Themed collection ENQA - 20th Brazilian Meeting on Analytical Chemistry

Micro-FTIR imaging has opened new possibilities for investigating in situ drug release, redox chemistry effects with biological molecules, DNA and drug interactions, membranes dynamic, and redox reaction with proteins at the single cell level.

3D-printing enables the rapid prototyping of ion mobility (IMS) and mass spectrometry (MS) gadgets. The RepRap components are suitable for building cost-efficient robots and MS imaging systems. In this review, we present current trends.

Porphyrins and phthalocyanines used to construct sensors for electroanalytical drug detection.

This review provides an overview on the recent (2016–2020) findings on chemosensors based on pyrazole derivatives. The discussion focuses on the design, physicochemical properties and practical applications of probes.

Aerosol dilution (AD) is a sample introduction tool that allows the direct analysis of complex matrix samples by plasma-based analytical techniques.

New developments in instrumentation, plasma diagnostics, calibration, and sample preparation applied to MIP-OES may make it competitive with ICP-OES.

Critical review on the fundamentals, applications, challenges, and prospects of thread-based microfluidic analytical devices.

The evolution of different analytical methods that have been applied to the determination of antimalarial drugs in pharmaceutical formulations and human blood by liquid chromatography.

Rapid diagnostic tests (RDTs) will provide a key element of disease surveillance. Their rapid turnaround, low cost, and accessibility in resource limited areas will help increase public health reporting and facilitate outbreak containment.

SARS-CoV-2 and humoral response determinations to understand and control the spread of COVID-19.

The extensive use of pesticides leads to soil contamination and is harmful to environmental health.

The extraction and quantification of leaf pigments are easy, fast, and cheap procedures; on the other hand, DRIFT spectroscopy associated with chemometrics tools could offer new insights into leaf biochemical composition.

We introduce a simple, scalable, and portable electrochemical aptamer-based system for detection of the SARS-CoV-2 spike protein in saliva with attomolar sensitivity.

Colorimetric LAMP for COVID-19 intensified diagnostics: a simple and quantitative method comparable in diagnostic performance to RT-qPCR.

This study presents a novel approach for the simultaneous detection of ascorbic acid (AA) and dopamine (DA) using an affordable and user-friendly microfluidic device.

Accurate and precise online extraction and determination of free glycerol in biodiesel exploiting pulsed flows.

Experimental design as an optimization protocol of mass spectrometry parameters towards the acquisition of high quality datasets for metabolomics-driven investigations.

Urea is an essential molecule usually detected using spectroscopy, particularly ultraviolet and visible spectroscopy (UV-vis).

To meet the substantial trend towards NIR spectroscopy miniaturization, this work compared benchtop and portable NIR instruments to discriminate Robusta Amazônico samples using partial least squares discriminant analysis (PLS-DA).

We present the electrochemical detection of mephedrone in forensic samples using independent redox processes of synthetic cathinones on a graphene screen-printed electrode.

Simultaneous determination of Cl⁻, NO₂⁻, NO₃⁻, SO₄²⁻, and HCO₃⁻ in shrimp-farming water samples by CZE-UV using dilution as sample pretreatment step. Mixture design was used to optimize the composition of the electrolyte background.

We developed an artificial neural network method for characterising crucial physical plasma parameters (i.e., temperature, electron density) in a fast and precise manner that mitigates common issues arising in evaluation of LIBS spectra.

This work presents for the first time the use of ion-imprinted magnetic materials in a simple and novel flow-through magnetic preconcentration system applied to the determination of ultratraces of cadmium ions in water coupled to GFAAS.

The retention behavior of a dangerous toxin, ochratoxin A (OTA), present in food samples and derivatives was evaluated using Layered Double Hydroxides (LDHs).

The potential of THz spectroscopy in the development of analytical applications for saccharide identification.

An alternative yet powerful methodology based on the colorimetric sensor array concept to distinguish green tea extract through the flavonoid composition.

Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was applied for the determination of Br and I in hair strands of human individuals under treatment with synthetic thyroid hormones.

This work aims to study and apply filter paper as calibration solid supports, in order to avoid matrix and fractionation effects, for the quantification of two essential elements of trees, Cu and Zn, in tree-ring samples, using LA-ICP-MS.

The procedure does not require organic solvents and is based on easy CPE of sulphonamides from milk samples. Established limits for total sulphonamides in milk were met using digital images.

The absorption efficiency of chemically resolved organic aerosols of Southwestern Amazonia showed strong spectral dependence and significant light absorption in the UV-vis wavelength range indicating the presence of organic species that act as BrC.

A single reaction chamber microwave-assisted wet digestion system using O₂ as an auxiliary reagent and diluted HNO₃ for multisample digestion and metal determination.

An NH₂-surface-coated wooden-tip electrospray ionization mass spectrometry method was developed for naphthenic acid analysis in water samples.

This study reports the simultaneous colorimetric detection of urea, H₂O₂, and pH in milk samples using microfluidic paper-based analytical devices (μPADs) fabricated through a craft cutter printer.

In this work a simple and novel procedure for leucomalachite green determination based on micro flow injection analysis (μFIA) with amperometric detection is presented.

Photochemical vapor generation of Os. OsO₄ oxidative product from photolysis of 5% HNO₃ medium; reductive product from 1% acetic acid/50 mg L⁻¹ Fe^3/2+ an uncharacterized organometallic Os compound [Os_w(CO)_x(CH₃)_yH_z] detected by ICP-MS.

The interactions between NPs and a binary system of proteins were studied through a systematic set of capillary electrophoresis models. The results revealed precise details of the soft and hard protein corona formation and dynamics.

We developed a molecular test for the detection of SARS-CoV-2 directly from swab samples. The test is based on colorimetric RT-LAMP, with results comparable to the gold standard method (RT -qPCR), performed in a hospital and laboratory environment.

The relationship between oxygen content and toxicity in graphene oxide varies between species.

On-line and green automatic methods with spectrophotometric detection were developed to the obtention of permeation kinetic constants of octyl p-methoxycinnamate in o/w microemulsions. The effect of interferences was overcome using chemometric tools.

Cocaine is probably one of the most trafficked illicit drugs in the world.

Two gas phase sampling systems were validated and compared to each other. The levels of pesticides ranged between 192 and 1731 pg m⁻³. Human exposure to pesticides was estimated using the gas phase concentrations.

A fully 3D-printed microfluidic thread-based device containing an embedded electrochemical detector is first reported. A green method based on microflow injection analysis for sensing of nitrite ions in environmental samples is also first presented.

We developed a low-cost molecular test for the diagnosis of COVID-19, in a centrifugal microdevice, based on RT-LAMP assay run at 72 °C for 10 min.

In this work, we present a combination of ssNMR spectroscopy and two different theoretical methods to get a full description of an intramolecular hydrogen bond in tizoxanide.

A sensitive analytical method was developed that simultaneously characterizes 25 unregulated DBPs in wastewater effluents. DBP formation potential with HOCl and NH₂Cl was evaluated across a full-scale wastewater reuse facility for the first time.

This work describes a novel technique for the direct quantification of Acid Green 16 (AG16) adsorbed on a molecularly imprinted polymer (MIP) through the application of diffuse reflectance spectrophotometry (DRS) directly in a slid material.

This study calls attention to the primary emissions of semivolatile oxygenated organic compounds (SV-OVOCs) and demonstrates how mapping out the near-canopy concentration can effectively isolate atmospheric SV-OVOC production from direct emissions.

In this investigation, an organic monolithic material of poly(GMA-co-EDMA) was functionalized with a peptide via Michael addition chemistry for isolating and pre-concentrating antibodies.

One-step enzyme-free dual electrochemical immunosensor for Malaria biomarker determination.

Boron Schiff bases derived from amino acids show nucleoli and cytoplasm staining fluorescent probes with good photostability and low cytotoxicity, which make them candidates to be used in medical diagnosis.

This study presents the first local measurements of metals in snow from the Argentine Central Andes.

Herein, we establish a new perspective towards economically viable non-toxic fluorescent probes as a potential substitute of expensive alternative for the detection of MeOH in alcoholic beverages.

A new, inexpensive and easy to use 3D printable device was developed for nephelometric and fluorimetric determination.

Standard Dilution Analysis (SDA) as a more environmentally friendly and time saving calibration method for multielement determination in biodiesel by ICP OES.

A method was developed to determine Hg in crude oil at sub-ppb levels by cold vapor generation inductively coupled plasma mass spectrometry (CV-ICP-MS) after wet digestion in a microwave-assisted system with a pressurized cavity.

The beer industry plays an important role in the economy since this is the third most consumed beverage worldwide.

Magnetic nanoparticles of GO–γ-Fe₂O₃ were applied for the preconcentration of Se in fish samples and determination by hydride generation atomic absorption spectrometry and flow injection analysis.