Vitamin D levels and relative insufficiency in Saskatchewan.

Objective: To determine the extent of vitamin D3 deficiency and levels in pregnant First Nations and non-First Nations women in SK. Also, to determine the distribution of vitamin D3 values in the general population in SK.

Methods: Vitamin D3 levels were measured by LC-MS/MS from 19,181 consecutive patient blood/serum samples received at the Saskatchewan Disease Control Laboratory, and from 743 First Nations, and 301 non-First Nations pregnant women in SK.

Opiate screening and quantitation in urine/blood matrices using LC-MS/MS techniques.

Here we describe a high-volume urinary screening technique for opiate drugs as well as other narcotic analgesics. We also describe methods for quantification of the same drug species in serum, plasma, and whole blood. Screening and quantitation of these types of drugs have presented many challenges, among them the potentially low levels in both abuse and therapeutic situations.

LC-MS/MS techniques for high-volume screening of drugs of abuse and target drug quantitation in urine/blood matrices.

Liquid chromatography-tandem mass spectrometry, employing electrospray ionization (ESI), has been applied in the analysis of many drugs and drug metabolites. Sample preparation has been an important part of this technique when analyzing biological samples. Here we describe a high-volume urine screening technique for approximately 40 different drugs of abuse as well as methods for quantification of many other drugs in serum, plasma, and whole blood.

Elevated neonatal 3-OH isovalerylcarnitine due to breast milk sources in maternal 3-MCC deficiency.

We report a positive newborn screen for 3-hydroxyisovalerylcarnitine (C(5)OH) with an absence of 3-methylcrotonyl-coenzyme A carboxylase deficiency in the neonate. Subsequent blood tests demonstrated persistently elevated C(5)OH. Serial testing of the mother identified markedly elevated C(5)OH in both maternal blood and breast milk.

Drugs of abuse testing by tandem mass spectrometry: a rapid, simple method to replace immunoassays.

Primary Objective: To replace immunoassay screening for drugs of abuse (DOA) with a cost-effective tandem mass spectrometry method.

Secondary Objective: To substantially expand the drugs of abuse assay menu.

Design And Methods: The requirement was to perform high throughput DOA screening for 200 urine specimens/day for 40 drugs/metabolites.

Formate pharmacokinetics during formate administration in folate-deficient young swine.

The objective of the study was to investigate the effect of folate deficiency on formate pharmacokinetics during formate administration in folate-deficient young swine. Methanol is a one of the congeners found in alcoholic beverages. Methanol toxicity is mediated through formic acid and thus plays a significant role in the pathophysiology of alcoholism.

Quantitative endogenous formate analysis in plasma using headspace gas chromatography without a headspace analyzer.

The objective was to develop a simple routine method for quantitative measurement of endogenous formic acid in plasma and whole blood using headspace gas chromatography-flame ionization detection. (GC-FID). Two-hundred microliters of sample was placed in a 1-mL glass vial.

Clinical determination of 17-hydroxyprogesterone in serum by LC-MS/MS: comparison to Coat-A-Count RIA method.

17alpha-Hydroxyprogesterone is a metabolic precursor of cortisol; elevated levels of 17alpha-hydroxyprogesterone are indicative of congenital adrenal hyperplasia. Traditional determination by immunoassay is plagued by poor antibody specificity, resulting in significant interferences. This study explores an LC-MS/MS method for the quantitation of 17OHP in serum.