A novel framework of a probabilistic-based mixture regression model (PMRM) is presented for alignment of multiple liquid chromatography-mass spectrometry (LC-MS) data with respect to retention time (RT) and mass-to-charge ratio (m/z). The expectation maximization algorithm is used to estimate the joint parameters of spline-based mixture regression models and prior transformation density models....

BACKGROUND: Information on absorption and metabolism of strawberry polyphenols is limited. OBJECTIVE: The aim of this study was to characterize and quantify plasma polyphenols/anthocyanins across 4 doses of strawberry using Q-TOF LC/MS and LC-MS/MS analysis. METHOD: Plasma was collected from 5 subjects (n= 5) every 30–60 min for 6 h after consuming beverages containing 0, 10, 20 or 40 g freeze-...

Summary: Developing liquid chromatography tandem mass spectrometry (LC-MS/MS) analyses of (bio)chemicals is both time consuming and challenging, largely because of the large number of LC and MS instrument parameters that need to be optimized. This bottleneck significantly impedes our ability to establish new (bio)analytical methods in fields such as pharmacology, metabolomics and pesticide rese...

The routine adoption of liquid chromatography-tandem mass spectrometry (LC/MS/MS) for clinical research is rapidly gaining momentum. In order to realize the full benefits of adopting LC/MS/MS for analytical measurement, the sample preparation procedure needs to be inexpensive and simple to implement. For challenging applications such as the quantitative measurement of low-level steroids, immuno...

BACKGROUND The accurate and precise measurement of urinary albumin is critical, since even minor increases are diagnostically sensitive indicators of renal disease, cardiovascular events, and risk for death. To gain insights into potential measurement biases, we systematically compared urine albumin measurements performed by LC-MS, a clinically available immunoturbidimetric assay, and size-excl...

Liquid chromatography mass spectrometry (LC-MS) is a widely used technique in the clinical laboratory, especially for small molecule quantitation in biological specimens, for example, steroid hormones and therapeutic drugs. Analysis of circulating macromolecules, including proteins and peptides, is largely dominated by traditional enzymatic, spectrophotometric, or immunological assays in clinic...

Remarkable methodological advances in the past decade have expanded the application of liquid chromatography coupled with mass spectrometry (LC/MS) analysis of biotherapeutics. Currently, LC/MS represents a promising alternative or supplement to the traditional ligand binding assay (LBA) in the pharmacokinetic, pharmacodynamic, and toxicokinetic studies of protein drugs, owing to the rapid and ...

MOTIVATION Liquid chromatography-mass spectrometry (LC-MS) has been widely used for profiling expression levels of biomolecules in various '-omic' studies including proteomics, metabolomics and glycomics. Appropriate LC-MS data preprocessing steps are needed to detect true differences between biological groups. Retention time (RT) alignment, which is required to ensure that ion intensity measur...

A novel framework of a probabilistic-based mixture regression model (PMRM) is presented for alignment of multiple liquid chromatography-mass spectrometry (LC-MS) data with respect to retention time (RT) and mass-to-charge ratio (m/z). The expectation maximization algorithm is used to estimate the joint parameters of spline-based mixture regression models and prior transformation density models....