Interleukins proved to be valuable biomarkers for different diseases. Interleukins 1β, 6, and 12 can be used as biomarkers for brain cancer diagnosis, and therefore this paper proposed a needle stochastic sensor based on protoporphyrin IX immobilized in nano-diamond paste for fast screening of biological samples, such as whole blood, urine and brain tumoral tissue, for these interleukins. The results obtained using this needle stochastic sensor proved that the interleukins 1β, 6, and 12 can be reliably determined from whole blood, urine and brain tumoral tissue, with recoveries higher than 96.00% and with relative standard deviations lower than 1.00%. The validation of the method was performed using whole blood and tissue samples collected from the patients confirmed with brain tumor. Full article

Analytical chemistry is experiencing dramatic, turbulent change beyond laboratory and laboratory management control. Technological innovations, staffing demographics, new business models, automation, industry consolidation, society, regulatory expectations, and other factors are transforming nearly every aspect of analytical chemistry. This course takes a strategic view of the laboratory system in the context of current quality management philosophies to determine options for achieving best practices. Experiences will be shared to provide insight into the obstacles and expected outcomes for the various approaches. Furthermore, this course includes the mission and function of the analytical enterprise, along with ways to improve the quality, performance, and evaluation of the laboratory for excellent benchmarking in giant industries. Full article

One of the more technically challenging concepts in quality assurance is the appropriate quantification of the uncertainty of measurement. Consequently, there must be an adequate emphasis on didactic approaches to ascertain that the student is not just educated about pertinent aspects, but actually can apply the necessary procedures in his/her own field of expertise. “Student”, in this context, can denote very different stages in a career, from first-year students to doctoral students, as well as seasoned practitioners. Correspondingly, the teaching of measurement uncertainty can be quite diverse. In this contribution, specific examples of learning approaches towards “skills” will be provided based on past personal experience. Full article

The aim of this work was to investigate the corrosion inhibition effect of natural seaweeds in seawater on carbon steel. The corrosion efficiency of carbon steel in the absence and the presence of natural seaweeds in seawater was evaluated by the gravimetric method at room temperature and calculating the corrosion rate and protection degree. The experimental results showed that the corrosion rate on carbon steel decreased when the seaweeds were used. In addition, the value of protection degree (P) was greater than 60% when seaweeds were used. Natural seaweeds reduce the corrosion rate and can be considered an ecofriendly corrosion inhibitor for carbon steel. Full article

The (International Atomic Energy Agency) IAEA’s fundamental safety objective is to protect people and the environment from harmful effects of ionizing radiation. The safety principles apply to all facilities and all activities to reduce existing radiation risks. Analytical quality assurance has gained in importance in many scientific areas, including the analysis of radioactive specimens that require a thorough investigation and regulations for safety and ecological reasons. The use of certified reference materials is an essential pillar for the assessment of the quality of analytical data. Still, such matrix-matched certified reference materials are unfortunately not available for most investigations relevant to the nuclear domain. Therefore, other strategies have to be established, i.e., to compare the analytical results obtained for a particular instrumental technique, with data from another methodology whose analyte detection is based on a different physical principle. Full article

Nanolayer deposition(s) of Ag and AgC composite on a plastic substrate was used to design disposable stochastic sensors. The first sensor was based on an Ag nanofilm deposited on plastic; for the second sensor, an AgC composite was deposited on plastic, and, for the third sensor, on the plastic was deposited first a nanofilm of Ag and on top of it a nanofilm of the AgC composite. α-Cyclodextrin was used to modify the active surface of the sensor. Full article

The correlation between the measured values of product components can influence the total risk of false decisions in conformity assessment. This correlation can originate from the characteristics of the product (intrinsic) or from how the components are measured (metrological). This work aimed to determine both correlations by testing a medicine with two compounds separately and together (correlated). The same intrinsic correlation was estimated regardless of whether the measurements were independent or correlated. Furthermore, the intrinsic covariance contributed significantly to the total covariance between the components evaluated. Both metrological and intrinsic correlations should be considered, as they can affect the risks of false decisions in conformity assessment when there are two or more compounds associated in the product. Full article

Matrix-induced signal suppression or enhancements are known phenomena in electrospray ionization mass spectrometry. Very few studies report on method development for organic aerosols analyses with the evaluation of the matrix effects. The matrix effects lead to errors in the quantification of the analytes and affect the detection capability, precision, and accuracy of an analysis method. The present study reports on the matrix effects in the analysis of organic chemical compounds present in atmospheric aerosol particles collected on quartz filters. A total number of 19 analytes, including different classes of organic compounds, such as monoaromatic phenols and derivatives (e.g., catechol, 4-methylcatechol, 3-methoxycatechol, 4-nitrocatechol, 4-nitrophenol, 2,4-dinitrophenol, 2,6-dimethyl-4-nitrophenol), carboxylic acids (terebic acid, adipic acid, pimelic acid, phthalic acid, vanillic acid), and sulfonic acids (e.g., camphor-10-sulfonic acid), was investigated by high-performance liquid chromatography coupled to electrospray ionization time-of-flight mass spectrometry (HPLC/ESI-ToF-MS). The HPLC and ESI set-up parameters used in this study were previously optimized for the investigated compounds. Different volumes of a standard mixture were added to sample extracts, with final solutions concentrations in the 50–1500 μg L⁻¹ range. For the investigated concentration range, the observed matrix effect was independent of the standard concentration level. For quartz filter extracts, the average matrix effect determined on a concentration-based method was 109.5 ± 6.1%. Both signal suppression and enhancement effects were observed for different compounds. For other analytes, the influence of the matrix effect is variable, suggesting that the use of an internal standard is not sufficient for the matrix effects correction. Competition between analyte ions and matrix components in the gas-phase ionization processes occurring in electrospray might explain signal suppression while generated coeluted isobaric compounds might induce signal enhancement. Full article

Laboratory quality management system is a concept of utmost importance for industry and other economic sectors. Nowadays, even for university laboratories it is possible to have accredited tests according to standard ISO/IEC 17025. This paper demonstrates a way of evaluating the potential of academic experts to integrate successfully the quality management systems of a chemical analysis laboratory in the teaching process. However, designing an appropriate academic curriculum responding to our current societal needs is still very challenging. In teaching and developing practical competences in analytical quality assurance, training offered to students in aspects related to the validation of an analytical method including performance characteristics such as selectivity and specificity, linear range, sensitivity, limit of detection, limit of quantification, ruggedness, accuracy, precision, etc., are primary steps in the process of a complete understanding of quality management system topics. This contribution presents a compilation of the most important current developments in a university chemical analysis laboratory with good results in developing theoretical and practical skills in analytical quality assurance for students, graduates and postgraduates alike. Teaching students with an interdisciplinary approach allows them to gain knowledge in making connections between disciplines and theories, between practical problems and accumulated knowledge, and between society’s assumptions, expectations, and needs. Full article

Quality and reliability are essential terms in analytical chemistry. Reliable analytical information implies quality. Maintaining the quality in time shows reliability. Evaluation of quality and reliability is essential for the validation of a new method of analysis. Learning good practice in analytical chemistry during undergraduate studies will improve the quality of the laboratories of analysis, by implementing highly reliable analytical methods. Full article

Virtual screening of compound libraries for property predictions has various applications such as: prediction of oxido-reduction potentials in view of molecular recognition, drug-likeness assessment, and design of new potential therapeutic agents, quantitative structure-property and activity relationships (QSPR/QSAR) modeling to design new structures and property predictions. Available free online platforms or specialized software provide us with vital help to design, characterize and evaluate molecular features and descriptors for imaginary systems or newly synthesized ones, to establish their potential for new applications by controlling and modeling their chemical/ biochemical behavior and properties. Predictions allow us to reduce the time spent, the cost of reagents or elaborate and costly assays, and provide us enlarged and complex perspectives. Full article

: We identified and quantified by LC-MS/MS 11 (quercetin, galangin, pinocembrin, kaempferol, vanillin, chrysin, gallic acid, p-coumaric acid, trans-ferulic acid, caffeic acid, and caffeic acid phenethyl ester) out of the 21 polyphenolic compounds we looked for in ethanolic (25% and 50%) and aqueous propolis extracts by comparison with standards and literature data. Full article

The master’s degree in Applied Analytical Chemistry at University College London (UCL) includes valuable teaching input from the UK National Measurement Laboratory for Chemical and Bio-Measurement hosted at LGC. The course starts by introducing accuracy, sensitivity, specificity, trueness, and precision for validating analytical chemistry measurement methods. The principles of proficiency tests, quality control, ruggedness, and associated statistics are practiced using a wide variety of case studies. Full article

Quality represents all the characteristics and features of a product or service that satisfies individual requirements. In other words, quality is measured by the degree of customer satisfaction regarding a product or service. The implementation of the control diagram is studied at the distribution store reception of Metaxa cognac orders. The delivery was performed in boxes of six bottles. The control charts follow the degree of filling of the bottles. The volume of filling was measured on a batch of 36 bottles to establish reliable control limits. The studied sample comprised 36 bottles distributed in six boxes. Full article

Reliable, traceable, and comparable measurements provide a rational basis for evaluating the quality of any result and the starting point for laboratory accreditation. Accurate and compatible measurements are, at present, essential for manufacturing, science, and trade. Additionally, a wide range of aspects of the quality of life, from healthcare to sport, is underpinned by reliable measurement results. Starting from the role of a National Institute of Metrology (INM) in securing traceability of all measurements, regardless of their end-use or level of accuracy, some aspects related to the present state-of-art in the field of metrology in Romania are presented. Full article

It is accepted that the COVID-19 pandemic opened the interest for open learning/education, for which there are three accepted meanings: (i) open universities, (ii) massive open online courses (MOOCs), and (iii) open educational resources (OERs). In this context, this work presents the development of OERs for learning about the environmental quality monitoring system and its related activities, where environmental analysis is a critical stage part of the process. The contents of the created OERs include video presentation/commented slides, text-based learning resources, and intermediate/final tests, available for free in the public domain. Full article