Gas Chromatography Mass Spectrometry (GC‐MS) for Identification of Designer Stimulants Including 2C Amines, NBOMe Compounds, and Cathinones in Urine

Phenethylamine derivatives are being increasingly exploited for recreational use as “designer” stimulants designed to mimic psychostimulant properties of amphetamine or other illicit substances like 3,4‐methylenedioxymethamphetamine (MDMA [ecstasy]). Clandestine operations meticulously design phenethylamines so the user can bypass legal action when detected, as many of these are yet to be regulated by government authorities. Substituted phenethylamines or 2C amines, N‐methoxybenzyl derivatives of the corresponding 2C amines commonly known as NBOMe compounds, and cathinones are among the most commonly abused phenethylamines. Current FDA‐approved assays used in screening for illicit drug use lack the sensitivity needed to detect designer stimulants making it challenging for toxicologists to accurately identify these compounds. Gas chromatography mass spectrometry (GC‐MS) is a sensitive method for identifying designer stimulants. This unit describes and compares two qualitative GC‐MS methods for identifying 2C amines, NBOMe compounds, and cathinones in urine. © 2017 by John Wiley & Sons, Inc.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152516/1/cptx0443.pd

10 years of 25-hydroxyvitamin-D testing by LC-MS/MS-trends in vitamin-D deficiency and sufficiency

In early 2000's vitamin-D deficiency was shown to be prevalent in several countries including the United States (US). Studies exploring the role of vitamin-D metabolism in diverse disease pathways generated an increased demand for vitamin-D supplementation and an immense public interest in measurement of vitamin-D metabolite levels. In this report, we review the role of vitamin-D metabolism in disease processes, clinical utility of measuring vitamin-D metabolites including 25-hydroxyvitamin-D (25(OH)D), 1,25-dihydroxyvitamin-D and 24,25-dihydroxyvitamin-D and discuss vitamin-D assay methodologies including immunoassays and liquid chromatography mass spectrometry (LC-MS/MS) assays. We also provide examples of vitamin-D toxicity and insight into the trends in serum 25(OH)D levels in the US population based on 10 years of data from on serum 25(OH)D values from ~5,000,000 patients who were tested at the Mayo Medical Laboratories between February 2007–February 2017. Keywords: Vitamin D supplementation trends, LC-MS/MS, Vitamin D toxicit

Altered Calcium and Vitamin D Homeostasis in First-Time Calcium Kidney Stone-Formers.

Elevated serum 1,25-dihydroxyvitamin D (1,25(OH)2D) concentrations have been reported among cohorts of recurrent calcium (Ca) kidney stone-formers and implicated in the pathogenesis of hypercalciuria. Variations in Ca and vitamin D metabolism, and excretion of urinary solutes among first-time male and female Ca stone-formers in the community, however, have not been defined.In a 4-year community-based study we measured serum Ca, phosphorus (P), 25-hydroxyvitamin D (25(OH)D), 1,25(OH)2D, 24,25-dihydroxyvitamin D (24,25(OH)2D), parathyroid hormone (PTH), and fibroblast growth factor-23 (FGF-23) concentrations in first-time Ca stone-formers and age- and gender frequency-matched controls.Serum Ca and 1,25(OH)2D were increased in Ca stone-formers compared to controls (P = 0.01 and P = 0.001). Stone-formers had a lower serum 24,25(OH)2D/25(OH)D ratio compared to controls (P = 0.008). Serum PTH and FGF-23 concentrations were similar in the groups. Urine Ca excretion was similar in the two groups (P = 0.82). In controls, positive associations between serum 25(OH)D and 24,25(OH)2D, FGF-23 and fractional phosphate excretion, and negative associations between serum Ca and PTH, and FGF-23 and 1,25(OH)2D were observed. In SF associations between FGF-23 and fractional phosphate excretion, and FGF-23 and 1,25(OH)2D, were not observed. 1,25(OH)2D concentrations associated more weakly with FGF-23 in SF compared with C (P <0.05).Quantitative differences in serum Ca and 1,25(OH)2D and reductions in 24-hydroxylation of vitamin D metabolites are present in first-time SF and might contribute to first-time stone risk

Serum analytes and hormones (PTH, 25(OH)D, 1,25(OH)₂D, 24,25(OH)₂D and FGF-23) and urine analytes in calcium stone-formers and controls.

<p>All values are represented as mean ± standard error. CSF = confirmed; TSF = total (confirmed plus presumed calcium SF).</p

Dietary intake variables in calcium stone-formers and controls.

<p>* FFQ were not available on all subjects.</p><p>All values are represented as mean ± standard error. CSF = confirmed; TSF = total (confirmed plus presumed calcium SF).</p

Urine Ca and serum analytes in male and female normocalciuric SF (NC; males, U Ca <250 mg/ 24 h; females U Ca <200 mg/24 h) or hypercalciuric SF (HC; male U Ca >250 mg/24 h; female U Ca > 200 mg/24 h); mean +/- SEM.

<p>Urine Ca and serum analytes in male and female normocalciuric SF (NC; males, U Ca <250 mg/ 24 h; females U Ca <200 mg/24 h) or hypercalciuric SF (HC; male U Ca >250 mg/24 h; female U Ca > 200 mg/24 h); mean +/- SEM.</p