Paul D Rainville

• Waters Corporation

Background Melatonin supplements are often used to alleviate jetlag and other sleep-depletion related disorders. Recent studies found large inconsistencies between labeled values and actual contents of melatonin within products, which has led to concerns over the quality of melatonin supplements. In order to facilitate the quality control testing o...

This work aimed to develop an analytical method for the screening of multiple aminoglycoside residues in foods of animal origin using an ethylene-bridged hybrid (BEH) particle-based sulfoalkylbetaine stationary phase. The effects of chromatographic conditions on the separation of 17 aminoglycosides have been systematically investigated. Sample prep...

abstract Properly implemented, metabolic and lipidomic profiling can provide a deeper understanding of mammalian, plant and bacterial biology. These omics-tools have developed and matured over the last 40-years and are now being deployed to provide valuable information in epidemiological studies, drug toxicology and pharmacology, disease biology an...

The use of vacuum jacketed LC columns (VJC) to minimize on- and post-column band broadening to maximize chromatographic performance has been evaluated as a potential route to improved high throughput (HT) analysis. Here the use of the “VJC” approach has been applied to the HT bioanalysis of the antidiabetic GPR40 agonist drug fasiglifam in rat plas...

Background: Baseline separation of nonivamide (NON) and capsaicin (CAP) has not been achieved by using the existing liquid chromatography (LC) methods for the capsaicinoid analysis. This could lead to large errors in the determination of capsaicinoids for capsicum products. Objective: The development of an ultrahigh-performance liquid chromatogr...

Recently, a novel hybrid surface technology (HST) has been developed to mitigate metal analyte adsorption in liquid chromatography. The HST provides a hybrid organic–inorganic surface on the metal fluidic path, from injection to detector and including the column frits and wall, to mitigate the interaction between analytes and metals. Here the impac...

Metabolic phenotyping studies using mouse liver extracts as a model, performed on a novel zwitterionic HILIC UHPLC column, which is based on ethylene-bridged hybrid organic/inorganic particles bonded with sulfobetaine groups and packed into column hardware modified with hybrid surface technology are reported. Initially the chromatographic performan...

Reversed-phase UHPLC-MS is extensively employed for both the profiling of biological fluids and tissues to characterize lipid dysregulation in disease and toxicological studies. With conventional LC-MS systems the chromatographic performance and throughput are limited due to dispersion from the fluidic connections as well as radial and longitudinal...

Reversed‐phased liquid chromatography (LC) separation methods are developed for all kinds of chromatographic assays. Their performance is critical for ensuring the quality, safety, and efficacy of pharmaceutical products; monitoring clinical patient parameters, food contents, and contaminants; screening environmental samples for toxins or any other...

In UHPLC, frictional heating from the eluent flowing through the column at pressures of ca. 10-15 Kpsi causes radial diffusion via temperature differences between the center of the column and its walls. Longitudinal dispersion also occurs due to temperature gradients between the inlet and outlet. These effects cause band broadening but can be mitig...

The accurate determination of the pharmacokinetics (PK) of a candidate drug molecule is critical in both drug discovery and development. Over the last 30 years, the sensitivity and selectivity of LC/MS has resulted in it being established as the technology of choice for these studies. However, unwanted chemical interactions between analyte(s) and t...

An LC-MS method was developed for routine determination of lactose in low-lactose and lactose-free dairy products. The lactose was separated on an amide column under an isocratic elution condition. Baseline separation of lactose from common interferents, including epilactose, lactulose, and allolactose were achieved under this LC conditions. The la...

We describe a method for the analysis of organic acids, including those of the tricarboxylic acid cycle (TCA cycle), by mixed-mode reversed-phase chromatography, on a CSH Phenyl-Hexyl column, to accomplish mixed-mode anion-exchange separations, which results in increased retention for acids without the need for ion-pairing reagents or other mobile...

The incorporation of ion mobility (IM) into LC-MS analysis has been demonstrated to result in the generation of superior quality MS and MS/MS spectral data as well as providing enhanced resolution in the IM dimension based on lipid class. Here a sub 4 min microbore LC-ion mobility-accurate mass MS (LC-IM-MS) method has been developed for the rapid,...

The application of a data independent acquisition (DIA) method ("SONAR") that employs a rapidly scanning quadrupole, for the lipidomic analysis of complex biological extracts is described. Using this approach the MS acquisition window can be varied between 1-25 Da enabling the isolation of ions prior to their entering the collision cell. By rapidly...

Introduction As large scale metabolic phenotyping is increasingly employed in preclinical studies and in the investigation of human health and disease the current LC–MS/MS profiling methodologies adopted for large sample sets can result in lengthy analysis times, putting strain on available resources. As a result of these pressures rapid methods of...

Capillary scale (100 mm × 150 μm id) UPLC/MS/MS, performed using reversed-phase gradient chromatography on sub 2 μm particles, has been successfully employed for the characterization of the metabolites of the drug tienilic acid (TA) excreted via the urine following oral administration to the rat. The capillary LC system provided a significant incre...

Liquid chromatography-mass spectrometry (LC-MS, and variants such as supercritical fluid chromatography-mass spectrometry (SFC-MS)) is widely used to derive characteristic metabolic phenotypes using untargeted approaches to perform unbiased global metabolic profiling. Currently, applications in this area are mainly undertaken using reversed-phase (...

The need for rapid and efficient high throughput metabolic phenotyping (metabotyping) in metabolomic/metabonomic studies often requires compromises to be made between analytical speed and metabolome coverage. Here the effect of column length (150, 75 and 30 mm) and gradient duration (15, 7.5 and 3 min respectively) on the number of features detecte...

Prostate cancer (PCa) is the most prevalent cancer amongst men and the second most common cause of cancer related-deaths in the USA. Prostate cancer is a heterogeneous disease ranging from indolent asymptomatic cases to very aggressive life threatening forms. The goal of this study was to identify differentially expressed metabolites and lipids in...

An integrated capillary scale (300 μm id) ceramic microfluidic LC system combined with MS/MS has been successfully employed for the quantitative analysis of pharmaceutical compounds in human plasma. The capillary ceramic microfluidic LC/MS/MS system showed an approximate 20-fold (range 11-38-fold) increase in sensitivity compared with a standard 2....

Capillary LC (cLC) coupled to MS has the potential to improve detection limits, address limited sample volumes and allow multiple analyses from one sample. This is particularly attractive in areas where ultrahigh assay sensitivity, low limits of detection and small sample volumes are becoming commonplace. However, implementation of cLC-MS in the bi...

Increased pressure to obtain more, higher sensitivity data from less sample is especially critical for large peptides, whose already optimized LC-MS methods are heavily challenged by traditional ligand-binding assays. Critical bioanalytical assays were adapted to integrated microscale LC to reduce sample volumes while increasing sensitivity. Assays...

The emergence of micro sampling techniques holds great potential to improve pharmacokinetic data quality, reduce animal usage, and save costs in safety assessment studies. The analysis of these samples presents new challenges for bioanalytical scientists, both in terms of sample processing and analytical sensitivity. The use of two dimensional LC/M...

We review the separations currently employed in the field of global metabolic profiling and based on the use of liquid chromatography (LC) coupled to mass spectrometry. Currently, most LC separations are performed using reversed-phase (RP) methods, with hydrophilic interaction chromatography a popular choice for polar compounds that are not well se...

Waters Application Note - 720005182EN - http://www.waters.com/webassets/cms/library/docs/720005182en.pdf - For quantitative analysis, Waters has introduced a new target-enhancement mode of data acquisition, Tof-MRM, on the SYNAPT G2-S HDMS and Xevo G2-XS mass spectrometers. In the presence of human plasma, Tof-MRM mode can achieve on-column limits...

Embodiments of the present invention feature a device (1) and method for performing steps of a multi-step process in parallel. The device (1) and method feature a rotor assembly (13) having vessel stations (33) and stator assembly (15) having work positions. The rotor assembly (13) rotates the vessels (17) to the work stations to perform steps of a...

In this study, sub-2 µm particle CO2 based supercritical chromatography was investigated for the separation of free fatty acids, neutral and polar lipids in cottonseed extract. Typically, plant metabolomic profiling distinguishes heterogeneous distribution of neutral lipids; such as triacylglycerols and diacylgylcerols at different conditions. The...

Ultra high resolution SFC-MS (on sub-2μm particles) coupled to mass spectrometry has been evaluated for the metabolic profiling of rat and dog bile. The selectivity of the SFC separation differed from that seen in previous reversed-phase UPLC-MS studies on bile, with the order of elution for analytes such as e.g., the bile acids showing many differ...

Background: Accurate mass based LC-MS combined with statistical analysis is established as a core analytical technology for metabonomic studies. This is primarily due to the specificity, sensitivity and structural elucidation capabilities of the technology. The vast majority of these studies are performed using acidic-based mobile phases in combin...

Bioanalytical methods often involve the quantification of a parent compound to determine the pharmacokinetic properties of a potential drug. In some cases, it may also be necessary to quantify a metabolism product in addition to the parent molecule as these may be either active or toxic. Simultaneous determination can be challenging because of diff...

The movement towards environmentally friendly or green chemistry solutions has gained more prominence recently in the scientific community. One way in which scientists can address this issue is to limit the use of hazardous chemicals in their everyday processes. Therefore, the focus of this study was on the utilization of microbore-scale chromatogr...

The quantification of proteins and peptides in in vivo samples is a critical part of supporting the drug development process for biotherapeutics. LC-MS/MS using tandem quadrupole mass spectrometers is well established as the technology of choice for the quantification of small-molecule drugs and their metabolites in biological fluid. The applicatio...

The sensitivity and accuracy of a bioanalytical method is critical in defining the pharmacokinetic (PK) parameters of a potential new chemical entity (NCE). Inhaled therapeutics and low dose NCEs present one of the most significant analytical challenges to the bioanalyst, due to their low systemic concentration. The sensitivity of a bioanalytical L...

Miniaturization of chromatographic separation systems provides a means of greatly increasing sensitivity in LC-MS. In this article, we demonstrate the use of an integrated microfluidic chromatographic device for the LC-MS/MS investigation of the in vitro microsomal metabolism of the model drug propranolol using a sample volume of 1 µl of a 1-µM inc...

The use of dried blood and dried plasma spots for storage and transportation of samples derived from clinical trials holds the promise to reduce cost, simplify storage and shipping as well as reducing animal usage. From the bioanalysts' point of view, these dried-paper samples add an extra layer of complexity to the analysis introducing extra matri...

The profiling and quantification of drug metabolites in discovery and development bioanalysis studies is playing an increasingly important role in early candidate selection. Using a conventional tandem quadrupole mass spectrometer this activity normally requires several analytical runs to acquire the necessary analytical data. In this article we pr...

A rapid, specific, assay was developed for the benzodiapine alprazolam in rat plasma using sub-2 µm particle liquid chromatography (LC) and tandem quadrupole mass spectrometry (MS/MS). The limit of quantification using protein precipitation was determined to 10 pg/mL, whereas the limit of quantification using solid-phase extraction (SPE) was determ...

Drug-drug interaction evaluations of new pharmaceutical candidates are critical to preventing drug withdrawal and are routinely determined through the use of cytochrome P450 assays. The measurement of the effect of test compounds on the metabolism of known substrates allows for the determination of specific CYP450 isoenzyme inhibition and calculati...

Reversed-phase gradient UPLC-ESI-MS, in both positive and negative ionization modes, has been applied to the analysis of untreated bile obtained from bile-cannulated rats and dogs. The use of UPLC provided a high-resolution system that enabled global metabolite profiles of bile from the two species to be obtained that were suitable for metabolomic...

High-throughput ADME screening for compound drug development properties has become an essential part of the modern drug discovery process, allowing more informed decisions to be made on the best compounds to take forward in the discovery/development process. This however is a time-consuming process requiring multiple tests to be performed, demandin...

The measurement of cytochrome P450 (CYP450) isoenzyme inhibition is often done during evaluation of new chemical entities in drug discovery. Typical assay protocol consists of multiple CYP450 probe substrates incubated with selected drug candidates and CYP450. Results of the assay, the amount of probe substrate metabolite formed with respect to con...

The comparison of batches of pharmaceutical product or raw active pharmaceutical ingredients (API) for product release can be time consuming and tedious process. It often requires long analysis times and potentially several liquid chromatography-tandem mass spectrometry (LC-MS-MS) analytical runs to determine the identity of the impurities and thei...

The application of sub-2 microm porous particle liquid chromatography (LC) operated at elevated temperatures, coupled with time-of-flight mass spectrometry (MS), to the separation and identification of metabolites of ibuprofen present in human urine following oral administrations is illustrated. The LC/MS system generated a high-resolution analytic...

The profiling and identification of impurities in raw pharmaceuticals or finished drug product is an essential part of the pharmaceutical manufacturing process. Critical to this process is the ability to confirm known, expected impurities and identify new impurities. LC coupled to electrospray MS is a powerful tool that has been employed for the id...

The metabonomic effects of hepatotoxic doses of pravastatin on the urinary metabolic profiles of female rats have been investigated using ultra performance liquid chromatography (UPLC)-oa-TOF-MS and, independently, by (1)H NMR spectroscopy. UPLC was performed using a 1 mm microbore column packed with 1.7 microm particles. Examination of the data ob...

The effect of combining sub-2 microm porous particles with elevated operating temperatures on chromatographic performance has been investigated in terms of chromatographic efficiency, productivity, peak elution order, and observed operating pressure. The use of elevated temperature in LC does not increase the obtainable performance but allows the s...

Ultra-Performance LC (UPLC) utilizing sub-2-mum porous stationary phase particles operating with high linear velocities at pressures >9000 psi was coupled with orthogonal acceleration time-of-flight (oaTOF) mass spectrometry and successfully employed for the rapid separation of lipids from complex matrices. The UPLC system produced information-rich...

The use of a combination of ultraperformance liquid chromatography at approximately 11,000 psi on sub 2-microm particles combined with reversed-phase gradient chromatography at a temperature of 90 degrees C is described as applied to the analysis of endogenous and drug metabolites in human and animal urine. By using elevated temperatures, back pres...

Analysis of biological fluids using ultra-performance liquid chromatography/mass spectrometry (UPLC/MS) (metabonomics) can allow new insights to be gained into disease processes, with advances in chromatographic techniques enabling the detection of thousands of metabolites. In this work metabonomics has been used to investigate the metabolic proces...

A new analytical strategy for biomarker recovery from directly coupled ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC Tof MS) data on biofluids is presented and exemplified using a study on hydrazine-induced liver toxicity. A key step in the strategy involves a novel procedure for reducing the spectroscopic search sp...

A new approach to obtain fragmentation information in liquid chromatography/mass spectrometry (LC/MS) studies of small molecules in complex mixtures is presented using simultaneous acquisition of exact mass at high and low collision energy, MS(E). LC/MS-TOF and LC/MS/MS-TOF are powerful tools for the analysis of complex mixtures, especially those f...

Statistical heterospectroscopy (SHY) is a new statistical paradigm for the coanalysis of multispectroscopic data sets acquired on multiple samples. This method operates through the analysis of the intrinsic covariance between signal intensities in the same and related molecules measured by different techniques across cohorts of samples. The potenti...

The identification of metabolites, whether from in vitro or in vivo samples, is an ongoing challenge in drug discovery and development. Metabolite identification typically uses an array of chromatographic and mass spectrometric methods, and therefore may require multiple analyses of the same sample. This is to ensure that enough information has bee...

Size exclusion chromatography (SEC) coupled with mass spectrometry was used to study heat-induced aggregation in protein mixture.

When cytochrome C tryptic digests were characterized by LC-UV-MS, Atiantis(TM) dC(18) columns were shown to maintain excellent peak shape, resolution, and retention when the "MS-friendly" additive, formic acid, replaced TFA in the mobile phase. Atlantis(TM) dC(18) columns also offer excellent peak shape, resolution, and retention under high mass lo...

An ion-pair reversed-phase HPLC method was evaluated for the separation of synthetic oligonucleotides. Mass transfer in the stationary phase was found to be a major factor contributing to peak broadening on porous C18 stationary phases. A small sorbent particle size (2.5 microm), elevated temperature and a relatively slow flow-rate were utilized to...

Introduction Extreme alcohol consumption in man is socially disruptive and can lead to significant levels of liver injury. In this study a rodent “intragastric feeding model” was used together with accurate mass LC/MS/MS analysis to determine changes in the global metabolic profiles in both plasma and urine. The resulting raw data obtained was an...