Detection of a New Tert-Leucinate Synthetic Cannabinoid 5F-MDMB-PICA and Its Metabolites in Human Hair: Application to Authentic Cases

Methyl 2 -[ [ 1- (5- fluoropentyl) indole - 3- carbonyl] amino] -3, 3- dimethyl - butanoate (5F-MDMB-PICA) is a new synthetic cannabinoid characterized by valinate or tert-leucinate moieties. In recent years, 5F-MDMB-PICA has been abused in the form of “spice-like” herbal incenses or electronic cigarette oil. A UHPLC-MS/MS method was developed to detect 5F-MDMB-PICA and its metabolites in human hair. Approximately 20 mg of hair was weighed and pulverized with methanol below 4°C. After ultrasonication, centrifugation and filtration, 200 μL of supernatant was placed into an autosampler vial and analyzed on a Waters Acquity UPLC HSS T3 column (100 mm × 2.1 mm, 1.8 μm particle size) using an acetonitrile-20 mmol/L ammonium acetate (0.1% formic acid, 5% acetonitrile) gradient with a run time of 8 min. The limit of detection (LOD) ranged from 0.5 to 5 pg/mg, and the lower limit of quantitation (LLOQ) ranged from 1 to 5 pg/mg. The method was shown to be linear over a concentration range of 1–200 pg/mg. The linear correlation (R2) of the calibration curves for all analytes was >0.999. The accuracy varied from 95.4 to 107.4%, while the intra- and inter-day precision RSD values were 0.7–10.6% and 1.7–12.2%, respectively. Recoveries were within the range of 61.1–93.3%, and matrix effects were in the range of 19.1–102.6%. The validated method was successfully applied to the identification and quantification of 5F-MDMB-PICA and its metabolites in hair from authentic forensic cases.

Separation of rat tissue histone H1 subtypes by reverse-phase h.p.l.c. Identification and assignment to a standard H1 nomenclature

H1 histones from rat liver and rat testis were separated by reverse-phase h.p.l.c. Within 40 min six subfractions (H1(0), H1b, H1a, H1d, H1e + H1c and H1c) and seven subfractions (H1(0), H1b, H1a, H1d, H1e + H1c, H1c and H1t) respectively were isolated by using a linear acetonitrile gradient. Each individual H1 subtype was identified either by comparing the H1 variants (contained in both tissues but in different quantities) or by SDS/PAGE and acetic acid/urea/PAGE. Moreover, all H1 variants were characterized by amino acid analyses. The amino acid compositions of rat histone subfractions H1(0), H1b and H1e were determined for the first time. It was possible to classify unambiguously the H1 subfractions obtained by h.p.l.c. by following the standardized H1 nomenclature for electrophoretic systems recommended by Lennox, Oshima & Cohen [(1982) J. Biol. Chem. 257, 5183-5189]. Incorrect assignments that have been made in various publications are discussed.

Amino Acid Composition of Cockroach Hypertrehalosaemic Hormones

Hypertrehalosaemic hormones I and II from the corpus cardiacum of the American cockroach (Periplaneta americana) were separated by reversed-phase high-performance liquid chromato­graphy using a Nucleosil C18 column with a trifluoroacetic acid/acetonitrile gradient. The eluent was monitored at 206 nm and the hypertrehalosaemic activity detected by bioassay. The amino acid compositions of hypertrehalosaemic hormone I and II were determined after acid hydrolysis with HCl or methanesulfonic acid. Both neurohormones are octapeptides. Hypertrehalosaemic hormone I contained the amino acids Asp(2), Ser, Glu, Pro, Val, Phe and Trp, whereas hyper­trehalosaemic hormone II contained the amino acid residues Asp, Thr(2), Glu, Pro, Leu, Phe and Trp.

Liquid Chromatographic Determination of Glucosinolates in Rapeseed as Desulfoglucosinolates

A method was developed for the quantitative determination of rapeseed glucosinolates as the desulfo derivatives, using liquid chromatography. Glucosinolates were desulfated at 37°C with the enzyme aryl sulfatase in Tris buffer, pH 8.0. All glucosinolates present in rapeseed were separated in 30 min on a Waters C18 Z-module using an acetonitrile gradient at 4 mL/min. Recoveries of benzyl, 4-hydroxybenzyl, and allylglucosinolates added to plant extracts were quantitative.

High Perform ance Liquid Chrom atographie Analysis o f Steroidal Saponins from Avena sativa L

Reversed phase high performance liquid chromatography offers an efficient and rapid method for analysis of steroidal saponins. Crude extracts from primary leaves of Avena sativa and isolated etioplasts therefrom have been resolved into four saponins (avenacosides) using a water-acetonitrile gradient system on RP-8 and monitoring the column effluent at 200 nm with an UV-detector. Detectability was found to be in the range of 50 ng avenacoside B and the detector response was linear up to 8 μg tested. The described method is applicable to studies on localization and physiology of Avena saponins during development of the primary leaf.