Modern Analytical Laboratory Research Articles

A Review of Liquid Chromatography-Mass Spectrometry and its Applications in Chemical Analysis

Liquid Chromatography-Mass Spectrometry (LC-MS) has emerged as a powerful analytical technique combining the separation capabilities of liquid chromatography with the high sensitivity and selectivity of mass spectrometry. This sophisticated instrumentation enables precise identification and quantification of complex chemical mixtures across diverse fields including pharmaceuticals, environmental monitoring, food safety, and biological research. Modern LC-MS systems offer enhanced resolution, improved ionization methods, and sophisticated mass analyzers that facilitate accurate molecular weight determination and structural elucidation of compounds. Recent technological advancements have led to the development of ultra-high-performance liquid chromatography (UHPLC) systems coupled with high-resolution mass spectrometers, enabling faster analysis times and improved detection limits. The versatility of LC-MS is demonstrated through its applications in proteomics, metabolomics, drug development, and quality control processes. Integration of artificial intelligence and machine learning algorithms has further enhanced data processing capabilities, allowing for automated peak identification and complex mixture analysis. The continuous evolution of LC-MS technology has addressed previous limitations in ionization efficiency, matrix effects, and quantification accuracy. This analytical technique has revolutionized chemical analysis by providing comprehensive molecular information, making it an indispensable tool in modern analytical laboratories.

John Hollerton: a life in industrial analytical spectroscopy, part 2

This is the second part of an interview with John Hollerton, the first part in is the last issue! John recently retired from a long career at GSK and we took this opportunity to have a chat with him, as Mohan Cashyap and our beloved editor Ian Michael both have had the opportunity to work with John on projects and on the LISMS conference (Linking and Interpreting Spectra through Molecular Structures). Here, we move the discussion on to technologies and innovation, the great, the over-hyped and the effectively lost to the modern analytical laboratory.

Food analysis: a practical guide

Food analysis: a practical guide

Gravimetric titrations in a modern analytical laboratory: evaluation of performance and practicality in everyday use

Gravimetric titrations in a modern analytical laboratory: evaluation of performance and practicality in everyday use

Residual analysis of selected pesticides in cucumber and spinach collected from local markets of Mymensingh sadar

To explore the chemical contamination of vegetables available in local market of Mymensingh this research work undertaken for detection and quantification of the presence of pesticides. Standard pesticides and GC (Gas Chromatography) were used to confirm their retention times and area of eluted peaks. By comparing the retention times of standards and samples, confirmation of residual presence of pesticides were studied. A result revealed that residue of a fungicide (Common Name: Mancozeb, a.i: Symoxanil 72 wp) was found in one Cucumber sample out of three where 50 ppm quantified. On the other hand, out of 3 spinach samples, 1 of them showed presence of a insecticide (Common name: imidachloropid; a.i.: imidachloropid 20 SL) residues, which quantified as 35 ppm. Residual quantity determined in cucumber sample of BAUSesh More and spinach sample of Kewatkhali market, Mymensingh. To clarify the existing scenario in respect of all pesticide residues in vegetable sample, it would be necessary to develop all facilities for a modern analytical laboratories and skilled manpower. It may be useful for creating awareness about the available vegetables in consumers and farmers community.Progressive Agriculture 26:38-44, 2015

Defining the challenges of the Modern Analytical Laboratory (CPSA USA 2014): the risks and reality of personalized healthcare.

The 17th Annual Symposium on Clinical and Pharmaceutical Solutions through Analysis (CPSA) 29 September-2 October 2014, was held at the Sheraton Bucks County Hotel, Langhorne, PA, USA. The CPSA USA 2014 brought the various analytical fields defining the challenges of the modern analytical laboratory. Ongoing discussions focused on the future application of bioanalysis and other disciplines to support investigational new drugs (INDs) and new drug application (NDA) submissions, clinical diagnostics and pathology laboratory personnel that support patient sample analysis, and the clinical researchers that provide insights into new biomarkers within the context of the modern laboratory and personalized medicine.

Capillary electrophoresis in an extended nanospray tip–electrospray as an electrophoretic column

Capillary electrophoresis coupled to mass spectrometry (CE/MS) is gaining its space among the most powerful tools in modern (bio)analytical laboratory. The most challenging instrumental aspect in CE/MS is striking the balance between the stability and reproducibility of the signal and sensitivity of the analysis. Several interface designs have been published in the past decade addressing the variety of instrumental aspects and ease of operation. Most of the interfaces can be categorized either into the sheath flow arrangement (considered to be a de facto standard), or sheathless interface, often expected to provide the ultimate sensitivity. In this work we have explored an “interface-free” approach, where the CE/MS analysis was performed in narrow bore (<20μm ID) electrospray capillary. The separation capillary and electrospray tip formed one entity and the high voltage, applied at the injection end of the capillary served for both the separation and electrospray ionization. Thus the separation voltage was defined as the product of the electrospray current and resistivity of the separation electrolyte. Optimum conditions for the separation and electrospray ionization were achieved with voltage programming. The performance of this simplest possible CE/MS system was tested on peptide separations from the cytochrome c tryptic digest. The subnanoliter sample consumption and sensitivity in the attomole range predetermines such a system for analysis of limited samples.

Improving characterization of monoclonal antibodies: Making a better biotherapeutic

Characterization of therapeutic proteins remains labor-intensive and time consuming due to their often complex and heterogeneous structure. This has led to a concerted effort within the biotechnology and biopharmaceutical industry to address these bottlenecks as a means to boost the development of more biotherapeutics. Studies in this vein, such as testing the effect of various cell culture conditions on posttranslational modifications or monitoring the purification process of recombinant proteins, produce large numbers of samples that can easily exceed the capacity of modern analytical laboratories. High throughput analytical platforms with high precision, automation, and ease-of-use are therefore in great demand. To this end, the use of microfluidic analytical platforms such as microchip capillary electrophoresis (CE) have greatly increased the efficiency and reproducibility needed for analyzing proteins intended for therapeutic use. In this webinar, our expert panelists will discuss posttranslational modifications and quality assessment of biotherapeutic proteins for biopharmaceutical development using microfluidic-CE characterization. View the Webinar

Application of fast Fourier transform cross-correlation and mass spectrometry data for accurate alignment of chromatograms

Chromatography has been established as one of the most important analytical methods in the modern analytical laboratory. However, preprocessing of the chromatograms, especially peak alignment, is usually a time-consuming task prior to extracting useful information from the datasets because of the small unavoidable differences in the experimental conditions caused by minor changes and drift. Most of the alignment algorithms are performed on reduced datasets using only the detected peaks in the chromatograms, which means a loss of data and introduces the problem of extraction of peak data from the chromatographic profiles. These disadvantages can be overcome by using the full chromatographic information that is generated from hyphenated chromatographic instruments. A new alignment algorithm called CAMS (Chromatogram Alignment via Mass Spectra) is present here to correct the retention time shifts among chromatograms accurately and rapidly. In this report, peaks of each chromatogram were detected based on Continuous Wavelet Transform (CWT) with Haar wavelet and were aligned against the reference chromatogram via the correlation of mass spectra. The aligning procedure was accelerated by Fast Fourier Transform cross correlation (FFT cross correlation). This approach has been compared with several well-known alignment methods on real chromatographic datasets, which demonstrates that CAMS can preserve the shape of peaks and achieve a high quality alignment result. Furthermore, the CAMS method was implemented in the Matlab language and available as an open source package at http://www.github.com/matchcoder/CAMS.

The comet disintegration and meteor streams

Possibility of disintegration of proto-comet nucleus of sungraser comets in three zones of Solar System predicted by one of authors is considered. Testing of parameters of 118 split comets confirms the basic idea. Results of the statistical analysis of comet outbursts gave us additional argument in favor of this assumption. Almost twenty years have passed since, as a result of the search for host phases of isotopically unusual noble gases, the first discovery in 1987 of surviving pre-solar minerals (diamond and silicon carbide) in primitive meteorites. These were followed by others (graphite, refractory oxides, silicon nitride, and finally silicates) in the years since. Pre-solar grains occur in even higher abundance than in meteorites in interplanetary dust particles (IDPs). The result is a kind of ‘new astronomy’ based on the study of pre-solar condensates with all the methods available in modern analytical laboratories.

Chemometrics in Pharmaceutical Analysis: An Introduction, Review, and Future Perspectives

Chemometrics is the application of statistical and mathematical methods to analytical data to permit maximum collection and extraction of useful information. The utility of chemometric techniques as tools enabling multidimensional calibration of selected spectroscopic, electrochemical, and chromatographic methods is demonstrated. Application of this approach mainly for interpretation of UV-Vis and near-IR (NIR) spectra, as well as for data obtained by other instrumental methods, makes identification and quantitative analysis of active substances in complex mixtures possible, especially in the analysis of pharmaceutical preparations present in the market. Such analytical work is carried out by the use of advanced chemical instruments and data processing, which has led to a need for advanced methods to design experiments, calibrate instruments, and analyze the resulting data. The purpose of this review is to describe various chemometric methods in combination with UV-Vis spectrophotometry, NIR spectroscopy, fluorescence spectroscopy, electroanalysis, chromatographic separation, and flow-injection analysis for the analysis of drugs in pharmaceutical preparations. Theoretical and practical aspects are described with pharmaceutical examples of chemometric applications. This review will concentrate on gaining an understanding of how chemometrics can be useful in the modern analytical laboratory. A selection of the most challenging problems faced in pharmaceutical analysis is presented, the potential for chemometrics is considered, and some consequent implications for utilization are discussed. The reader can refer to the citations wherever appropriate.

Computer-assisted modelling and optimisation of reversed-phase high-temperature liquid chromatographic (RP-HTLC) separations

The use of high temperatures (above 100 °C) in reversed-phase liquid chromatography (RP-HTLC) has opened up novel and enhanced applications for this essential separation technique. Although the favourable effects of temperature on LC have been extensively studied both theoretically and practically, its potential application to method development has barely been investigated. These favourable effects include enhanced speed, efficiency, resolution and detectability, as well as changes in selectivity, especially for polar and ionisable compounds, and the emergence of new options such as temperature programming and the concomitant use of solvent and temperature gradients, green separations, and so on. The recent availability of silica-based columns that routinely support high temperatures in addition to more conventional temperature-resistant columns (based on graphitised carbon, polymers and zirconium oxide) and dedicated column ovens that allow accurate temperature control up to 200 °C makes it possible to conceive of RP-HTLC as a routine separation technique in the modern analytical laboratory. On the other hand, the addition of temperature as a new optimisable parameter to RPLC adds further complexity to method development. Thus, new computer-assisted optimisation tools that extend the capabilities of current computer-assisted tools are being specifically developed for this type of separation. A new specially developed computer-assisted method development (CAMD) tool is presented herein, and its efficiency is demonstrated. This CAMD is based on the development of a rugged retention model for peaks, allowing the simulation of any kind of RP-HTLC separation, including isocratic, linear, curved, multilinear and stepwise gradients of solvent composition concomitant with constant, linear and multilinear temperature gradients. Both the retention models and the unattended optimisation of separations are driven by evolutionary algorithms, thus providing negligible-cost, rapid, highly efficient, and user-friendly optimisation processes.

Artifactual formylation of the secondary amine of duloxetine hydrochloride by acetonitrile in the presence of titanium dioxide: Implications for HPLC method development

Duloxetine hydrochloride, a secondary amine containing pharmaceutical, currently marketed as Cymbalta™, is shown to undergo N-formylation as an artifact of sample preparation prior to HPLC analysis for impurities. The reaction was discovered as a result of an investigation into variability in the levels of N-formyl duloxetine observed upon HPLC analysis. The reaction is catalyzed by sonication and/or light in the presence of titanium dioxide and is proposed to occur via a radical-initiated mechanism. The mechanism is supported by controlled sample preparation studies with deuterium-labeled acetonitrile and LC/MS studies that showed incorporation of one deuterium into N-formyl duloxetine. This discovery is broadly relevant because sonication is commonly used to aid dissolution of pharmaceuticals in acetonitrile for HPLC analysis, titanium dioxide is a commonly used excipient, the amount of light found in modern analytical laboratories is sufficient to cause the reaction to occur, and secondary amines are present in the structures of many pharmaceuticals. The artifactual reaction was effectively eliminated by changing the sample solvent to methanol and replacing sonication with shaking to aid sample dissolution.

Three‐way comparison of methods for the measurement of the erythrocyte sedimentation rate

An erythrocyte sedimentation rate (ESR) is a nonspecific sickness index, which is not diagnostic of any particular disease, but which when elevated may indicate the presence of inflammation, infection, rheumatologic disease, or neoplasm. Technological advances continue to evolve to make this old test to conform to requirements of a modern analytical laboratory. In this evaluation, two new semi-automated ESR measuring systems, the HumaSed and ESR-Auto Plus (EAP), were compared with the Westergren method with regard to the accuracy and precision of ESR measurement, sample stability, and interference of various substances with the ESR assay. Samples from 125 patients were analyzed with the three methods and the results compared using linear regression and Bland-Altman plots. The mean ESR values of the HumaSed (32.10+/-4.86) and EAP (38.09+/-5.33) were comparable to that of the Westergren (31.54+/-4.94). The high correlation coefficients of 0.910-0.96 and the Bland-Altman scatter plots revealed good association and agreement between the three methods. Bias between the three methods was small and the imprecision was within acceptable limits. ESR analysis beyond 4 hr was found to be unacceptable owing to sample instability. There was bilirubin and lipid but not heparin interference in the two automated systems. Overall, two automated analyzers were found to be fast, reliable, standardized, simplified, and safe instruments with accuracy and precision for ESR measurement comparable to the Westergren.

A Set Up of a Modern Analytical Laboratory for Wastewaters from Pulp and Paper Industry

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Multivariate Curve Resolution Methods Illustrated Using Infrared Spectra of an Alcohol Dissolved in Carbon Tetrachloride

Methods of curve resolution are new tools to meet the demands of effective data analysis in the modern analytical laboratory. Here, we present one way of resolving a data set typical for the chemical laboratory. To illustrate the necessary steps in a successful curve resolution, infrared spectra of an increasing concentration of 1-octanol in carbon tetrachloride are used. The IR spectra change dramatically as the alcohol self-associates and form various types of hydrogen-bonded aggregates. We present a model containing three different alcohol species. The species represent free alcohol monomers, open-chain oligomers, and cyclic oligomers. The number of non- and hydrogen-bonded species giving a unique contribution to the spectral variance is found using chemical rank analysis. The rank analysis is performed on the complete data matrix, as well as on the most interesting regions of the data. This enables the decomposition of the data matrix into spectral and concentration profiles for each species present. The resolution was performed using eigenstructure tracking analysis followed by alternating least squares.

A set up of a modern analytical laboratory for wastewaters from pulp and paper industry

The introduction of analytical techniques allowing rapid, selective, sensitive, and reliable determination of aqueous pollutants is of crucial importance for the protection of the environment. This critical review summarizes the advanced analytical techniques suggested over the last ten years together with already established methods, and evaluates whether they are fit for wastewater quality assessment considering the area of application, interferences, limit of detection, calibration function, and precision. The key parameters of wastewater quality assessment are: total organic carbon (TOC), chemical oxygen demand (COD), biochemical oxygen demand (BOD), organochlorines (AOX), nitrogen, phosphorus, sulfur, and toxicity. Chromatography and capillary electrophoresis, photocatalytic oxidation with semiconductor nanofilms and atomic emission spectrometry, optical fibre sensors and chemiluminescence, amperometric mediated biosensors and microbial fuel cells, respirometry and bioluminescence measurements are just part of the proposed wastewater analyst's toolkit. The diversity of fundamental phenomena and the captivating elegance of interdisciplinary applications involved in the development of wastewater analytical techniques should attract the interest of a wide scientific audience including analytical chemists, chemical physicists, microbiologists and environmentalists. To conclude, we suggest a laboratory set up for the analysis of wastewaters from the pulp and paper industry.

Reversed-phase chromatography of proteins.

Modern liquid chromatography (LC), commonly referred to as high-performance liquid chromatography (HPLC), is over 30 yr old. Because of its age, many people might consider HPLC a mature technique and, as such, view the field as stagnant. However, nothing could be further from reality. The field of HPLC is changing rapidly although more subtly than it did in earlier years and it is interesting to note that today’s trends are in essence driven by the same application benefits that were prevalent in the early years of LC (viz. improved quantitation, rapid determination of purity and structure, and preconcentration of samples). HPLC has gained wide acceptance in the modern analytical laboratory as well as in most other areas of science.

How valid are our QA assumptions: an examination of underpinning Axioms

There is no universally accepted approach to analytical quality assurance (QA) and different laboratories place emphasis on widely different aspects. The difficulties in agreeing what constitutes best practice originate, in part, from a lack of clarity concerning the underpinning principles or axioms. This paper aims to set out some of the axioms which underpin current thinking and to discuss their validity and interplay, in order to provide a more rational, or at least transparent basis, for the evaluation of different strategies. The selection of issues and the discussion are necessarily subjective and based on the authors experience. It is concluded that current practice is generally soundly based but there is a need for a better understanding of the efficacy and cost-benefit of the various QA techniques available. Scepticism concerning the value of systems and documentation is not well founded, provided they are not taken to excess. There are, however, issues concerning the military-based command-and-control style and the engineering origins of ISO 9000 and ISO Guide 25 requirements which make them not entirely suitable for a modern analytical laboratory. There are also dangers that the command-and-control style could discourage measurement scientists from thinking for themselves or lull them into a false sense of security.

Obtaining and processing data from laboratory instruments : I. Getting the data into the Windows environment

In the modern analytical laboratory, and particularly in the teaching and research situation, analysts are confronted with the problem of processing experimental data. Invariably, instruments are linked or have the capacity to be easily linked with microcomputers, providing the user with digitised versions of the experimental signal, which can be processed in a multitude of increasingly complex ways to extract as much analytical information as possible. In Part I of this two-part article, we show how to upgrade, and more interestingly, replace some functions and improve existing analog instrumentation using a relatively cheap data acquisition card.