A Multi-Pumping Gradient Calibration Module for Potentiometric Determination of Nitrate in Surface Water.

The novel, automated, multi-pumping flow system (MPFS) for online calibration and determination of nitrate in surface water is presented for the first time. The system was equipped with micropumps of three different nominal volumes (10, 20, and 50 µL). As a result, it was possible to prepare from one standard, directly in a flow system, up to seven standard solutions.

Electrochemical Sensing of Pb and Cd Ions with the Use of Electrode Modified with Carbon-Covered Halloysite and Carbon Nanotubes.

A novel voltammetric method for the sensitive and selective determination of cadmium and lead ions using screen-printed carbon electrodes (SPCEs) modified with carbon-deposited natural halloysite (C_Hal) and multi-walled carbon nanotubes (MWCNTs) was developed. The electrochemical properties of the proposed sensor were investigated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), while the morphology and structure were established by scanning electron microscopy (SEM) and X-ray powder diffraction (XRD). A two-factorial central composite design (CCD) was employed to select the composition of the nanocomposite modifying the electrode surface.

Application of Capillary Electromigration Methods in the Analysis of Textile Dyes-Review.

Fiber traces are one of (micro)traces that can be found at a crime scene. They are easily transferable and, like other forms of evidence, can provide a link between a suspect and a victim. The main purpose of this review is to present methods developed to examine textile dyes extracted for forensic purposes using different capillary electromigration methods (CEMs).

The Use of an Acylhydrazone-Based Metal-Organic Framework in Solid-Contact Potassium-Selective Electrode for Water Analysis.

A solid-contact ion-selective electrode was developed for detecting potassium in environmental water. Two versions of a stable cadmium acylhydrazone-based metal organic framework, i.e.

Novel Integrated Flow-Based Steam Distillation and Titration System for Determination of Volatile Acidity in Wines.

Novel integrated flow-based steam distillation and titration system with spectrophotometric detection was developed for determination of volatile acidity in wines. Using the system, the distillation procedure was carried out in an automatic manner, starting with introducing into a heated steam distillation module a sample and subjecting it to steam distillation. Under selected conditions, all the analyte was transferred to the distillate; therefore, the system did not require calibration.

A multitechnique approach for discrimination and identification of lipsticks for forensic purposes.

Cosmetics are becoming more and more popular; consequently, the chance of finding them as microtraces at a crime scene increases. They are easily transferable and can provide a link between a suspect and a victim. For this reason, identifying and comparative analysis of red lipstick - the most popular and used - is required.

A Perspective of the Comprehensive and Objective Assessment of Analytical Methods Including the Greenness and Functionality Criteria: Application to the Determination of Zinc in Aqueous Samples.

The recently proposed concept of White Analytical Chemistry (WAC), referring to the Red-Green-Blue color model, combines ecological aspects (green) with functionality (red and blue criteria), presenting the complete method as "white". However, it is not easy to carry out an overall quantitative evaluation of the analytical method in line with the WAC idea in an objective manner. This paper outlines the perspective of the future development of such a possibility by attempting to answer selected questions about the evaluation process.

An Automated Hydrodynamically Mediated Technique for Preparation of Calibration Solutions via Capillary Electrophoresis System as a Promising Alternative to Manual Pipetting.

In this paper, a novel procedure for preparing calibration solutions for capillary electrophoresis (CE)-based quantitative analysis is proposed. Our approach, named the automated hydrodynamically mediated technique (AHMT), uses a capillary and a pressure system to deliver the expected amount of working solution and diluent directly to a sample vial. As a result, calibration solutions are prepared automatically inside the CE instrument, without any or with minimal manual operation.

Comprehensive Assessment of Flow and Other Analytical Methods Dedicated to the Determination of Zinc in Water.

An original strategy to evaluate analytical procedures is proposed and applied to verify if the flow-based methods, generally favorable in terms of green chemistry, are competitive when their evaluation also relies on other criteria. To this end, eight methods for the determination of zinc in waters, including four flow-based ones, were compared and the Red-Green-Blue (RGB) model was exploited. This model takes into account several features related to the general quality of an analytical method, namely, its analytical efficiency, compliance with the green analytical chemistry, as well as practical and economic usefulness.

3D-printed manifold integrating solid contact ion-selective electrodes for multiplexed ion concentration measurements in urine.

Urinalysis is a simple and non-invasive approach for the diagnosis and monitoring of various health disorders. While urinalysis is predominantly confined to clinical laboratories the non-invasive sample collection makes it applicable in wide range of settings outside of central laboratory confinements. In this respect, 3D printed devices integrating sensors for measuring multiple parameters may be one of the most viable approaches to ensure cost-effectiveness for widespread use.

Modern Flow Analysis.

A brief overview of articles published in this Special Issue of Molecules titled "Modern Flow Analysis" is provided. In addition to cross-sectional and methodological works, there are some reports on new technical and instrumental achievements. It has been shown that all these papers create a good picture of contemporary flow analysis, revealing the most current trends and problems in this branch of flow chemistry.

3D-printed flow manifold based on potentiometric measurements with solid-state ion-selective electrodes and dedicated to multicomponent water analysis.

A 3D-printed flow manifold dedicated to potentiometric simultaneous determination of potassium, sodium, calcium and chloride in water is presented. The method is based on application of miniature solid-contact ion selective electrodes with a special design obtained with the use of 3D printing. The electrodes offer many attractive advantages including short response time and miniaturization feasibility.

Novel Approach to Sample Preconcentration by Solvent Evaporation in Flow Analysis.

A preconcentration module operated in flow mode and integrated with a sequential injection system with spectrophotometric detection was developed. Using the system, preconcentration was performed in continuous mode and was based on a membraneless evaporation process under diminished pressure. The parameters of the proposed system were optimized and the system was tested on the example of the spectrophotometric determination of Cr(III).

Novel Approach to Automated Flow Titration for the Determination of Fe(III).

A novel approach to automated flow titration with spectrophotometric detection for the determination of Fe(III) is presented. The approach is based on the possibility of strict and simultaneous control of the flow rates of sample and titrant streams over time. It consists of creating different but precisely defined concentration gradients of titrant and analyte in each successively formed monosegments, and is based on using the calculated titrant dilution factor.

Application of spectroscopic and separation techniques to the examination of the chemical composition stability of lipsticks exposed to various factors and storage conditions.

In this study, the stability of the chemical composition of lipsticks after exposure to various factors (substrate, time, individual variability, the impact of smoking, the effect of consuming beverages) and storage conditions (laboratory, insolation, without access to light) was examined. The following three analytical methods were used in the study: Attenuated Total Reflection technique (ATR), Gas Chromatography coupled to Mass Spectrometry (GC-MS) and Micellar Electrokinetic Capillary Chromatography (MEKC). Seven red lipsticks characterized by different chemical composition were analyzed.

Acidity constant of pH indicators in the supramolecular systems studied by two CE-based methods compared using the RGB additive color model.

Acid-base properties of methyl orange, bromocresol green, bromophenol blue, and bromothymol blue were thoroughly investigated in the past due to their application as colorimetric pH indicators. However, it is still unknown how these properties change upon the supramolecular host-guest interactions. Owing to the growing interest in using supramolecular host-guest interactions to reach expected modification of various physicochemical properties of guests, we decided to address this question in the present article.

Employment of electrostriction phenomenon for label-free electrochemical immunosensing of tetracycline.

The presented work describes a simple label-free electrochemical immunosensor for the determination of tetracycline (TC). The functioning of the sensor was based on the electrostriction of a antibody-terminated thiol layer self-assembled on a gold electrode surface, serving as a dielectric membrane. The intensity of electrostriction was correlated with the amount of TC captured through an affinity reaction with its specific antibody, and was followed in the form of capacitance-potential curves.

Serum trace elements profile in the pediatric inflammatory bowel disease progress evaluation.

Introduction: Inflammatory bowel disease (IBD), a chronic inflammatory disorder of gastrointestinal tract, arises from complex interaction between genetics, environment, gut microbiota and mucosal immune response. Along with clinical, endoscopic and radiological evaluation various biomarkers are needed as an additional diagnostic tool, as well as to predict disease course and therapeutic outcomes.

Aim: The aim of this study was to evaluate clinical value of essential trace elements (ETEs) serum concentration profile in the assessment of pediatric IBD diseases development.

What Color Is Your Method? Adaptation of the RGB Additive Color Model to Analytical Method Evaluation.

Evaluation of an analytical method is a fundamental problem in analytical chemistry, and it is never straightforward. In this article, we show a perspective for facing this issue using an original tool. We propose a model that allows one to evaluate any analytical method/procedure in a global manner.

Dried blood spots sampling in case samples deprived of hematocrit level information - Investigation and calculation strategy.

The application of a new calculation strategy for the psychotropic drug concentration in blood and bone marrow samples in the form of dried blood spots (DBS) was the main aim of the study. The standard DBS method consists of the deposition of the capillary blood onto the dedicated paper cards. Nowadays, the DBS technique is seen as a fast and partly superior microsampling alternative methodology replacing the conventional venous blood and plasma collection.

Application of micellar electrokinetic capillary chromatography to the discrimination of red lipstick samples.

The main aim of this study was to apply capillary electrophoresis (CE) to the discrimination of red lipsticks - the first step towards developing the methodology for forensic purposes. The separation method was optimized using a mixture of eight dyes and micellar electrokinetic capillary chromatography (MEKC). The influence of the buffer pH and the concentration of SDS on the separation of dye mixtures was investigated.

Cyclodextrin-induced acidity modification of substituted cathinones studied by capillary electrophoresis supported by density functional theory calculations.

This paper shows that the acidity of substituted cathinones can change in a diversified and poorly predictable manner upon supramolecular interaction with cyclodextrins used as buffer additives in capillary electrophoresis. The direction and range of pK shifts may be noticeably different for the particular cyclodextrins and cathinones, suggesting a strict correlation with structure. The most interesting results were observed for 2-hydroxyethyl-β-cyclodextrin, which is capable for inducing the large negative and enantioselective apparent pK shifts for α-pyrrolidinovalerophenone and methylenedioxypyrovalerone, even much above -1.

Development and evaluation of semi-destructive, ultrasound assisted extraction method followed by gas chromatography coupled to mass spectrometry enabling discrimination of red lipstick samples.

In this study, the effective and robust semi-destructive ultrasound assisted extraction (UAE) method followed by gas chromatography coupled to mass spectrometry (GC-MS) method used for analysis of red lipsticks samples was developed, optimized and evaluated. 43 red lipsticks of a very similar hue representing of 21 different manufacturers were investigated. The red lipsticks (approximately 0.