Hair analysis analytical procedures

Since 1960, it has been demonstrated by various analytical procedures that high concentrations of arsenic were present in Napoleon s hair.88 Multi-element analysis of two specimens of Napoleon s hair by ICP-MS after mineralization in concentrated nitric acid resulted in arsenic concentrations (42.1 and 37.4(xgg-1) about 40 times higher than normal values, confirming the hypothesis of a significant exposure to arsenic. However, mercury (3.3. and 4.7(xgg 1), antimony (2.1 and 1.8(xgg 1) and lead (229 and 112p,gg-1) were also detected at elevated levels. The elevated concentrations of Sb and Hg are in agreement with the data already known about the therapeutic treatments given to Napoleon (calomel and tartar emetic are compounds of mercury and antimony, respectively).88... 

An analytical method for determining illicit drugs in the hair should include before analysis a proper washing procedure to eliminate possible external contamination, or traces of drugs that can be deposited on the outside of the hair, thus limiting the possibility of interference and false positives. The washes also remove residues of shampoo and cosmetics as well as sweat and sebum, which can cause problems of interference in the subsequent analytical procedures and increase the background noise recorded in instrumental analysis of the sample [42,132],... 

Due to the low amount of specimen used for hair analysis and the low concentration of drugs and their metabolites in hair, extraction procedures are mostly necessary to concentrate the analytes in the tested solution. Various methods have been used for this step. The variety of described procedures show that there is no universal solution. The choice of an extraction procedure may be influenced by the kind of drug and drug metabolite(s) to be analyzed and the method used for the subsequent analysis. Preceding the real extraction, there are four treatments with more or less intermethodical differences to prepare the hair matrix for the extraction ... 

Hair analysis by chromatographic procedures was reviewed in 1992 by Moeller. Analytical methods for the detection of drugs in hair were reviewed for amphet-amines, °7 cannabinoids, cocaine, ° and opiates. "... 

Initial studies performed during the late 1970s and early 1980s revealed the presence of benzoylecgonine (cocaine metabolite) and morphine (heroin metabolite) in hair. Since then, fiu-ther studies of hair analysis have identified additional cocaine analytes and opioids. The aim of this chapter is to provide a review of the analytical techniques utilized in hair analysis, including preliminary wash/decontamination procedures, methods of analyte isolation and pmification, and analysis of the hair extracts. In addition, this chapter will present research findings. 

Kauert, G. F., Drug analysis in hair samples applications and experiences with a new rapid analytical procedure, Z. Rechtsmed., 40, 229, 1993. 

We will show that the probative advantages of hair testing depend critically on the methods used for analysis wash procedures, kinetic analysis of the wash data, the digestion of the hair for the complete release of anal)des, the measurement of metabolites, and adoption of appropriate cutoff levels. These analytical procedures will be described in the present paper along with certain unique chemical and physical properties of hair which contribute greatly to the reliability of the analytical result. The advantages of a recently published proprietary method will also be discussed. 

The actual presence of large amounts of cysteic acid in bleached hair had at one time been in doubt [55, 56]. It had been theorized that the cysteic acid found in bleached hair hydrolysates was formed by decomposition of intermediate oxidation products of cystine during hydrolysis prior to the analytical procedure [55]. However, differential infrared spectroscopy [4] and electron spectroscopy for chemical analysis by Robbins and Bahl [5] on intact unhydrolyzed hair have conclusively demonstrated the existence of relatively large quantities of cysteic acid residues in chemically bleached hair. Evidence for other sulfur acids (e.g., sulfinic or sulfenic acids) in bleached hair has not been provided. It is unlikely that these amino acids exist in high concentrations in hair because these species are relatively unstable. 

Analytical procedures involving reduction and determination of mercaptan are not accurate determinations of cystine in permanent-waved hair or in hair treated with mercaptan because mixed disulfide is reduced to mercaptan during analysis adsorbed mercaptan can also interfere in the determination. Procedures that do not involve reduction of hair such as ninhydrin detection (alpha-amino group) or dinitrofluorobenzene (DNFB) reaction followed by chromatographic separation [1, 58] discriminate between mercaptans and, therefore, should be better analytical procedures for detecting the different types of mercaptans and disulfides actually present in permanent-waved hair. 

In summary, while hair analysis has been used to detect certain types of heavy metal poisoning (e.g., lead, arsenic, mercury) in populations, its value on an individual basis remains to be established. There are a number of limitations to hair analysis both in terms of analytical procedures and in interpretation of results. For example, the relationship between hair concentration of a trace element or of a vitamin and the concentration of other body tissues is unknown. Basically, hair analysis is of limited value for assessing mineral status and questionable for assessing vitamin status. 

Several variables must be considered in the analysis of hair besides the decontamination procedure. The most important is the method by which drugs are to be extracted from the hair matrix. Because no extraction solution can remove all of the drug present, dissolution of the hair matrix before extraction of the drug appears essential to achieve complete removal for analytical purposes. 

In the original heroin assay by Goldberger et al., heroin, 6-AM, morphine, and codeine were extracted by LLE and assayed simultaneously by GC/MS. The performance of the assay including analyte recovery and stability was not optimized, and the assay was limited by interference. Selective ion chromatograms of hair and standard extracts are illustrated in Figure 4. In an improved procedure by Goldberger et al., two sets of SPE extracts were assayed independently by GC/MS one set for heroin, and other set for the trifluoroacetyl derivatives of 6-AM and morphine. The extraction process, in combination with the use of aprotic solvents, mild elution solvents, and an enzyme inhibitor, provided maximum analyte stability for the recovery of heroin from hair with minimal (<5%) hydrolysis. The procedure was modified further by Cone et al. for the analysis of cocaine, heroin, and metabolites in hair. 

The method was developed according to a procedure analogous to the one described in Section 7.3.4. Sample preparation consisted of acidic hydrolysis of collected hair, followed by an extraction in solid phase extraction. The analysis of cocaine and its metabolites was carried out in GC-MS with an ion trap in a protocol that associated positive chemical ionization and MS/MS detection for each of the four analytes. No chemical derivation was carried out prior to analysis. 

---