Evaluation of Pretreatment and Extraction Parameters for the Analysis of Fentanyl in Hair Using Statistical Design of Experiments (DoE)

Abstract

Optimal methods for hair analysis are often debated. Previous work in this laboratory demonstrated that the statistical technique known as Design of Experiments (DoE) is useful for such optimization. DoE evaluates both the individual roles and the combinatorial associations among multiple independent variables (i.e., hair pretreatment parameters) and a dependent variable (i.e., drug recovery from hair). In this study, hair externally contaminated with fentanyl underwent decontamination with combinations of parameters based on a 24 fractional factorial block design DoE matrix. The parameters of interest included aqueous wash solvent (1% SDS or water), organic wash solvent (dichloromethane or methanol), number of consecutive washes (one or three), sequence of washes (aqueous first or organic first), and wash time (30 s or 30 min). The optimal method for decontaminating fentanyl from the hair surface was found to be one 30-min wash with dichloromethane followed by one 30-min wash with water. Pretreatment parameters were optimized with a 23 full factorial DoE matrix using authentic hair reference material (HRM), which consisted of pooled drug user hair diluted to a known concentration of fentanyl with drug-free hair. The factors of interest were extraction solvent/sample weight ratio (12.5 or 25 µL/mg), hair particle size (pulverized or 1 mm segments), and extraction time (2 or 24 h). The most effective pretreatment method for fentanyl consisted of pulverizing the hair prior to a 2-h extraction in a 25 µL/mg extraction solvent volume/sample weight ratio. Finally, using the optimized pretreatment methods, fentanyl containing authentic HRM was extracted using aqueous base, solvent, and enzymatic hair extraction methods, where it was determined that the aqueous base technique was most effective for recovery of fentanyl. These experiments further demonstrate the value of DoE and authentic HRM in method development for forensic hair analysis.

Multifunctional Hair Dyeing with Curcumin via Thiol-Michael Click Reaction

“…Virgin black Chinese hair (18 cm × 1 g, free 16 cm) and 2× bleached Chinese hair (18 cm × 1 g, free 16 cm) samples were purchased from Shanghai Canyu Commercial Co., Ltd., (Shanghai, China). Before use, each 1 g hair sample underwent rapid soaking three times in a 100 mL solution of 10% (w/v) sodium dodecyl sulfate (SDS) and was then rinsed with tap water to eliminate impurities . They were dried and stored under ambient conditions (temperature = 298 ± 2 K, RH = 50% ± 5%).…”

“…Before use, each 1 g hair sample underwent rapid soaking three times in a 100 mL solution of 10% (w/v) sodium dodecyl sulfate (SDS) and was then rinsed with tap water to eliminate impurities. 18 They were dried and stored under ambient conditions (temperature = 298 ± 2 K, RH = 50% ± 5%).…”

Genipa americana L.: A New Phytochemical for White Hair Coloring

“…The sample was previously submitted to macroscopic analyses that selecting fibers with color uniformity and absence of damage in the wires (double ends). The samples were washed with 100 mL of 2 % (w/v) sodium dodecyl sulfate solution and rinsed with tap water to remove impurities [46] . They were dried and storage at relative humidity of 50±5 %, for 24 h before the analysis.…”

“…The samples were washed with 100 mL of 2 % (w/v) sodium dodecyl sulfate solution and rinsed with tap water to remove impurities. [46] They were dried and storage at relative humidity of 50 � 5 %, for 24 h before the analysis. The hair fibers were separated in black (BH) and white (WH) color fibers and tresses with 10 fibers each and 7 cm of length were prepared.…”