GA/T 2075.2-2023Forensic sciences - Examination methods for common ignitable liquid and its residues - Part 2: Purge and trap-GC/MS (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents" Drafting.

This document is Part 2 of GA/T 2075 "Examination of Common Flammable Liquids and Their Residues in Forensic Science". GA/T 2075 has been the following sections were published.

---Part 1: Solvent extraction - gas chromatography/mass spectrometry;

---Part 2: Purge and Trap-Gas Chromatography/Mass Spectrometry;

---Part 3: Thermal Desorption-Gas Chromatography/Mass Spectrometry.

Please note that some content in this document may be subject to patents. The publisher of this document assumes no responsibility for identifying patents.

Introduction

Fire-related cases seriously endanger people's lives and social stability. In the field of forensic science and fire investigation, the analysis of fire residues Analysis is an important part. The establishment of systematic and standardized technical standards is conducive to improving the field of forensic science involving flammable liquids and their residues in fire cases.

Maintain the standardization, relevance and mutual recognition of results of physical and chemical inspections.

GA/T 2075 "Inspection of Common Flammable Liquids and Residues in Forensic Science" technical system plan is divided into five parts, and with the development of technology it will be gradually improved and released one after another.

---Part 1: Solvent Extraction - Gas Chromatography/Mass Spectrometry. This document applies to gasoline, kerosene, diesel and other chemicals used in forensic science.

Inspection of other flammable liquids and their residues.

---Part 2: Purge and Trap-Gas Chromatography/Mass Spectrometry. This document applies to gasoline, kerosene, and other common Inspection of flammable liquids (such as paint thinner) and their residues.

---Part 3: Thermal Desorption-Gas Chromatography/Mass Spectrometry. This document applies to gasoline, kerosene, diesel and other Inspection of common flammable liquids (such as paint thinner) and their residues.

---Part 4: Forensic Science Gasoline Residue Extraction Testing Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry. This standard has been Released and implemented in 2018, the standard number is GA/T 1515-2018, which is suitable for the inspection of gasoline in the field of forensic science. along with with the continuous development of technology and applications, it is planned to revise this standard and classify it into "Common flammable liquids and their residues in forensic science".

Part 4 of the Technical Specifications for Physical Inspection.

---Part 5: Technical Guidelines for Inspection of Flammable Liquids and Their Residues. This document applies to flammable liquids commonly found in forensic science and technical process specification guidance for physical and chemical testing of residues.

These five parts complement each other to form a complete technical system, which provides a basis for the analysis of flammable liquids and their residues in forensic science fire-related cases.

Chemical inspection provides normative guidance.

Forensic science testing of common flammable liquids and their residues Part 2: Purge and Trap-Gas Chromatography/Mass Spectrometry

1 Scope

This document specifies a purge-and-trap gas chromatography/mass spectrometry test method for gasoline, kerosene, and their residues in the field of forensic science.

This document is applicable to the detection of gasoline, kerosene and other common flammable liquids (such as paint thinner) and their residues in the field of forensic science.

It can be used as a reference in other fields.

2 Normative reference documents

The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, the dated quotations for undated referenced documents, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document.

GB/T 14666 Analytical Chemistry Terminology GB/T 19267.7 Physical and chemical examination of criminal technical trace evidence Part 7: Gas chromatography-mass spectrometry GB 30000.7 Specifications for Classification and Labeling of Chemicals Part 7: Flammable Liquids GA/T 242 Terminology for physical and chemical examination of trace evidence in forensic science

3 Terms and definitions

The terms and definitions defined in GB/T 14666, GB/T 19267.7, GB 30000.7 and GA/T 242 apply to this document.

4 Principles

After the flammable liquid burns, some components remain in the fire residue. Gasoline and other light easy substances enriched in the adsorber are passed through inert gas.

The fuel liquid and its residual components are blown out and adsorbed on the trap. The trap is heated and desorbed, and the volatile components are backflushed into the gas chromatograph-mass spectrometer.

Perform testing.

5 Reagents and materials

Reagents and materials include.

a) Adsorption tube (filled with Tenax or other adsorbents with similar adsorption efficiency);

b) Nylon film bag or nylon film bag with adsorption tube connection port;

c) Qualitative filter paper;

d) Microsyringe (10µL);

e) Comparison sample. gasoline, kerosene or other flammable liquids;

f) High purity helium;

g) High purity nitrogen.