Long-Term Fluorescence Behavior of CdSe/ZnS Quantum Dots on Various Planar Chromatographic Stationary Phases.

Nanoparticles, particularly quantum dots (QDs), are commonly used for the sensitive detection of various objects. A number of target molecules may be determined using QDs sensing systems. Depending on their chemical nature, physicochemical properties, and spatial arrangement, QDs can selectively interact with given molecules of interest.

Investigation of Hybrid Methods for Elimination of Brilliant Blue Dye from Water Phase Using Various Nanomaterials Combined with Activated Sludge and Duckweed.

The main goal of this experimental work is screening of different natural and synthetic nanomaterials and biopolymers that may improve elimination of stable micropollutants from water phase. In this work, as a target chemical acting as the micropollutant molecule, the Brilliant Blue (BB) dye was selected. We tested different active matrices dispersed in water phase including activated carbon (AC), lyophilized graphene oxide (GO), β-cyclodextrin (CD), raw dandelion pappus (DP), microcrystalline cellulose(MC), and raw pine pollen (PP), as well as two types of Egyptian Blue mineral pigments (EB1 and EB2).

Carbon-Based Nanomaterials as Promising Material for Wastewater Treatment Processes.

In the latest literature search, the technology based on graphite oxide (GO) nanomaterials exhibits a great potential in many aspects of wastewater treatment involving adsorption, photocatalysis, disinfection and membrane process. In this study experimental data involving the carbon element in different forms such as active carbon (AC), graphite and graphene oxide (GO) applied as the active reagents in wastewater treatment are summarized and discussed. The first step was to characterize the aforementioned carbon materials and nanoparticles using various complementary techniques.

Pilbara Craton Soil as A Possible Lunar Soil Simulant for Civil Engineering Applications.

Recent fast development in lunar exploration exposed a lack of lunar soil simulant (LSS) fit for civil engineering applications. Permanent human presence on the Moon will be associated with significant construction efforts. Adequate technologies and building materials have to be developed and tested prior to setting the actual building site on the Moon.

Degradation Studies of Selected Bisphenols in the Presence of β-Cyclodextrin and/or Duckweed Water Plant.

Background: This research reports a multivariate experiment enabling observation of the potential application of macrocyclic compound [β-cyclodextrin (β-CD)] and/or duckweed organisms as the active factors for elimination of selected bisphenols A, B, and S from water samples.

Objective: Target bisphenols selection was based on observation that such components can be present in food or environmental samples (e.g.

Smart Sampling and Probing: Are You Getting All the Relevant Information?

Background: Sampling (collecting) and probing (testing, measuring) are very common tasks in the analytical field, where we need to characterize a given system and complex samples. In this action, we try to ensemble maximal information related with the system under a given study, and, frequently, we may end an inefficient analytical situation.

Objective: The best way to avoid "oversampling" and "overprobing" is to evaluate the number of factors and objects that may be present in a current data set.

Analysis of Selected Endocrine Disrupters Fraction Including Bisphenols Extracted from Daily Products, Food Packaging and Treated Wastewater Using Optimized Solid-Phase Extraction and Temperature-Dependent Inclusion Chromatography.

The aim of this research is to demonstrate the concept and ability for the fast and preliminary screening of complex food and environmental samples for the presence of endocrine disrupters fractions, consisting of low-molecular mass micropollutants, particularly various bisphenols (A, B, C, E, F, S, Z, AF, AP, BP and FL). The developed analytical protocol for this research requires two main steps: (i) optimized solid phase extraction (SPE) for selective isolation, purification and pre-concentration of target fraction, and (ii) selective temperature-dependent inclusion chromatography for samples analysis via a HPLC-UV-VisDAD system using isocratic elution and internal standard quantification approach. The chromatographic experiment revealed that both β-CD and its hydroxypropyl derivative strongly interact with selected bisphenols.

Toward the Understanding of Micro-TLC Behavior of Various Dyes on Silica and Cellulose Stationary Phases Using A Data Mining Approach.

Planar chromatography and related techniques [micro-planar chromatography, micro-TLC, or paper-based microfluidic devices (μPADs)] present several advantages in analytical applications, such as simplicity, low cost of analysis, and the ability to work with raw complex samples without the involvement of time-consuming prepurification steps. By using commonly applied planar chromatographic systems and μPADs devices, stationary phases (silica and cellulose based), different solvent mixtures (methanol-water and dichloromethane-methanol), and proportions varying from 0 to 100% (v/v), micro-TLC migration profiles of several dyes described in terms of characteristic of chromatographic parameters (retardation factor, peak base width, and asymmetry factor) were investigated. Combining these results with some quantum mechanics calculated properties for each solute (dipole moment, polarizability), and by using the data mining approach, we modeled this overall chromatographic behavior in order to describe experimental data.

Preliminary Studies of Synthetic Dye Adsorption on Iron Sludge and Activated Carbons.

There is great interest in the search for multifunctional waste-based materials that may be applied as environmentally friendly adsorbents. Iron-rich sludge from ground drinking-water treatment plants may be considered a potential adsorbent for various water contaminants. This material is generated during ground water purification because of the excess of metal ions in water (Fe, Mn).

Dye Removal from Water and Wastewater Using Various Physical, Chemical, and Biological Processes.

Synthetic dyes or colorants are key chemicals for various industries producing textiles, food, cosmetics, pharmaceutics, printer inks, leather, and plastics. Nowadays, the textile industry is the major consumer of dyes. The mass of synthetic colorants used by this industry is estimated at the level of 1 ÷ 3 × 105 tons, in comparison with the total annual consumption of around 7 × 105 tons worldwide.

Advances in the Analysis of Water and Wastewater Samples Using Various Sensing Protocols and Microfluidic Devices Based on PAD and μTAS Systems.

The main goal of this review is to summarize practical approaches concerning the application of microfluidic systems for the analysis of various biomarkers and pollutants, as well as microbes, in water and wastewater matrixes. This problem involves multidisciplinary expertise combining research knowledge from various areas, including wet chemistry, biochemistry, physical chemistry, molecular biology, genetics, signal processing, microelectronics material science, and separation science. It has been documented that fairly primitive but fast and inexpensive screening methods involving paper-based analytical devices (PADs) and micro total analytical systems (μTAS) can be considered as serious alternatives to their more advanced counterparts such as GC, HPLC, and capillary electrophoresis coupled to various sophisticated detectors (e.

Miniaturized Temperature-Controlled Planar Chromatography (Micro-TLC) as a Versatile Technique for Fast Screening of Micropollutants and Biomarkers Derived from Surface Water Ecosystems and During Technological Processes of Wastewater Treatment.

There is increasing interest in the development of simple analytical systems enabling the fast screening of target components in complex samples. A number of newly invented protocols are based on quasi separation techniques involving microfluidic paper-based analytical devices and/or micro total analysis systems. Under such conditions, the quantification of target components can be performed mainly due to selective detection.

Unexpected differences between planar and column liquid chromatographic retention of 1-acenaphthenol enantiomers controlled by supramolecular interactions involving β-cyclodextrin at subambient temperatures.

We report the results of experimental work focusing on host-guest supramolecular complex creation between macrocyclic compound (β-cyclodextrin) and 1-acenaphthenol enantiomers (racemic mixture) in liquid phase composed of 35% acetonitrile in water (v/v) at different temperatures ranging from 0 to 90 °C. Experimental setup involved several analytical protocols based on classical non-forced flow planar chromatography (RP-18 TLC plates), micro-TLC (RP-18 W HPTLC plates), column chromatography (HPLC with C-18 and C-30 stationary phases), as well as UV-Vis spectrophotometry and optical microscopy. It has been found that under various planar chromatographic conditions (stationary plates type, chamber shape and volume, development mode, and saturation) non-typical retention properties (extremely high retention) of 1-acenaphthenol at subambient temperatures can be observed.

Supplementary evaluation of retention and physicochemical data involving multivariate analysis approach.

This commentary highlights the issue of real differences between stationary phases that were studied in an experimental paper entitled "Novel stationary phases based on asphaltenes for gas chromatography" prepared by Grzegorz Boczkaj and co-authors (J. Sep. Sci.

Recent advances in hopanoids analysis: Quantification protocols overview, main research targets and selected problems of complex data exploration.

Pentacyclic triterpenoids, particularly hopanoids, are organism-specific compounds and are generally considered as useful biomarkers that allow fingerprinting and classification of biological, environmental and geological samples. Simultaneous quantification of various hopanoids together with battery of related non-polar and low-molecular mass compounds may provide principal information for geochemical and environmental research focusing on both modern and ancient investigations. Target compounds can be derived from microbial biomass, water columns, sediments, coals, crude fossils or rocks.

New approach for sensitive photothermal detection of C60 and C70 fullerenes on micro-thin-layer chromatographic plates.

In this paper the pulse thermovision (photothermal) detection and quantification methods of C60 and C70 fullerenes are presented. Quantification results are compared with optical and fluorescence measurements. Target components were separated under isothermal conditions (30 °C) on micro-TLC plates (RP18WF254S) using n-hexane as the mobile phase.

Fast assessment of planar chromatographic layers quality using pulse thermovision method.

The main goal of this paper is to demonstrate capability of pulse thermovision (thermal-wave) methodology for sensitive detection of photothermal non-uniformities within light scattering and semi-transparent planar stationary phases. Successful visualization of stationary phases defects required signal processing protocols based on wavelet filtration, correlation analysis and k-means 3D segmentation. Such post-processing data handling approach allows extremely sensitive detection of thickness and structural changes within commercially available planar chromatographic layers.

Application of micro-TLC to the total antioxidant potential (TAP) measurement.

DPPH is commonly applied for estimation of antioxidant capacity of single and complex biological samples, and changes colour from purple to yellow during reduction to DPPH-H. Importantly, for some samples, for example coloured foods, such reaction cannot be used because of interference from pigments. Therefore, the number of reported quantitative protocols involving off- or on-line sample reaction with DPPH are based on chromatographic separation of target components.

Micro-TLC Approach for Fast Screening of Environmental Samples Derived from Surface and Sewage Waters.

In this work we demonstrated analytical capability of micro-planar (micro-TLC) technique comprising one and two-dimensional (2D) separation modes to generate fingerprints of environmental samples originated from sewage and ecosystems waters. We showed that elaborated separation and detection protocols are complementary to previously invented HPLC method based on temperature-dependent inclusion chromatography and UV-DAD detection. Presented 1D and 2D micro-TLC chromatograms of SPE (solid-phase extraction) extracts were optimized for fast and low-cost screening of water samples collected from lakes and rivers located in the area of Middle Pomerania in northern part of Poland.

Microfluidic Paper-Based Analytical Devices (μPADs) and Micro Total Analysis Systems (μTAS): Development, Applications and Future Trends.

Microfluidic paper-based analytical devices and micro total analysis systems are relatively new group of analytical tools, capable of analyzing complex biochemical samples containing macromolecules, proteins, nucleic acids, toxins, cells or pathogens. Within one analytical run, fluidic manipulations like transportation, sorting, mixing or separation are available. Recently, microfluidic devices are a subject of extensive research, mostly for fast and non-expensive biochemical analysis but also for screening of medical samples and forensic diagnostics.

Estimation of the breakthrough volume of selected steroids for C-18 solid-phase extraction sorbent using retention data from micro-thin layer chromatography.

SPE method is a very popular technique, and is commonly used for the prepurification, concentration, and isolation of different organic compounds from variable matrices. In this work, the optimization of SPE process was carried out. The breakthrough volume of solid sorbents based on octadecylsilane was determined and three methods were compared: (1) calculation one - the breakthrough volume was calculated using retention factor k determined with micro-TLC method, frontal analysis - (2) breakthrough volume was determined as volume of whole elution peak, and (3) breakthrough volume was determined as the center of peak gravity.