Rapid desorption and analysis for illicit drugs and chemical profiling of fingerprints by SICRIT ion source.

Forensic analysis can encompass a wide variety of analytes from biological samples including DNA, blood, serum, and fingerprints to synthetic samples like drugs and explosives. In order to analyze this variety, there are various sample preparation techniques, which can be time-consuming and require multiple analytical instruments. With recent advancements in ambient ionization mass spectrometry (MS), plasma-based dielectric barrier discharge ionization (DBDI) sources have demonstrated to cover a wide range of these analytes. The flow-through design of this source also allows for easy connection to a thermal desorption type of sample introduction. We present an in-house built thermal desorption device where the sample is introduced via a glass slide, which gets heated and transferred to the DBDI-MS with nitrogen for identification and semi-quantification. Using a glass slide as an inexpensive sampling device, detection limits as low as 20 pg for fentanyl are demonstrated. Additionally, a very precise (>96% accuracy) identification of persons based on the chemical profile of their fingerprints is possible, establishing a direct analytical link of the drug trace to the individual in one measurement. We compared the DAG, TAG, sterol, and (semi-)volatile region of the averaged fingerprint spectra over multiple days, showing the best model accuracy for identification based on the DAG region. The combination of thermal desorption and DBDI-MS minimized sample preparation, leading to an ultrasensitive and rapid analysis of illicit drug traces and the identification of underlying personas based on fingerprints.

The unknown lipids project: harmonized methods improve compound identification and data reproducibility in an inter-laboratory untargeted lipidomics study.

Untargeted lipidomics allows analysis of a broader range of lipids than targeted methods and permits discovery of unknown compounds. Previous ring trials have evaluated the reproducibility of targeted lipidomics methods, but inter-laboratory comparison of compound identification and unknown feature detection in untargeted lipidomics has not been attempted. To address this gap, five laboratories analyzed a set of mammalian tissue and biofluid reference samples using both their own untargeted lipidomics procedures and a common chromatographic and data analysis method. While both methods yielded informative data, the common method improved chromatographic reproducibility and resulted in detection of more shared features between labs. Spectral search against the LipidBlast in silico library enabled identification of over 2,000 unique lipids. Further examination of LC-MS/MS and ion mobility data, aided by hybrid search and spectral networking analysis, revealed spectral and chromatographic patterns useful for classification of unknown features, a subset of which were highly reproducible between labs. Overall, our method offers enhanced compound identification performance compared to targeted lipidomics, demonstrates the potential of harmonized methods to improve inter-site reproducibility for quantitation and feature alignment, and can serve as a reference to aid future annotation of untargeted lipidomics data.

Association Between Obesity During Pregnancy and the Adequacy of Prenatal Care.

OBJECTIVE: In the United States, more than a third of women are obese [body mass index (BMI) ≥ 30]. Although obese populations utilize health care at increased rates and have higher health care costs than non-obese patients, the adequacy of prenatal care in this population is not well established and assumed to be suboptimal. We therefore evaluated adequacy of prenatal care among obese women. METHODS: We utilized an electronic database including 7094 deliveries with pre-pregnancy BMI ≥ 18.5 from January 2009 through December 2011. Subjects were categorized as normal weight 18.5-24.9 kg/m2, overweight 25-29.9 kg/m2, and obese ≥30 kg/m2 (class I-II-III). Adequacy of prenatal care (PNC) was evaluated using the Kotelchuck Index (KI), corrected for gestational age at delivery. Adequate care was defined as KI "adequate" or "adequate plus," and non-adequate as "intermediate" or "inadequate." Chi square and logistic regression were used for comparisons. RESULTS: When compared to non-obese women, obese women were more likely to have adequate PNC (74.1 vs. 68.7%; OR 1.30, 95% CI 1.15-1.47). After adjusting for age, race, education, diabetes, hypertension, and practice type, obesity remained a significant predictor of adequate prenatal care (OR 1.29, 95% CI 1.14-1.46). While age and hypertension were not significant independent predictors of adequate PNC, college education, Caucasian, diabetes, and resident or MFM care had positive associations. CONCLUSION: Maternal obesity is associated with increased adequacy of prenatal care. Although some comorbidities associated with obesity increase utilization of prenatal services, this did not explain the improvement in PNC adequacy associated with obesity. SIGNIFICANCE: Overweight and obese women are at a higher risk of pregnancy complications with obesity contributing to increased morbidity and mortality of the mother. Several studies have evaluated barriers to routine health care services, with obese parturients perceiving their weight to be a barrier to obtaining appropriate care. There is limited data available assessing the adequacy of prenatal care in this population. Our study demonstrated that obesity was actually associated with an increased adequacy of prenatal care. The presence of comorbidities did not explain this improvement in prenatal care.