Recommendations for hair testing in forensic cases

Society of Hair Testing

 

published in: Forensic Science International 145 (2004) 83-84

 

1 Introduction

On Tuesday, October 7th 2003, representatives from 15 countries gathered in Heraklion, Crete, to discuss some issues involved in the analysis of hair for drugs of abuse. All representatives were either currently engaged in the analysis of hair samples in their own laboratories, or were conducting hair analysis through a third party laboratory facility.

The countries represented were as follows (in alphabetical order): Canada, Chile, France, Germany, Greece, Italy, Luxembourg, Norway, Poland, Portugal, Spain, Sweden, Switzerland, United Kingdom, and the USA.

While the consensus was discussed, there was no final result. The Board of the Society met, and agreed upon the wording of the Consensus in Sevilla, Spain, on January 24th 2004. They included the sections upon which the assembly had agreed.

 

2 Areas for discussion

2.1 Sampling, shipping, storage

These areas were addressed in a previous consensus from the Society of Hair Testing [1].

 

2.2 Decontamination

When hair analysis is being used to identify drug use, the major limitation is external contamination, which if not removed, can confuse exposure with actual drug use. The issue of external contamination must be addressed through multiple methodologies and cannot be solved through the simple application of any single approach.

 

2.3 Hair disintegration and extraction

 

2.4 Screening test

 

2.5 Criteria for mass spectrometric analysis

 

2.6 Specific drug classes

Drugs and metabolites in hair should be analyzed using valid methods. Detection levels will be different between drug classes. Some examples for specific drugs are presented below.

 

2.6.1 Opiates

A morphine or 6-acetylmorphine level of 0.2 ng/mg must produce a positive result.

Recommended Limit of Quantification (LOQ): < 0.2 ng/mg for each Compound,

Heroin consumption must be differentiated from codeine or morphine use by the presence of 6-acetyl-morphine.

 

2.6.2 Cocaine

A cocaine level of 0.5 ng/mg must produce a positive result.

Recommended Limit of Quantification (LOQ): £ 0.5 ng/mg for cocaine; £ 0.05 ng/mg for other compounds.

The chromatographic analysis should include cocaine and at least one of the following: benzoylecgonine, cocaethylene, norcocaine or ecgonine methyl ester.

 

2.6.3 Amphetamines

A concentration of 0.2 ng/mg of each substance must separately produce a positive result: MDMA, methamphetamine, amphetamine, MDEA or MDA.

Recommended Limit of Quantification (LOQ): £ 0.2 ng/mg for each compound.

Note: Laboratories should be aware of the possible ingestion of legal drugs producing positive results for methamphetamine and amphetamine.

 

2.6.4 Cannabinoids

A THC concentration of 0.1 ng/mg must produce a positive result.

Recommended Limit of Quantification (LOQ): THC: £ 0.1 ng/mg, THC-COOH: £ 0.2 pg/mg

Confirmation of THC-COOH is required to definitively prove the use of cannabinoids

 

2.7 Internal quality control

Internal quality control for hair is more difficult than for other homogenous body fluids, since spiked control samples cannot Substitute for the actual hair of a drug user. However, spiked controls may be substituted for hair from drug users, if properly prepared.

 

2.8 External quality control

 

Reference

[1] Anon., Society of Hair Testing, Forensic Sci. Int. 84 (1997) 3-6.