Dosage d'un panel d'anticrises de nouvelle génération par LC-MS/MS / Dosing of a New Generation Anti-Seizure Panel by LC-MS/MS

INTRODUCTION: Une demande d'introduction d'une nouvelle analyse au Répertoire québécois et système de mesure des procédures de biologie médicale (ci-après nommé « Répertoire ¼) a été effectuée par le Centre hospitalier de l'Université de Montréal (CHUM) et transmise à l'Institut national d'excellence en santé et en services sociaux (INESSS) selon le mécanisme d'évaluation des nouvelles analyses de biologie médicale. Le mandat confié vise à évaluer le dosage d'un panel d'anticrises de nouvelle génération par chromatographie liquide couplée à la spectrométrie de masse en tandem (LC-MS/MS) dans le cadre du suivi thérapeutique de l'épilepsie. Étant donné que ce test ne figure pas dans le Répertoire, le ministère de la Santé et des Services sociaux (MSSS) juge nécessaire que la pertinence de cette analyse soit évaluée. MÉTHODOLOGIE: La démarche d'évaluation comprend une revue de la documentation scientifique, une recherche de la littérature grise et des consultations menées auprès de cliniciens et d'autres parties prenantes. La méthodologie a été déployée autour de sept questions d'évaluation, portant notamment sur les dimensions socioculturelle, populationnelle, clinique (validité clinique et utilité clinique), organisationnelle et économique (efficience et impact budgétaire). Une revue de la littérature économique a été réalisée ainsi qu'une évaluation de la possibilité d'effectuer une modélisation économique pour mesurer l'efficience du dosage des anticrises de nouvelle génération par LC-MS/MS. Une analyse d'impact budgétaire considérant les coûts liés à l'introduction du dosage des anticrises de nouvelle génération par LC-MS/MS au Répertoire a été réalisée. Les coûts ont été projetés sur un horizon temporel de trois ans selon la perspective du système de soins de santé. L'ensemble des données scientifiques, contextuelles et expérientielles a été interprété et synthétisé sous la forme de constats afin de guider le processus de délibération du Comité délibératif permanent (CDP) - Approches diagnostiques et dépistage en vue de l'élaboration de recommandations. CONTEXTE DE L'ÉVALUATION: L'épilepsie entraîne des conséquences neurologiques, cognitives, psychologiques et sociales importantes pour les personnes qui en sont atteintes. Le traitement de l'épilepsie est essentiellement pharmacologique. Selon les individus, les médicaments peuvent avoir une efficacité, une innocuité et des effets indésirables variables. Il s'avère donc nécessaire de surveiller l'évolution de cette maladie et d'adapter la prise en charge adéquatement. Un recours au suivi thérapeutique par dosage des anticrises est de plus en plus recommandé. Toutefois, de nombreux autres anticrises largement utilisés ne bénéficient d'aucune procédure de dosage officiellement inscrite au Répertoire. À ce jour, au Québec, le Répertoire ne contient que deux tests correspondant aux dosages des anticrises de nouvelle génération, soit la lamotrigine (30690) et le clobazam (30660). DIMENSION SOCIOCULTURELLE: Le Guide de pratique clinique du gouvernement de l'Ontario sur la prise en charge de l'épilepsie et d'autres documents similaires issus de sociétés savantes à l'international mentionnent que le suivi thérapeutique des anticrises repose sur le jugement clinique du médecin traitant. Bien qu'il ne soit pas recommandé de le faire systématiquement pour tous les patients, le suivi thérapeutique devrait être considéré lorsque les crises ne sont pas contrôlées, qu'une condition altérant la pharmacocinétique comme une grossesse est présente ou encore lorsqu'une toxicité ou une non-observance est suspectée. DIMENSION POPULATIONNELLE: L'épilepsie touche environ 300 000 personnes au Canada et est diagnostiquée à tout âge. L'épilepsie augmente les risques de blessures et de décès prématuré, peut perturber le sommeil, affecter le choix de carrière, limiter la pratique d'activité physique et restreindre le droit de conduire. La stigmatisation liée à l'épilepsie est un défi considérable pour certains patients, ce qui a des répercussions sur leur qualité de vie globale. Les médicaments anticrises demeurent la base du traitement de l'épilepsie. Ils permettent de réduire la fréquence des crises tout en offrant une meilleure qualité de vie aux patients. La concentration plasmatique efficace varie d'un individu à l'autre et ne se retrouve pas nécessairement à l'intérieur d'une plage de référence. Dans ce contexte, l'identification d'une concentration individuelle plasmatique pourrait être souhaitée. Les anticrises ont des effets indésirables qui peuvent gêner la vie quotidienne et doivent être considérés dans la prise en charge. Au Québec, l'offre actuelle de tests pour effectuer le suivi thérapeutique des anticrises de nouvelle génération ne répond pas à la demande des cliniciens. En effet, plusieurs de ces médicaments ne sont pas dosés et le temps réponse pour obtenir le résultat du dosage de ceux qui le sont est jugé inacceptable. DIMENSION CLINIQUE: Malgré un niveau de preuve généralement faible, les études sélectionnées ont indiqué que le dosage des anticrises de nouvelle génération dans le cadre du suivi thérapeutique offrirait quelques avantages cliniques, notamment un meilleur contrôle des crises ou une diminution des effets indésirables. Cela pourrait être particulièrement avantageux pour les patients présentant une variabilité pharmacocinétique accrue, comme les enfants, les personnes âgées, les femmes enceintes et les patients atteints de comorbidités. À la lumière de la littérature scientifique repérée et de l'opinion des experts, la LC-MS/MS est considérée comme une méthode de référence pour effectuer le dosage des anticrises de nouvelle génération à partir d'échantillons de sérum ou de plasma. DIMENSION ORGANISATIONNELLE: La LC-MS/MS offre la possibilité d'analyser à la chaîne un lot d'échantillons provenant de différents patients traités avec un ou plusieurs anticrises, ce qui facilite la centralisation et l'optimisation des procédures. Certains laboratoires détiennent les ressources nécessaires pour doser les anticrises de nouvelle génération selon une approche multiplex en LC-MS/MS. Les cliniciens estiment que le temps réponse de trois semaines est long, ce qui risque de compromettre l'utilité clinique du suivi thérapeutique des anticrises. Un délai plus court prenant en considération le temps nécessaire pour acheminer l'échantillon au laboratoire devrait être visé. DIMENSION ÉCONOMIQUE: Efficience: Aucune étude évaluant l'efficience du suivi thérapeutique des anticrises de nouvelle génération par LC-MS/MS chez les patients atteints d'épilepsie n'a été repérée. Étant donné l'incertitude concernant les bénéfices de santé liés au suivi thérapeutique des anticrises de nouvelle génération par LC-MS/MS, l'INESSS ne peut pas évaluer l'efficience du panel proposé, par rapport aux dosages présentement effectués au Québec. L'analyse de coûts réalisée montre que son utilisation pourrait permettre une réduction des coûts de 12 $ à 103 $, par rapport aux analyses présentement au Répertoire. Analyse d'impact budgétaire: Vu l'incertitude entourant certains paramètres de l'analyse d'impact budgétaire, une approche par scénario a été privilégiée. Selon le scénario considéré, l'ajout du panel proposé pourrait engendrer des coûts de 55 k$ à 821 k$ au cours des trois premières années, pour la réalisation de 12 900 à 33 900 analyses. Ces résultats sont toutefois empreints d'incertitude, puisqu'il est difficile d'évaluer avec précision le nombre d'analyses anticipées. CONCLUSIONS: Afin de maximiser l'utilité clinique anticipée et de limiter le risque d'usage non optimal, l'INESSS préciseb que les conditions suivantes sont nécessaires à l'implantation de l'analyse proposée: Le temps réponse clinique devrait être au maximum de dix jours (incluant le temps requis pour acheminer l'échantillon au laboratoire). Il faudra assurer un suivi d'implantation du test au cours des prochaines années afin de documenter, notamment, les indications cliniques, les temps réponse, la volumétrie et les coûts d'analyse. Le formulaire de requête devrait permettre de sélectionner l'indication clinique pour laquelle le test est demandé, soit: - suspicion de toxicités; - crises épileptiques non contrôlées; - grossesse; - maladie hépatique ou rénale; - interactions médicamenteuses; - altération pharmacocinétique autre; - suspicion de non-observance thérapeutique; - pédiatrie. Les analyses réalisées par une trousse commerciale ou une méthode développée en laboratoire devraient satisfaire aux exigences de la norme ISO 15189. L'offre de service devrait être disponible dans plusieurs laboratoires à travers la province.

INTRODUCTION: The Centre hospitalier de l'Université de Montréal (CHUM) has submitted a request to introduce a new assay to the Répertoire québécois et système de mesure des procédures de biologie médicale (hereinafter referred to as the "Répertoire"), and has forwarded it to the Institut national d'excellence en santé et en services sociaux (INESSS) in accordance with the evaluation mechanism for new medical biology assays. The mandate given was to evaluate the new-generation anti-seizure panel assay by liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) as part of the therapeutic follow-up of epilepsy. As this assay is not listed in the Répertoire, the Ministère de la Santé et des Services sociaux (MSSS) considers it necessary to evaluate its relevance. METHODOLOGY: The evaluation approach included a review of the scientific literature, a search of the grey literature, and consultations with clinicians and other stakeholders. The methodology was structured around seven evaluation questions, covering socio-cultural, population, clinical (clinical validity and clinical utility), organizational and economic (efficacy and budgetary impact) dimensions. A review of the economic literature was conducted, along with a feasibility evaluation of economic modeling to measure the effectiveness of LC-MS/MS dosing of new-generation anti-seizure agents. A budgetary impact analysis was conducted, considering the costs associated with the introduction of new-generation LCMS/MS anti-seizure assays to the Repertoire. Costs were projected over a three-year time horizon from a healthcare system perspective. All scientific, contextual, and experiential data were interpreted and synthesized into findings to guide the deliberative process of the Standing Deliberative Committee (SDC) - Diagnostic Approaches and Screening, in order to develop recommendations. EVALUATION CONTEXT: Epilepsy has significant neurological, cognitive, psychological, and social consequences for sufferers. The treatment of epilepsy is essentially pharmacological. Depending on the individual, drugs may have varying degrees of efficacy, safety, and side effects. It is therefore essential to monitor the progression of this disease and adapt management accordingly. The use of anti-seizure monitoring is increasingly recommended. However, many other widely used anti-seizure drugs do not benefit from an officially listed dosing procedure in the Répertoire. To date, only two assays for the new-generation anti-seizure drugs lamotrigine (30690) and clobazam (30660) are listed in the Répertoire. SOCIOCULTURAL DIMENSION: The Government of Ontario's Clinical Practice Guidelines for the Management of Epilepsy, and similar documents from international learned societies, state that antiseizure therapy is based on the clinical judgment of the treating physician. Although it is not recommended to do so systematically for all patients, therapeutic follow-up should be considered when seizures are uncontrolled, when a condition altering pharmacokinetics such as pregnancy is present, or when toxicity or non-adherence is suspected. Population Dimension Epilepsy affects some 300,000 people in Canada and is diagnosed at all ages. Epilepsy increases the risk of injury and premature death, can disrupt sleep, affect career choices, limit physical activity, and restrict driving privileges. The stigma associated with epilepsy is a considerable challenge for some patients, impacting on their overall quality of life. Anti-seizure medication remains the mainstay of epilepsy treatment. They reduce the frequency of seizures while improving patients' quality of life. Effective plasma concentrations vary from one individual to another, and do not necessarily fall within a reference range. Identifying an individual plasma concentration may therefore be desirable. Anti-seizure medications have adverse effects that can interfere with daily life and must be considered in their management. In Quebec, the current supply of assays for therapeutic monitoring of new-generation anti-seizure drugs (TDM) does not meet clinicians' needs. In fact, many of these drugs are not assayed, and the response time to obtain assay results for those that are is deemed unacceptable. CLINICAL DIMENSION: Despite a generally low body of evidence, the selected studies indicated that administering new-generation anti-seizure drugs as part of follow-up therapy would offer some clinical benefits, such as better seizure control or fewer adverse effects. This could be particularly advantageous for patients with increased pharmacokinetic variability, such as children, the elderly, pregnant women, and patients with comorbidities. In light of the identified scientific literature and expert opinion, LC MS/MS is considered a reference method for assaying new-generation anti-seizures from serum or plasma samples. ORGANIZATIONAL DIMENSION. LC-MS/MS offers the possibility of analyzing a batch of samples from different patients treated with one or more anti-seizures, making it easier to centralize and optimize procedures. Some laboratories have the resources needed to assay new-generation anti-seizures using a multiplex LC-MS/MS approach. Clinicians consider the three-week response time to be long, which may compromise the clinical usefulness of anti-seiz follow-up therapy. A shorter response time, considering the time needed to get the sample to the laboratory, should be targeted. ECONOMIC DIMENSION: Effectiveness: No studies evaluating the cost-effectiveness of therapeutic monitoring of new-generation anti-seizure assays by LC-MS/MS in patients with epilepsy have been identified. Given the uncertainty surrounding the health benefits associated with therapeutic monitoring of new-generation anti-seizure assays by LC-MS/MS, the INESSS is unable to evaluate the effectiveness of the proposed panel, compared with the assays currently performed in Quebec. The cost analysis conducted shows that its use could result in a cost reduction of $12 to $103, compared with assays currently in the Répertoire. BUDGET IMPACT ANALYSIS: Given the uncertainty surrounding certain parameters of the budget impact analysis, a scenario-based approach was adopted. Depending on the scenario considered, the addition of the proposed panel could generate costs of between $55k and $821k over the first three years for the completion of between 12,900 and 33,900 assays. However, these results are subject to uncertainty, since it is difficult to accurately estimate the number of anticipated assays. CONCLUSIONS: In order to maximize anticipated clinical utility and limit the risk of sub-optimal use, the INESSS stipulates that the following conditions are necessary for the implementation of the proposed assay: Clinical response time should be a maximum of ten days (including the time required to transport the sample to the laboratory). Implementation of the assay will have to be monitored over the next few years, in order to document clinical indications, response times, volumetry, and analysis costs. The request form should make it possible to select the clinical indication for which the assay is requested, i.e., suspected toxicity; uncontrolled epileptic seizures; pregnancy; liver or kidney disease; drug interactions; other pharmacokinetic alterations; suspected non-compliance; pediatrics. Assays conducted using either a commercial kit or a laboratory-developed method should meet ISO 15189 requirements. The service should be available in several laboratories across the province.

Use of micro, capillary, and nano liquid chromatography for forensic analysis.

The use of micro, capillary, and nano liquid chromatography systems for forensic analysis has excellent potential. In a field where sample size is often limited, several studies have presented the viability of capillary columns with microflow and nanoflow, and when using mass spectrometric analysis limits of detection can be improved. Reduction in flow rates result in significant reduction in operating costs. Recent advances in miniaturized liquid chromatography systems also aim at in-laboratory and on-site detection, which have already been applied to forensic drug cases. This critical review will discuss the advantages, disadvantages, and applicability of microflow and nano liquid chromatography. In this regard, included in this article is a discussion of some promising areas not yet applied to forensic research.

Using 1.5 mm internal diameter columns for optimal compatibility with current liquid chromatographic systems.

This article describes the use of a new prototype column hardware made with 1.5 mm internal diameter (i.d.) and demonstrates some benefits over the 1.0 mm i.d. micro-bore column. The performance of 2.1, 1.5 and 1.0 mm i.d. columns were systematically compared. With the 1.5 mm i.d. column, the loss of apparent column efficiency can be significantly reduced compared to 1.0 mm i.d. columns in both isocratic and gradient elution modes. In the end, the 1.5 mm i.d. column is almost comparable to 2.1 mm i.d. column from a peak broadening point of view. The advantages of the 1.5 mm i.d. hardware vs 2.1 mm i.d. narrow-bore columns are the lower sample and solvent consumption, and reduced frictional heating effects due to decreased operating flow rates.

Cost-Effective Automated Preparation of Serum Samples for Reproducible Quantitative Clinical Proteomics.

Reproducible sample preparation remains a significant challenge in large-scale clinical research using selected reaction monitoring-mass spectrometry (SRM-MS), which enables a highly sensitive multiplexed assay. Although automated liquid-handling platforms have tremendous potential for addressing this issue, the high cost of their consumables is a drawback that renders routine operation expensive. Here we evaluated the performance of a liquid-handling platform in preparing serum samples compared with a standard experiment while reducing the outlay for consumables, such as tips, wasted reagents, and reagent stock plates. A total of 26 multiplex assays were quantified by SRM-MS using four sets of 24 pooled human serum aliquots; the four sets used a fixed number (1, 4, 8, or 24) of tips to dispense digestion reagents. This study demonstrated that the use of 4 or 8 tips is comparable to 24 tips (standard experiment), as evidenced by their coefficients of variation: 13.5% (for 4 and 8 tips) versus 12.0% (24 tips). Thus we can save 37% of the total experimental cost compared with the standard experiment, maintaining nearly equivalent reproducibility. The routine operation of cost-effective liquid-handling platforms can enable researchers to process large-scale samples with high throughput, adding credibility to their findings by minimizing human error.

Large-Scale Assessment of Extractables and Leachables in Single-Use Bags for Biomanufacturing.

Single-use technologies (SUTs) are widely used during biopharmaceutical manufacture as disposable bioreactors or media and buffer storage bags. Despite their advantages, the risk of release of extractable and leachable (E&Ls) substances is considered an important drawback in adopting disposables in the biomanufacturing process. E&Ls may detrimentally affect cell viability or productivity or may persist during purification and present a risk to the patient if remaining in the final drug product. In this study, 34 plastic films from single-use bags (SUBs) for cell cultivation were extracted with selected solvents that represent reasonable worst-case conditions for most typical biomanufacturing applications. SUBs were incubated at small-scale under accelerated-aging conditions that represented standard operational conditions of use. Leachables analysis was performed following dispersive liquid-liquid microextraction (DLLME) for analyte preconcentration and removal of matrix interference. Resulting extracts were characterized by GC-headspace for volatiles, high resolution GC-Orbitrap-MS/MS for semivolatiles, high resolution LC-Orbitrap-MS/MS for nonvolatiles, and ICP-MS for trace elemental analysis. Multivariate statistical analysis of the analytical data revealed significant correlations between the type and concentration of compounds and bags features including brand, manufacturing date and polymer type. The analytical data demonstrates that, over recent years, the nature of E&Ls has been altered due to the implementation of manufacturing changes and new types of polymers and may change further with the future advent of regulations that will limit or ban the use of certain raw materials and additives. The broad E&L database generated herein facilitates toxicological assessments from a biomanufacturing standpoint and provides practical guidelines for confident determination of E&Ls to enable screening and elimination of nonsatisfactory films for single use bioprocessing.

Sensitive, High-Throughput, and Robust Trapping-Micro-LC-MS Strategy for the Quantification of Biomarkers and Antibody Biotherapeutics.

For LC-MS-based targeted quantification of biotherapeutics and biomarkers in clinical and pharmaceutical environments, high sensitivity, high throughput, and excellent robustness are all essential but remain challenging. For example, though nano-LC-MS has been employed to enhance analytical sensitivity, it falls short because of its low loading capacity, poor throughput, and low operational robustness. Furthermore, high chemical noise in protein bioanalysis typically limits the sensitivity. Here we describe a novel trapping-micro-LC-MS (T-µLC-MS) strategy for targeted protein bioanalysis, which achieves high sensitivity with exceptional robustness and high throughput. A rapid, high-capacity trapping of biological samples is followed by µLC-MS analysis; dynamic sample trapping and cleanup are performed using pH, column chemistry, and fluid mechanics separate from the µLC-MS analysis, enabling orthogonality, which contributes to the reduction of chemical noise and thus results in improved sensitivity. Typically, the selective-trapping and -delivery approach strategically removes >85% of the matrix peptides and detrimental components, markedly enhancing sensitivity, throughput, and operational robustness, and narrow-window-isolation selected-reaction monitoring further improves the signal-to-noise ratio. In addition, unique LC-hardware setups and flow approaches eliminate gradient shock and achieve effective peak compression, enabling highly sensitive analyses of plasma or tissue samples without band broadening. In this study, the quantification of 10 biotherapeutics and biomarkers in plasma and tissues was employed for method development. As observed, a significant sensitivity gain (up to 25-fold) compared with that of conventional LC-MS was achieved, although the average run time was only 8 min/sample. No appreciable peak deterioration or loss of sensitivity was observed after >1500 injections of tissue and plasma samples. The developed method enabled, for the first time, ultrasensitive LC-MS quantification of low levels of a monoclonal antibody and antigen in a tumor and cardiac troponin I in plasma after brief cardiac ischemia. This strategy is valuable when highly sensitive protein quantification in large sample sets is required, as is often the case in typical biomarker validation and pharmaceutical investigations of antibody therapeutics.

Enhanced fluidity liquid chromatography of inulin fructans using ternary solvent strength and selectivity gradients.

The value of exploring selectivity and solvent strength ternary gradients in enhanced fluidity liquid chromatography (EFLC) is demonstrated for the separation of inulin-type fructans from chicory. Commercial binary pump systems for supercritical fluid chromatography only allow for the implementation of ternary solvent strength gradients which can be restrictive for the separation of polar polymeric analytes. In this work, a custom system was designed to extend the capability of EFLC to allow tuning of selectivity or solvent strength in ternary gradients. Gradient profiles were evaluated using the Berridge function (RF1), normalized resolution product (NRP), and gradient peak capacity (Pc). Selectivity gradients provided the separation of more analytes over time. The RF1 function showed favor to selectivity gradients with comparable Pc to that of solvent strength gradients. NRP did not strongly correlate with Pc or RF1 score. EFLC with the hydrophilic interaction chromatography, HILIC, separation mode was successfully employed to separate up to 47 fructan analytes in less than 25 min using a selectivity gradient.

Guideline values and human risk assessment for the presence of anti-inflammatory drugs remaining in drinking water after lab scale treatment

This study aimed to determine whether the anti-inflammatory drugs that are most commonly consumed in Brazil, including diclofenac, ketoprofen, naproxen, indomethacin, ibuprofen and acetaminophen, are present in drinking water and to derive guideline values to characterize the human risk. These pharmaceuticals were quantified in surface waters by LC-MS/MS with solid phase extraction, both before and after conventional treatment on a laboratory scale, using a jar test assay. The methods used to quantify these drugs showed good results: the chromatographic analysis obtained correlation coefficients between 0.9952 and 0.9991, with limits of quantification of 0.5 ng.mL-1 - 50 ng.mL-1 and precision standard deviations (0.08 - 2.08). Only ketoprofen and ibuprofen were not completely removed through the jar test. Environmental samples were collected and handled by the same method; the values |for ketoprofen and ibuprofen after treatment were 18.67 - 19.65 ng.L-1 (±17%) and 166.70 - 244.73 ng.L-1 (±14%), respectively. Human risk was assessed by comparing the guideline values for each compound to the concentrations obtained in the environmental samples, considering the toxicological backgrounds, following WHO (2011) method. The results suggest that the concentrations of ketoprofen and ibuprofen found in drinking water do not pose a risk to human health, even with chronic consumption

Yield of 6,000 proteins by 1D nLC-MS/MS without pre-fractionation.

Mass spectrometry (MS) has dominated over other protein analysis methods that aspire to deliver rapid and sensitive protein annotation, due to its ability to acquire high-content biological information from samples of great complexity. Routinely, in-depth analysis of complex biological samples, such as total cell lysates, relies on the high separation power of two-dimensional liquid chromatography-tandem MS (2D LC-MS/MS), often combined with protein pre-fractionation. However, on the basis of recent advances in chromatographic and MS instrumentation, one-dimensional (1D) LC-MS/MS approaches have become the method-of-choice for high-volume/high-throughput protein experiments. Thousands of proteins can be identified in single-run LC-MS/MS experiments. In the present study a 1D LC-MS/MS approach was applied on whole-cell lysates of WM-266-4 human cells leading to identification of more than 5,300 protein groups, 6,000 proteins and 22,00 peptides, in a single run. Using no pre-fractionation steps, method optimization was achieved through experimentation on lysis and protein extraction solutions, as well as nLC gradient parameters.

Quick, easy, cheap, effective, rugged, and safe sample preparation approach for pesticide residue analysis using traditional detectors in chromatography: A review.

In pesticide residue analysis, relatively low-sensitivity traditional detectors, such as UV, diode array, electron-capture, flame photometric, and nitrogen-phosphorus detectors, have been used following classical sample preparation (liquid-liquid extraction and open glass column cleanup); however, the extraction method is laborious, time-consuming, and requires large volumes of toxic organic solvents. A quick, easy, cheap, effective, rugged, and safe method was introduced in 2003 and coupled with selective and sensitive mass detectors to overcome the aforementioned drawbacks. Compared to traditional detectors, mass spectrometers are still far more expensive and not available in most modestly equipped laboratories, owing to maintenance and cost-related issues. Even available, traditional detectors are still being used for analysis of residues in agricultural commodities. It is widely known that the quick, easy, cheap, effective, rugged, and safe method is incompatible with conventional detectors owing to matrix complexity and low sensitivity. Therefore, modifications using column/cartridge-based solid-phase extraction instead of dispersive solid-phase extraction for cleanup have been applied in most cases to compensate and enable the adaptation of the extraction method to conventional detectors. In gas chromatography, the matrix enhancement effect of some analytes has been observed, which lowers the limit of detection and, therefore, enables gas chromatography to be compatible with the quick, easy, cheap, effective, rugged, and safe extraction method. For liquid chromatography with a UV detector, a combination of column/cartridge-based solid-phase extraction and dispersive solid-phase extraction was found to reduce the matrix interference and increase the sensitivity. A suitable double-layer column/cartridge-based solid-phase extraction might be the perfect solution, instead of a time-consuming combination of column/cartridge-based solid-phase extraction and dispersive solid-phase extraction. Therefore, replacing dispersive solid-phase extraction with column/cartridge-based solid-phase extraction in the cleanup step can make the quick, easy, cheap, effective, rugged, and safe extraction method compatible with traditional detectors for more sensitive, effective, and green analysis.

An alternative approach for assessment of liquid chromatography-mass spectrometry matrix effects using auto-sampler programmed co-injection.

We report the use of auto-sampler programmable functions to co-inject analyte standard solution and matrix extract to assess ion enhancement and suppression (matrix effects) in LC-MS. This is effectively an automated post-extraction addition (APEA) procedure, emulating the manual post-extraction addition (PEA) approach widely adopted for assessment of matrix effects. To verify that APEA was comparable to the conventional PEA approach, matrix effects were determined using both methods for a selection of 31 illicit and pharmaceutical drugs in 10 different human urine extracts. Matrix effects measured using APEA were statistically indistinguishable from manual PEA methodology for 27 of the 31 drugs. Of the four drugs that showed significant differences using the two methods, three differed by less than 2 %, which is within the expected accuracy limits required for matrix effect determinations. The remaining analyte, trimeprazine, was found to degrade in the spiked PEA matrix extract, accounting for the difference between matrix effects measured by the PEA and APEA approaches. APEA enables a single matrix extract to be assessed at multiple analyte concentrations, resulting in a considerable reduction in sample preparation time. In addition, APEA can reduce the quantity of analyte-free sample matrix required for matrix effect assessment, which is an important consideration in certain analytical and bioanalytical fields. This work shows that APEA may be considered as an acceptable alternative to PEA for the assessment of matrix effects in LC-MS method validation and may be applicable to a variety of matrices such as environmental samples.

Rapid determination of 12 antibiotics and caffeine in sewage and bioreactor effluent by online column-switching liquid chromatography/tandem mass spectrometry.

This study presents a column-switching solid-phase extraction online-coupled to a liquid chromatography/tandem mass spectrometry (SPE-LC-MS/MS) method for simultaneous analysis of 12 antibiotics (7 sulfonamides and 5 fluoroquinolones) and caffeine detected in the sewage and effluent of a pilot anaerobic reactor used in sewage treatment. After acidification and filtration, the samples were directly injected into a simple and conventional LC system. Backflush and foreflush modes were compared based on the theoretical plates and peak asymmetry observed. The method was tested in terms of detection (MDL) and quantification limit (MQL), linearity, relative recovery, and precision intra- and inter-day in lab-made sewage samples. The method presented suitable figures of merit in terms of detection, varying from 8.00 × 10(-5) to 6.00 × 10(-2) ng (0.800 up to 600 ng L(-1); caffeine) with direct injection volume of only 100 µL and 13 min of total analysis time (sample preparation and chromatographic run). When the method was applied in the analysis of sewage and effluent of the anaerobic reactor (n = 15), six antibiotics and caffeine were detected in concentrations ranging from 0.018 to 1097 µg L(-1). To guarantee a reliable quantification, standard addition was used to overcome the matrix effect.

Robust high-throughput batch screening method in 384-well format with optical in-line resin quantification.

High-throughput batch screening technologies have become an important tool in downstream process development. Although continuative miniaturization saves time and sample consumption, there is yet no screening process described in the 384-well microplate format. Several processes are established in the 96-well dimension to investigate protein-adsorbent interactions, utilizing between 6.8 and 50 µL resin per well. However, as sample consumption scales with resin volumes and throughput scales with experiments per microplate, they are limited in costs and saved time. In this work, a new method for in-well resin quantification by optical means, applicable in the 384-well format, and resin volumes as small as 0.1 µL is introduced. A HTS batch isotherm process is described, utilizing this new method in combination with optical sample volume quantification for screening of isotherm parameters in 384-well microplates. Results are qualified by confidence bounds determined by bootstrap analysis and a comprehensive Monte Carlo study of error propagation. This new approach opens the door to a variety of screening processes in the 384-well format on HTS stations, higher quality screening data and an increase in throughput.

The second five years of sequential injection chromatography: significant developments in the technology and methodologies.

Sequential injection chromatography was proposed in 2003 to perform a simple, rapid, reagent-saving, environmentally benign, on-site, and instrumentally inexpensive separation procedure. Sequential injection chromatography is a version of sequential injection analysis, which is the second generation in the family of flow injection techniques. Despite its advantages over high-performance liquid chromatography, sequential injection chromatography has confronted some challenges. Furthermore, the applications of sequential injection chromatography in its first five years are almost all limited to pharmaceutical analysis. Interestingly, in its second five years, various developments in sequential injection chromatography technology were achieved. The developments have enhanced the efficiency of sequential injection chromatography and hence its applications have extended to biological, food, and environmental analyses. The main objectives of this review are to examine recent developments (2008-2013) in sequential injection chromatography and to describe how these developments improve the efficiency of the technology. The sequential injection chromatography methodologies reported during that period are also discussed along with controlling conditions and analytical results. The review also describes the principles, instrumentation, and procedure behind sequential injection chromatography.

Retention mechanism assessment and method development for the analysis of iohexol and its related compounds in hydrophilic interaction liquid chromatography.

Hydrophilic interaction liquid chromatography (HILIC) has emerged in recent years as a valuable alternative to reversed-phase liquid chromatography in the analysis of polar compounds. Research in HILIC is divided into two directions: the assessment of the retention mechanism and retention behavior, and the development of HILIC methods. In this work, four polar neutral analytes (iohexol and its related compounds A, B, and C) were analyzed on two silica and two diol columns in HILIC mode with the aim to investigate thoroughly the retention mechanisms and retention behavior of polar neutral compounds on these four columns. The adsorption and partition contribution to the overall HILIC retention mechanism was investigated by fitting the retention data to linear (adsorption and partition) and nonlinear (mixed-retention and quadratic) theoretical models. On the other hand, the establishment of empirical second-order polynomial retention models on the basis of D-optimal design made possible the estimation of the simultaneous influence of several mobile-phase-related factors. Furthermore, these models were also used as the basis for the application of indirect modeling of the selectivity factor and a grid point search approach in order to achieve the optimal separation of analytes. After the optimization goals had been set, the grids were searched and the optimal conditions were identified. Finally, the optimized method was subjected to validation.

Design, implementation and multisite evaluation of a system suitability protocol for the quantitative assessment of instrument performance in liquid chromatography-multiple reaction monitoring-MS (LC-MRM-MS).

Multiple reaction monitoring (MRM) mass spectrometry coupled with stable isotope dilution (SID) and liquid chromatography (LC) is increasingly used in biological and clinical studies for precise and reproducible quantification of peptides and proteins in complex sample matrices. Robust LC-SID-MRM-MS-based assays that can be replicated across laboratories and ultimately in clinical laboratory settings require standardized protocols to demonstrate that the analysis platforms are performing adequately. We developed a system suitability protocol (SSP), which employs a predigested mixture of six proteins, to facilitate performance evaluation of LC-SID-MRM-MS instrument platforms, configured with nanoflow-LC systems interfaced to triple quadrupole mass spectrometers. The SSP was designed for use with low multiplex analyses as well as high multiplex approaches when software-driven scheduling of data acquisition is required. Performance was assessed by monitoring of a range of chromatographic and mass spectrometric metrics including peak width, chromatographic resolution, peak capacity, and the variability in peak area and analyte retention time (RT) stability. The SSP, which was evaluated in 11 laboratories on a total of 15 different instruments, enabled early diagnoses of LC and MS anomalies that indicated suboptimal LC-MRM-MS performance. The observed range in variation of each of the metrics scrutinized serves to define the criteria for optimized LC-SID-MRM-MS platforms for routine use, with pass/fail criteria for system suitability performance measures defined as peak area coefficient of variation <0.15, peak width coefficient of variation <0.15, standard deviation of RT <0.15 min (9 s), and the RT drift <0.5min (30 s). The deleterious effect of a marginally performing LC-SID-MRM-MS system on the limit of quantification (LOQ) in targeted quantitative assays illustrates the use and need for a SSP to establish robust and reliable system performance. Use of a SSP helps to ensure that analyte quantification measurements can be replicated with good precision within and across multiple laboratories and should facilitate more widespread use of MRM-MS technology by the basic biomedical and clinical laboratory research communities.

A simplified and completely automated workflow for regulated LC-MS/MS bioanalysis using cap-piercing direct sampling and evaporation-free solid phase extraction.

Automated sample extraction for regulated bioanalysis by liquid chromatography/tandem mass spectrometry (LC-MS/MS) still presents significant challenges. A new sample preparation methodology with a simplified and completely automated workflow was developed to overcome these challenges using cap piercing for direct biofluid transfer and evaporation-free solid phase extraction (SPE). Using pierceable cap sample tubes, a robotic liquid handler was able to sample without uncapping or recapping during sample preparation. Evaporation for SPE was eliminated by using a mobile phase-compatible elution solvent followed by sample dilution prior to LC-MS/MS analysis. Presented here are three LC-MS/MS assays validated using this methodology to support three CNS drug development programs: (1) BMS-763534 and its metabolite, BMS-790318, in dog plasma; (2) BMS-694153 in monkey plasma; and (3) Pexacerfont (BMS-562086) and two metabolites, BMS-749241 and DPH-123554, in human plasma. These assays were linear from 1.00 to 1000 or 2.00 to 2000ng/mL for each analyte with excellent assay accuracy, precision and reproducibility. These assays met acceptance criteria for regulated bioanalysis and have been successfully applied to drug development study samples. The methodology described here successfully eliminated all manual intervention steps achieving fully automated sample preparation without compromising assay performance. Importantly, this methodology eliminates the potential exposure of the bioanalyst to any infectious biofluids during sample preparation.

Challenges in the development of bioanalytical liquid chromatography-mass spectrometry method with emphasis on fast analysis.

The development of bioanalytical methods has become more and more challenging over the past years due to very demanding requirements in terms of method reliability, sensitivity, speed of analysis and sample throughput. LC-MS/MS has established itself as a method of choice for routine analysis of biological materials. A development of such method consists of several steps including sample preparation and clean-up step, efficient chromatographic separation, sensitive and selective detection of analytes in complex matrices, a choice of convenient data processing and calibration approach and finally method validation. Each of these steps has its own constraints and challenges, which are discussed in detail in this review. Novel and modern approaches in sample preparation, chromatography and detection are especially emphasized. Attention is paid to proper calibration approach and matrix effects that can seriously affect method accuracy and precision.