has proved to be very useful. A tiny amount of explosive, diluted... 

Chapter 3 dealt with sample preparation in more detail. In forensic science, we need to consider the likelihood of interference due to the sample matrix. 

Ren, Q. Bertsch, W. (1999) A comprehensive sample preparation scheme for accelerants in suspect arson cases. Journal of forensic science. 44, 3,504-515... 

Solvent Extraction Principles. Forensic Sciences Drug Screening in Sport Systematic Drug Identification. Gas Chromatography Mass Spectrometry Chiral Separations. Immunoassays, Techniques Enzyme Immunoassays Luminescence Immunoassays. Liquid Chromatography Column Technology. Pharmaceutical Analysis Sample Preparation. 

See also Air Analysis Sampling. Chromatography Overview Principles. Clinical Analysis Sample Handling. Drug Metabolism Metabolite Isolation and Identification. Extraction Solid-Phase Extraction. Food and Nutritional Analysis Sample Preparation. Forensic Sciences Volatile Substances. Headspace Analysis Purge and Trap. Perfumes. Sample Handling Sample Preservation Automated Sample Preparation. Sampling Theory. 

Bertsch W and Ren Q (1999) Contemporary sample preparation methods for the detection of ignitable liquids in suspect arson cases. Forensic Science Review 11 141-156. 

See alsa Chromatography Multidimensional Techniques. Environmental Analysis. Extraction Solid-Phase Extraction. Food and Nutritional Analysis Sample Preparation Contaminants Pesticide Residues. Forensic Sciences Drug Screening in Sport Illicit Drugs. Herbicides. Liquid Chromatography Instrumentation Clinical Applications Food Applications. Mass Spectrometry Peptides and Proteins. Pesticides. Pharmaceutical Analysis Sample Preparation. Proteomics. Sample Handling Automated Sample Preparation. Water Analysis Organic Compounds. 

Sample Handling. Forensic Sciences Blood Analysis Explosives Systematic Drug Identification. Nuclear Magnetic Resonance Spectroscopy Techniques Nuclear Overhauser Effect. Pharmaceutical Analysis Drug Purity Determination Sample Preparation. 

MS compatible with sample preparation techniques used in these fields. For MALDI, the minimum amount of protein needed for a spectrum of high quality was reduced from 1 pmol in 1988 to a few femtomoles only about a year later. Today, in favorable cases, the level is now down in the low attomole range. Many other developments - both instrumental (see Chapter 2) as well as specific sample preparation recipes and assays (see other chapters of the book) - took place during the following decade, and the joint impact of aU of these together has today made MALDI-MS an indispensable tool not only in the Hfe sciences but also in polymer analysis, food sciences, pharmaceutical drug discovery, or forensic jurisprudence. 

Figure 23-23 Microfluidic device for automated forensic ONA analysis being developed by the University of Arizona and the British Forensic Science Service. Features labeled V and 0 in the diagram of the sample preparation cartridge are valves. Other items are mentioned in the text. [Courtesy F. Zenhausern, University of Arizona. From A. Hopwood, C. Hurth, I. Yang, Z. Cai. N. Moran,...

While the dual inlet technique is generally the most precise method for stable isotope ratio measurements, the continuous-flow technique offers online sample preparation, smaller sample size requirements, faster and simpler analyses, increased cost-effectiveness, and the possibility of interfacing with other preparation techniques, including elemental analysis, gas chromatography (GC), and liquid chromatography (LC). For these reasons, CF-IRMS is the subject of the majority of research currently being conducted in the field of forensic science [1],... 

In order to develop this deployable technology, members of the Forensic Science Center at LLNL were tasked to research and develop new methodology and field portable equipment which includes the collection, preparation, and analysis of suspect samples. The analysis of CW compounds and their precursors at trace levels is a labor intensive, time consuming process, usually requiring a fully equipped laboratory. However, with the utilization of solid phase extraction (SPE) technology, sample preparation time is greatly reduced and cumbersome laboratory equipment is eliminated. 

This chapter concludes the first section of the text and has set the stage for our first forays into chemistry as applied to the world of forensic science. As with any analytical task, the first step is to understand and prepare samples, and this is the subject of the next chapter. 

Koester, C. J., et al. "Criminalistics— Technical Notes— Optimum Methamphetamine Profiling with Sample Preparation by Solid-phase Microextraction." Journal cf Forensic Sciences, 47 2002,1002-1006. 

A Comprehensive Sample Preparation Scheme for Accelerants in Suspect Arson Cases," Journal of Forensic Sciences 44 (1999), 504-515. Copyright 1999, ASTM International. 

---