Comparison of blood microsampling with DBS and conventional blood collection techniques used in a midazolam biostudy.

BACKGROUND: Quantitative DBS LC-MS/MS assay for midazolam was used to compare two sample collection techniques (venipuncture and finger prick) and the midazolam concentrations measured in plasma samples, DBS and dried plasma spots. METHODOLOGY: Midazolam was extracted from DBS cards and compared with whole blood collected from usual venipuncture. Dried plasma spots were also compared with plasma. The blood volume used as well as the temperature impact during the blood and plasma deposits was evaluated. Midazolam was administrated to six healthy subjects during a clinical trial to obtained blood and plasma samples for the statistical comparison. CONCLUSION: The method for midazolam using DBS was validated and showed an excellent performance. Excellent correlations were observed when the same collection procedures were used.

Recommendations on incurred sample stability (ISS) by GCC.

The topic of incurred sample stability (ISS) has generated considerable discussion within the bioanalytical community in recent years. The subject was an integral part of the seventh annual Workshop on Recent Issues in Bioanalysis (WRIB) held in Long Beach, CA, USA, in April 2013, and at the Global CRO Council for Bioanalysis (GCC) meeting preceding it. Discussion at both events focused on the use of incurred samples for ISS purposes in light of results from a recent GCC survey completed by member companies. This paper reports the consensus resulting from these discussions and serves as a useful reference for depicting ISS issues and concerns, summarizing the GCC survey results and providing helpful recommendations on ISS in the context of bioanalytical method development and application.

Population baseline of meconium fatty acid ethyl esters among infants of nondrinking women in Jerusalem and Toronto.

The detection of fatty acid ethyl esters (FAEE) in meconium may provide an objective estimate of prenatal alcohol exposure independent of maternal history. The authors report the results of the first population-based study conducted to investigate basal FAEE levels in the meconium of neonates not exposed to alcohol. Two hundred seven nondrinking women and their neonates were recruited from Toronto and Jerusalem. FAEE were extracted from meconium by solid-phase extraction and analyzed by GC/FID. Similar procedures were conducted in six neonates born to confirmed heavy drinkers. Low levels of meconium FAEE were detected from both cohorts (mean, 1.37 nmol/g vs. 2.08 nmol/g, Toronto vs. Jerusalem). Ethyl stearate, oleate, and linoleate were below the limit of detection in >80% of all samples, whereas ethyl laurate and palmitate were detected in >50% of the samples. Ethyl myristate was the FAEE most commonly detected (>80%). All six meconium samples with confirmed maternal drinking histories tested positive for FAEE at significantly higher levels (mean, 11.08 nmol/g). The use of 2 nmol total FAEE/g meconium as the positive cutoff, when lauric and myristic acid ethyl esters were excluded, yielded the greatest sensitivity (100%) and specificity (98.4%). The authors conclude that certain FAEE are present at measurable levels in the meconium of neonates not exposed to maternal drinking, and correction is needed to allow high specificity.