Determination of lidocaine in urine at low ppm levels using dispersive microextraction and attenuated total reflectance–Fourier transform infrared measurements of dry films
Abstract IR spectra provide valuable information about biological systems and can be obtained with compactable and affordable instruments, but the lack of sensitivity of this technique hampers its use in the determination of drugs in clinical fluids. Taking lidocaine as a target molecule, in this paper we introduced a methodology for determining drugs in urine samples using infrared spectroscopy. The lack of sensitivity of the IR was compensated with the combination of an effective and straightforward dispersive liquid–liquid microextraction and the measurement of the dry film of the organic extracts through attenuated total reflectance (ATR). The method developed improves the sensitivity b…
On-Capillary Surface-Enhanced Raman Spectroscopy: Determination of Glutathione in Whole Blood Microsamples.
Oxidative stress monitoring in the neonatal period supports early outcome prediction and treatment. Glutathione (GSH) is the most abundant antioxidant in most cells and tissues, including whole blood, and its usefulness as a biomarker has been known for decades. To date, the available methods for GSH determination require laborious sample processing and the use of sophisticated laboratory equipment. To the best of our knowledge, no tools suitable for point-of-care (POC) sensing have been reported. Surface-enhanced Raman spectroscopy (SERS), performed in a microvolume capillary measurement cell, is proposed in this study as a robust approach for the quantification of GSH in human whole blood…
Does Pasteurized Donor Human Milk Efficiently Protect Preterm Infants Against Oxidative Stress?
International audience; Pasteurized donor human milk (DHM) is the preferred alternative for infant nutrition when own mother's milk (OMM) is unavailable. Whether DHM is an efficient means for protecting preterm infants from oxidative stress remains unknown. We quantified a panel of oxidative stress biomarkers in urine samples from preterm infants (≤32 weeks of gestation and a birth weight ≤1500 g) receiving ≥80% of feeding volume as either DHM or OMM. The noninvasive in vivo assessment of oxidative stress showed no statistically significant difference between both groups at the time when full enteral nutrition (150 mL/kg body weight) was achieved and until hospital discharge. In addition, t…
Chemometric determination of lipidic parameters in serum using ATR measurements of dry films of solvent extracts
Attenuated total reflectance (ATR) infrared spectroscopy of dried organic extracts of serum samples has been evaluated as a fast method for the determination of triglycerides, cholesterol, high density lipoprotein (HDL) and low density lipoprotein (LDL). After careful selection of solvents based on green parameters, serum samples were extracted using hexane-isopropanol and ethyl acetate-ethanol mixtures. Microscopy studies and comparison with standard spectra were performed in order to investigate whether the proposed methodology is suitable for the quantification of lipids in serum samples. The results of these preliminary studies confirmed that the variations in the IR spectra of sample e…
Analysis of multi-source metabolomic data using joint and individual variation explained (JIVE).
Metabolic profiling is increasingly being used for understanding biological processes but there is no single analytical technique that provides a complete quantitative or qualitative profiling of the metabolome. Data fusion (i.e. joint analysis of data from multiple sources) has the potential to circumvent this issue facilitating knowledge discovery and reliable biomarker identification. Another field of application of data fusion is the simultaneous analysis of metabolomic changes through several biofluids or tissues. However, metabolomics typically deals with large datasets, with hundreds to thousands of variables and the identification of shared and individual factors or structures acros…