New developments in hair research

Detection and quantification of etomidate and metomidate in human hairs by ultraperformance liquid chromatography with triple quadrupole mass spectrometry (UPLC-MS/MS)

PURPOSE

Intravenous narcotic agents, such as etomidate and metomidate, has been widely spread and abused in the world, including in Korea and China; thus, it is important to establish validated and sensitive analytical method for these compounds. Human hair as a biological sample has various advantages, including a wide detection window of drugs, compared to other typical samples, such as urine and blood in investigation. The purpose of this communication is to develop a reliable and useful method for the simultaneous detection and quantification of etomidate and metomidate in human hair samples by ultraperformance liquid chromatography combined with triple quadrupole mass spectrometry (UPLC-MS/MS), and to apply it for authentic samples in abuse cases.

METHODS

The hair samples were washed with a detergent solution, followed by with water and acetone. After drying, they were cut into approximately 2 mm sections and then ground to powder by a low-temperature grinder. The 20 mg of hair powder plus internal standard in 1 mL of methanol was vortexed and then centrifuged to obtain the supernatant layer, followed by subjecting to analysis.

RESULTS

The coefficient of determination (r2) values of the calibration curves of etomidate and metomidate in the hair samples were both more than 0.99 in the range of 1-500 ng/mg and 1-500 pg/mg, respectively. The limits of detection and lower limits of quantification were 0.5 and 1 pg/mg, respectively, for the both target compounds. Other tested validation data were all satisfactory. Etomidate and metomidate could be detected in the all hair samples and cigarette oil, which were seized by the police. The concentrations of etomidate and metomidate obtained from 10 samples from suspects were 5.48-45.7 ng/mg and 3.60-377 pg/mg, respectively. The concentrations of etomidate and metomidate in the cigarette oil were 95.8 μg/mg and 2.8 μg/mg, respectively.

CONCLUSIONS

In this study, a simple and reliable analytical method for etomidate and metomidate in the human hair has been established. To the best of our knowledge, this is the first report to establish a method for the simultaneous detection and quantification of etomidate and metomidate in the human hair, and to apply it to authentic samples seized in authentic cases.

Detection and quantification of psychotropic drug etaqualone in human hair using GC-MS/MS

In this study, sensitive analytical procedure for detection and quantification of etaqualone in human hair samples using gas chromatography tandem mass spectrometry (GC-MS/MS) was newly established, and applied it to authentic human samples obtained from an abuser. In this method, the hair samples were treated with hydrochloric acid and then extracted with ethyl ether. The ether layer was dried in a warm water bath, and the residue was reconstituted in ethyl acetate, followed by GC-MS/MS analysis. Multiple reaction monitoring (MRM) mode was used for data collection, and quantitative analysis was performed using internal standard method. Good linear relationship within the concentration range of 1-100 pg/mg were obtained in calibrators for the hair samples showing its correlation coefficient value was 0.9993. The lower limit of quantitation in this study was 1 pg/mg and the recovery rate examined ranged from 100.4% to 108.5%. The intra-day precision and accuracy were less than 5.0% and 5.8%, respectively. The inter-day precision and accuracy were lower than 6.4% and 4.6%, respectively. Using this established method, etaqualone could be detected in the hair sample obtained from a suspected user to be level of 65.2 pg/mg. It should be expected that the method established in this study would contribute to rapid detection and identification of psychotropic drug etaqualone among multiple fields including forensic investigation, clinical application and of course public health matters.

Following historical "tracks" of hair follicle miniaturisation in patterned hair loss: Are elastin bodies the forgotten aetiology?

Pattern hair loss (PHL) is a chronic regressive condition of the scalp, where follicular miniaturisation and decreased scalp hair coverage occurs in affected areas. In all PHL cases, there is a measurable progressive shortening of the terminal hair growth duration, along with reduced linear growth rates. In both genders, PHL initially shows an increase in short telogen hairs ≤30 mm in length, reflecting a cycle completion of under 6 months in affected terminal hair follicles. To understand the miniaturisation process, we re-examine the dynamics of miniaturisation and ask the question, "why do miniaturised hair follicles resist treatment?" In the light of recent developments in relation to hair regeneration, we looked back in the older literature for helpful clues "lost to time" and reprise a 1978 Hermann Pinkus observation of an array of elastin deposits beneath the dermal papilla following subsequent anagen/telogen transitions in male balding, originally described by Arao and Perkins who concluded that these changes provide a "morphologic marker of the entire biologic process in the balding scalp." Thus, we have reviewed the role of the elastin-like bodies in hair pathology and we propose that alterations in elastin architecture may contribute to the failure of vellus-like hair reverting back to their terminal status and may indicate a new area for therapeutic intervention.