Analyte Concentration Research Articles

A Tissue Distribution Study of Propafenone in an Intentional Fatal Poisoning Case

Propafenone (PPF) belongs to the class 1C antiarrhythmics and can cause electrocardiogram-associated adverse/toxic effects. Cases of PPF intoxication are rarely investigated. We developed a novel and selective GC-MS/MS method for the determination of PPF and its tissue distribution in an intentional fatal poisoning case, which is applicable to PPF quantification in the range of therapeutic to lethal concentrations in complex post-mortem samples. A simple and effective sample pretreatment was applied to all analyzed samples. PPF was determined without the need for dilution, even in highly complex samples containing a wide range of analyte concentrations. Quantification was performed using the standard addition method, developed and validated according to the ICH M10 guidelines. The obtained results indicated that the PPF concentration in the serum from blood taken while alive, before therapy, was the highest ever reported in the literature. Despite the intensive therapy after the patients’ admission, the PPF concentrations in the lungs, spleen, femoral blood and cardiac blood were fatal or abnormally high. On the other hand, the concentrations in the liver and skeletal muscle were lower or approximately the same as observed in cases with therapeutic doses. To the best of our knowledge, the distribution of PPF has not been investigated in fatal intoxication cases and can be helpful in clinical or forensic toxicology.

A Portable Readout System for Biomarker Detection with Aptamer-Modified CMOS ISFET Array

Biosensors based on ion-sensitive field effect transistors (ISFETs) combined with aptamers offer a promising and convenient solution for point-of-care testing applications due to the ability for fast and label-free detection of a wide range of biomarkers. Mobile and easy-to-use readout devices for the ISFET aptasensors would contribute to further development of the field. In this paper, the development of a portable PC-controlled device for detecting aptamer-target interactions using ISFETs is described. The device assembly allows selective modification of individual ISFETs with different oligonucleotides. Ta2O5-gated ISFET structures were optimized to minimize trapped charge and capacitive attenuation. Integrated CMOS readout circuits with linear transfer function were used to minimize the distortion of the original ISFET signal. An external analog signal digitizer with constant voltage and superimposed high-frequency sine wave reference voltage capabilities was designed to increase sensitivity when reading ISFET signals. The device performance was demonstrated with the aptamer-driven detection of troponin I in both reference voltage setting modes. The sine wave reference voltage measurement method reduced the level of drift over time and enabled a lowering of the minimum detectable analyte concentration. In this mode (constant voltage 2.4 V and 10 kHz 0.1Vp-p), the device allowed the detection of troponin I with a limit of detection of 3.27 ng/mL. Discrimination of acute myocardial infarction was demonstrated with the developed device. The ISFET device provides a platform for the multiplexed detection of different biomarkers in point-of-care testing.

Bifunctional oxidase-peroxidase mimicking Fe–Ce MOF on paper-based analytical devices to intensify luminol chemiluminescence: Application for measuring different sugars with a smartphone readout

This study presents a potent paper-based analytical device (PAD) for quantifying various sugars using an innovative bi-nanozyme made from a 2-dimensional Fe/Ce metal-organic framework (FeCe-BTC). The MOF showed excellent bifunctional peroxidase-oxidase activities, efficiently catalyzing luminol's chemiluminescence (CL) reaction. As a peroxidase-like nanozyme, FeCe-BTC could facilitate the dissociation of hydrogen peroxide (H2O2) into hydroxyl radicals, which then oxidize luminol. Additionally, it was also discovered that when reacting with H2O2, the MOF turns into a mixed-valence MOF, and acts as an oxidase nanozyme. This activity is caused by the generated Ce4+ ions in the structure of MOF that can directly oxidize luminol. The MOF was directly synthesized on the PAD and cascaded with specific natural enzymes to establish simple, rapid, and selective CL sensors for the measurement of different sugars. A cell phone was also used to record light intensities, which were then correlated to the analyte concentration. The designed PAD showed a wide linear range of 0.1–10 mM for glucose, fructose, and sucrose, with detection limits of 0.03, 0.04, and 0.04 mM, respectively. It showed satisfactory results in food and biological samples with recovery values ranging from 95.8 to 102.4 %, which makes it a promising candidate for point-of-care (POC) testing for food control and medicinal purposes.

Exploring advanced strategies in SPME-HPLC-DAD: Enhancing analytical precision and diverse applications in modern era

In analytical chemistry, the synergy between innovative sample preparation techniques and advanced chromatographic methods has paved the way for unprecedented advancements in the analysis of complex samples. Solid Phase Microextraction (SPME) stands out as a powerful tool for extraction, and preconcentration. When coupled with High-Performance Liquid Chromatography (HPLC) equipped with a Diode Array Detector (DAD), the integrated SPME-HPLC-DAD system emerges as a sophisticated analytical platform, offering enhanced sensitivity, selectivity, and versatility for various applications. Desorption is accomplished by either depositing organic solvent in the desorption chamber or else by flowing the mobile phase through the desorption chamber specificity. An ordinary description, along with a visual illustration, has been thoroughly provided for concepts of developed well-known enhanced thin film SPME cartridges (Figure 2). The tabular representation is also available with proper description like technique name, targeted analyte, column used, mobile phase used, %RSD, extraction recovery, LOD, and data acquired R2 also considered Based on the information available in the present study. Discussed SPME with HPLC-DAD brings a great turning point by successfully utilization in biomedical sciences, environmental monitors, food safety, and clinical analysis This cost-effective, readily available technique is both environmentally friendly and stable, allowing for rapid, reliable, and accurate measurements across a wide range of analyte concentrations, thanks to the utilization of hyphenated techniques. The different strategies of SPME with HPLC -DAD and possible future apllications have been incorporated in the review. The understanding of these techniques is still limited and challenging.

A self-driven multifunctional microfluidic sweat analysis system for efficient sweat collection and real-time monitoring

Wearable sweat sensors offer the opportunity for non-invasive and real-time monitoring of metabolite information in sweat, enabling individuals to dynamically monitor their physiology states at the molecular level. However, sweat possesses characteristics such as small volume, volatility, susceptibility to epidermal contamination, and low analyte concentrations, making its reliable collection and detection challenge for wearable sweat sensors. In this work, we develop a self-driven multifunctional microfluidic sweat analysis system (SMMSAS) for efficient sweat collection and detection. The SMMSAS features with a wetting contrast for the sweat, which comprises superhydrophobic inlet, superhydrophilic microchannel enriched with nanofiber, and an absorbent test paper. Such a feature enables the spontaneous sweat transports in the form of dropwise due to the exertion of “Laplace force-capillary force-capillary force” on sweat, thereby facilitating the real-time sweat detection. SMMSAS integrated with the functions of impedance and colorimetry analysis is able to simultaneously record the multiple information in sweat, including sweat volume, sweating rate, total electrolyte concentration, glucose concentration, and pH value, all of which are important to reflect the physiological state of the human body. We also demonstrate the capability of SMMSAS in real-time monitoring the sweating conditions of the human body, which is attributed to its fast responsiveness (∼ 100 ms) for the wide range sweating rate (0.5−15 μL/min) and various total electrolyte concentration (0−80 mM), paving the way for next-generation personalized healthcare.

Chiroptically active copper clusters as platform for enantioselective detection of lysine.

Metal clusters have drawn considerable research attention over the years due to their fascinating optical properties. Owing to their appealing photophysical characteristics, these materials have drawn attention as potential candidates for various application in diverse fields, including disease detection, biosensing, chemical sensing, and the fabrication of light-harvesting materials. Presently, there is an increasing research focus on the use of clusters in biomedical research, both as biodetection platform and as bioimaging agents. Of special interest are chiral clusters, which can selectively interact with chiral biomolecules owing to their optical activity. Herein, we showcase the use of a pair of chiroptically active copper clusters for the enantioselective detection of lysine, an amino acid of vast biological relevance. Two techniques are concurrently employed for the detection of lysine at varying concentrations. Circular dichroism serves as a potent tool for detecting lysine at low concentrations, whereas luminescence is effectively employed as a detection method for high analyte concentrations. The combined electronic impact of clusters and lysine resulted in the emergence of an enhanced enantioselective Cotton effect at specific wavelength.

Converting waste into value: The sample stability of leftover EDTA whole blood. A comparative study of analyte concentrations in plasma separated from EDTA whole blood at various time intervals and serum for nine clinical chemistry analyses

Converting waste into value: The sample stability of leftover EDTA whole blood. A comparative study of analyte concentrations in plasma separated from EDTA whole blood at various time intervals and serum for nine clinical chemistry analyses

Blue Ocean Strategy in the Soccer Sector: A Real Madrid Case Study

The present study aims to analyze the management actions adopted by the Real Madrid club through the lens of the Four Actions Framework of the Blue Ocean Strategy. It is a systematic literature review using the methodology Methodi Ordinatio and employs content analysis as the analytical approach. Searches were conducted in the Web of Science, Science Direct, and Scopus databases in May 2023. The research portfolio included 19 articles. The analytical content analysis procedure was carried out using NVivo Pro 14 software. Applying the Blue Ocean Four Actions Framework provided insights into Real Madrid's management strategies and business success. The findings illuminate various aspects of Real Madrid's operations, encompassing website structure, values, communication strategies, management approaches, financial performance, and areas for potential enhancement. Keywords: Blue Ocean Four Actions Framework, Real Madrid club de fútebol, management strategies, soccer club management.

Tailorable janus plasmonic SERS platform with hotspots integrating and analytes enriching property for multiple sensing

Electromagnetic hotspot engineering plays a crucial role in surface-enhanced Raman scattering (SERS) biosensors. However, the construction of optical hotspots with high density and the concentration of analytes into hotspot centers remain challenging tasks. Additionally, achieving high sensitivity and signal reproducibility in SERS biosensors is an ongoing challenge. In this study, we utilise Janus micro/nano arrays to develop a superhydrophobic SERS platform. The high roughness of these arrays facilitates the distribution of rich hotspots ranging from nano to microscale and encourages the concentration of analytes within hotspot centers. The Janus plasmonic micro/nano arrays were meticulously crafted through the synergy of site-specific growth and instant interfacial assembly of nanoparticles (NPs). In the realm of SERS measurements targeting organic dyes in river water, our sensing platform demonstrates high sensitivity (limit of detection (LOD): 10−9 M) and signal reproducibility (relative standard deviation (RSD)=4.25%). Furthermore, the SERS platform exhibited remarkable sensitivity to multiple dyes in river water. Thus, our superhydrophobic SERS platform lays the groundwork for sensitive analysis in diverse fields such as environmental analysis and healthcare monitoring.

Performance Analysis of Nanowire ISFET Biosensor Towards Bovine Serum Albumin and Liposome

Proteins are necessary to all living organisms for both structural and functional reasons. However, due to their breakdown, some proteins, including Bovine Serum Albumin (BSA) and Liposome, could cause detrimental effects on cells and tissues. Due to its high detection sensitivity, the potential for mass production, and affordable manufacture, the ion-sensitive field-effect transistor (ISFET) biosensor has become increasingly prominent in clinical research for the detection of biomolecules. BSA and Liposome are the target proteins, while collagen is the bioreceptor. ISFET biosensor with a structure of cylindrical nanowire was simulated and examined. The settling time and sensitivity of the biosensor were modeled using Nanohub BioSensorLab software. The cylindrical nanowire ISFET biosensor can be enhanced by reducing the buffer ion concentration, increasing the radius, and increasing the oxide thickness. Compared to liposomes, BSA provides a lower settling time. This is because the diffusion coefficient of liposomes is 3.6 times lower than BSA. Furthermore, settling time is reduced when the analyte concentration is increased. The results are compared with planar ISFET, considered one-dimensional (1D) architecture. The planar ISFET exhibited a quicker settling time than the cylindrical nanowire biosensor. Furthermore, as the amounts of protein and analyte increased, the settling time reduced. The cylindrical nanowire biosensor needs to be in radius of 100nm and 10nm of oxide thickness with 0.1M buffer concentration for it to achieved the highest sensitivity. These results could facilitate researchers to produce the desirable ISFET sensor for different types of proteins.

Differences in Volatile Profiles and Sensory Characteristics in Plum Spirits on a Production Scale

The specific sensory properties attributed to distillates from different plum varieties are intricately linked to aromatic substances, fruit quality, and technology employed during production. This study compares four plum brandies, each made from a renowned plum variety: Presenta, Valjevka, Čačanská lepotica, and Čačanská rodná on a production scale. Analytical and sensory profiles were assessed using GC-FID, an available analytical method advantageous for monitoring industrial fruit distillate production. Between 71 and 85 analytes were detected in the distillates, with the Presenta plum distillate containing the highest number of substances. Statistically significant differences in analyte concentration between plum varieties (p < 0.05) were observed for 11 analytes. The comparison of analytical profiles and sensory evaluation revealed that a high concentration of 1-propanol, despite its negative sensory perception, significantly impacts the overall perception of a distillate, contrasting with substances like acetaldehyde and propyl acetate, which have positive sensory evaluations but lesser significance in content. Our work identified key compounds and procedures that can be used as benchmarks for production of plum brandy with positive sensory evaluation. These findings demonstrate the broad application potential of GC-FID in fruit distillate production as an independent tool for aromatic profile assessment and quality control.

MOF-based probes for total content detection of Ca2+/Sr2+----Regulating detection performance indicators of probes via "paramagnetic/diamagnetic heterometallic probes" strategy

Probes based on luminescence metal–organic frameworks (LMOFs) have been extensively investigated. Although many of the probes can detect multiple analytes individually, it has not been reported that the probes can detect the total content of multiple analytes simultaneously. Herein a series of isostructural MOFs ([MgxMn1-x(L1)(DMSO)2]) were constructed via a strategy utilizing paramagnetic/diamagnetic heterometallic probes, which can be used for detecting Ca2+/Sr2+ individually or simultaneously without discrimination through a structural transformation mechanism. In-depth investigations reveal that probes involving such mechanism possess distinct advantages in total content detection, and one noteworthy characteristic of the probes is they exhibit similar working curves for different detectable analytes. By adjusting the ratio of paramagnetic/diamagnetic metal ions in the probes, their detection performance indicators can be precisely regulated. This work not only develops a new strategy for the customization of probe with specific performance indicators, but also opens up fresh opportunities to construct probes for total content detection.

Analysis of Different Nanostructures of ISFET Biosensors Towards Liposome Detection

Proteins are needed by all living cells for structural and functional purposes. However, some proteins such as liposome instability may result in medication leaks that could harm cells. The detection of liposomes is dependent on the complex interactions between proteins, which are necessary for both their structural integrity and functional characteristics. This emphasizes the critical role that proteins play in the precise identification and examination of liposomal structures. Ion-sensitive field-effect transistor (ISFET) biosensor has gained popularity in the clinical research field for biomolecule detection due to its high detection sensitivity, mass-production capability, and low manufacturing cost. Nanohub BioSensorLab software was used to analyze the performance of different structures of ISFET (planar, cylindrical nanowire, nanosphere and double-gate FET) by simulating the settling time and selectivity of the biosensors. As the structural dimension expands from 1D to 3D, the settling time increases by three folds at the lowest analyte concentration. The fastest settling times were achieved by planar ISFET and double-gate FET. For selectivity measurements, an enhanced selectivity was achieved by increasing the concentration of the target molecule and decreasing the concentration of the parasitic molecule. A higher selectivity is determined by the higher Signal-to-Noise Ratio (SNR) value. The SNR increased linearly corresponds to the increase in the concentration of the target molecule as well as the decrease in the parasitic molecule’s concentration. The parasitic molecule's size increase of 1 nm causes a rise in SNR of 5.00×103.

Single Voltammetric Sweep Calibration-Free Interrogation of Electrochemical Aptamer-Based Sensors Employing Continuous Square Wave Voltammetry.

Continuous square wave voltammetry (cSWV) is a technique that enables the continuous collection of current data (at 100 kHz) to maximize the information content obtainable from a single voltammetric sweep. This data collection procedure results in the generation of multiple voltammograms corresponding to different effective square wave frequencies. The application of cSWV brings significant benefits to electrochemical aptamer-based (E-AB) sensors. The E-AB sensor platform permits continuous real-time monitoring of small biological molecules. Traditionally, E-AB sensors report only on changes in analyte concentration rather than absolute quantification in matrices when basal concentrations are not known a priori. This is because they exhibit a voltammetric peak current even in the absence of a target. However, using a dual-frequency approach, calibration-free sensing can be performed effectively, eliminating the sensor-to-sensor variation by taking ratiometric current responses obtained at two different frequencies from two different voltammetric sweeps. In employing our approach, cSWV provides a great advantage over the conventionally used square wave voltammetry since the required voltammograms are collected with a single sweep, which improves the temporal resolution of the measurement when considering the current at multiple frequencies for improved accuracy and reduced surface interrogation. Moreover, we show here that using cSWV provides significantly improved concentration predictions. E-AB sensors sensitive to ATP and tobramycin were interrogated across a wide range of concentrations. With this approach, cSWV allowed us to estimate the target concentration, retaining up to an ±5% error of the expected concentration when tested in buffer and complex media.

Simultaneous Determination of Fipronil, Permethrin and their Key Related Substances in a Topical Drug Product by a Single Stability Indicating High Performance Liquid Chromatography Method.

The topical veterinary drug product containing fipronil and permethrin provides an effective repellent protection and high insecticidal efficacy for dogs. The objective of this study was to develop a stability indicating high performance liquid chromatography (HPLC) method for simultaneous detection and quantification of fipronil, permethrin, their key degradation products and butylated hydroxytoluene (BHT) in a topical drug product. The two active ingredients, their degradation products, and the antioxidant (BHT) were separated by a gradient elution on a Phenomenex Kinetex C18 column (150 × 3 mm, 2.6 µm particle size) maintained at 37 °C with H2O/acetonitrile/isopropyl alcohol/85% H3PO4 (65.5 + 32.5 + 4/0.0053, v/v/v/v) as mobile phase-A and acetonitrile (100%) as mobile phase-B. The flow rate was 0.9 mL/min and analytes were detected and quantified at 235 nm. Specificity of the method was demonstrated by adequate separation of fipronil, permethrin, their degradation products, and BHT in the forced degraded finished product. Linearity of the method was demonstrated in the range of 0.2% to 150% of target analytical concentration of both active ingredients and 50% to 150% for BHT. Excellent recoveries of fipronil, permethrin and BHT in placebo spiked active ingredient solutions in the linearity range showed sufficient accuracy of the method. LOQ and LOD of the method were determined to be 0.2% and 0.07% of the analytical concentration. A robustness study did not identify any critical parameter that adversely effected the separation and quantification. Here, we report the development and validation of a robust, stability indicating HPLC method for identification and assay of fipronil, permethrin, and BHT, including estimation of fipronil's and permethrin's degradation products in a topical drug product for dogs. The new HPLC method permits the acquisition of data for all analytes of interest for a topical finished drug product containing fipronil, permethrin, and BHT.

Colorimetric sensor array for versatile detection and discrimination of model analytes with environmental relevance

In the current work, a rapid, simple, low-cost, and sensitive smartphone-based colorimetric sensor array coupled with pattern-recognition methods was proposed for the determination and differentiation of some organic and inorganic bases (i.e., OH−, CO32−, PO43−, NH3, ClO−, diethanolamine, triethanolamine) as model compounds. The sensing system has been designed based on color-sensitive dyes (Fuchsine, Giemsa, Thionine, and CoCl2) which were used as sensor elements. The color changes of a sensor array were observed by the naked eye. The color patterns were recorded using digital imaging in a three-dimensional (red, green, and blue) space and quantitatively analyzed with color calibration techniques. Distinctive colorimetric patterns for target bases via linear discriminant analysis (LDA) and hierarchical clustering analysis (HCA) were observed. The results indicated that the analytes related to each class (at the different concentration levels in the range of 0.001–1.0 mol L−1) were clustered together in the canonical discriminant plot and HCA dendrogram with high sensitivity and an overall precision of 85%. Furthermore, the first function factor of LDA correlated with the concentration of each target analyte in a correlation coefficient (R2) range of 0.864–0.996. These described procedures based on the colorimetric sensor array technique could be a promising candidate for practical applications in package technology and facile detection of pollutants.

Development of Analytical Quality by Design RP-HPLC Method and Its Validation for Estimation of Gefitinib from Bulk, Tablet Dosage Form and Complex Nanoformulation.

Estimation of the drug and development of the method is a critical aspect of formulation development and a critical factor for analytical scientists. Gefitinib is a poorly soluble anticancer drug. The present research enlightens the topic of the development of innovative quality by design methods for the estimation of Gefitinib (GF) from bulk, pharmaceutical tablet formulation and complex nanoformulations. To simplify the estimation of poorly soluble drugs like GF, Response Surface Methodology (RSM) was adopted with effective leverages to obtain precise computation design space using the Box-Behnken Design (BBD) model. The major 3 mixed effect independent factors (Percentage of Buffer, pH of buffer and flow rate) were screened with 3 prominent dependent responses (viz., Theoretical Plate, Retention Time, and Tailing Factor) selected for optimal analysis. Furthermore, co-processed steps were employed for the estimation of the analyte from the complex formulation. The RP-HPLC method utilizes the quality by design (QbD) approach can effectively estimate the analyte concentration of less than 4.5 min. The developed method was economically robust, and sensitive and shows a % relative standard deviation (%RSD) of less than 2% for all the selected validation parameters. The estimated design space suggests the highest desirability (R2-0.998) at 60% of buffer in the mobile phase, pH 4.25, and flow rate of 0.7 mL/min. The QbD approach was used to design and develop the method by understanding the interaction between dependent and independent variables to get the optimum values. The developed method was validated successfully and can be useful for formulation scientists to estimate drug concentration and drug release profiles from complex nanoformulations. The analytical approach was designed and quantified using a quality-by-design approach to make the RP-HPLC method more robust and efficient for the estimation of analytes from complex nanoformulations. The method is also useful to eliminate the interfering molecule during estimation by employing co-processing steps. The developed method saves time, and cost of solvent and employs QbD as a requirement of recent regulatory concern.

Advances in Water Resource Management: An In Situ Sensor Solution for Monitoring High Concentrations of Chromium in the Electroplating Industry

Concerning environmental safety and mitigating the risk of water pollution, the electroplating industry, historically reliant on the use of elevated concentrations of heavy metals to achieve high-quality products, faces a crucial challenge in monitoring wastewater enriched with these metals, notorious for their adverse effects on ecosystems and human health. Chromium, in both oxidation states Cr (III) and Cr (VI), emerges as a prominently employed metal, yielding noteworthy outcomes throughout the galvanisation process. This research showcases the prototype of an automatic in situ sensor tailored to industry sustainability efforts to facilitate real-time monitoring and efficient water management. This custom sensor, characterized by sensitivity, reliability, and user-friendliness, utilizes UV-Vis colorimetric principle to detect Cr in both oxidation forms ranging from grams per litre (g/L) to parts per million (ppm). This is made possible by the unique vibrant colours induced by chromium ions, enabling the precise measurement of analyte concentrations. Thanks to 3D printing, this sensor system interacts with customized parts, designed and validated through simulation processes, for filtering out particulate that may interfere with the analysis. The outcome represents a synergistic blend of technology and environmental responsibility, aligning industrial processes with the goal of safeguarding water resources and ecosystems.

Verifying the nonreporting hemolysis index for potassium, phosphate, magnesium, AST, LDH, iron, CA 19-9, and vitamin D, using Beckman Coulter AU5800 and DxI800 automated analyzers.

Hemolysis is a common reason for nonreporting results in biochemistry and is measured using the hemolysis index (HI), with nonreporting limits set for analytes by manufacturers. To verify the nonreporting HI limit for potassium, phosphate, magnesium, aspartate aminotransferase (AST), lactate dehydrogenase (LDH), iron, CA19-9, and vitamin D on the Beckman Coulter AU5800/DxI800 analyzers. Hemolysate was created from EDTA-lined tubes of whole blood using an osmotic shock procedure. The hemolysate underwent serial dilutions with saline and was spiked in paired serum. The delta changes in HI and analyte concentration were measured, assessed using regression analysis, and compared against calculated reference change values. A linear relationship between increasing HI and increasing analyte concentration (R2> 0.9) was observed for potassium (y=0.8864x), phosphate (y=0.1079x), magnesium (y=0.0678x), AST (y=29.035x), and LDH (y=350x). Increasing HI values did not have a linear effect on iron (y=-0.2544x), CA19-9 (y=2.7019x), or vitamin D (y=8.036x) concentrations. The results from this experiment support increasing the HI nonreporting limit to 100mg/dL for potassium; 200mg/dL for magnesium; and 300mg/dL for phosphate, CA19-9, and vitamin D. The iron assay is not affected by hemolysis as high as 500mg/dL. The current HI nonreporting limit of 50mg/dL is appropriate for LDH.

Compact colorimetric method for determining formaldehyde in indoor air: Applying to an environment contaminated with hand sanitizer vapor

Hand sanitizer, widely used during the COVID-19 pandemic, must contain at least 60 % ethyl alcohol (ethanol) as an active ingredient. Due to its high vapor pressure, ethanol is rapidly transformed into vapor after the application over any surface. However, depending on the indoor air conditions, ethanol can rapidly oxidize to formaldehyde near harmful concentration levels. This study describes a simple and sensitive method to determine parts-per-billion (ppb) of gaseous formaldehyde using a cuvette (1.5 mL polystyrene, path length: 10 mm) as a microimpinger. Indoor and outdoor air was collected by the microimpinger containing 500 μL of 3-Methyl-2-benzothiazolinone hydrazone (MBTH) (2.32 × 10−3 mol L−1) at 50 mL min−1, resulting in a blue product after 30 min of sampling. Absorbance was measured at 680 nm and is proportional to the sampling period, analyte concentration, and sampling flow rate. Under the established conditions, a limit of detection of 7.0 ppb was achieved, which can be improved using longer sampling times. The analytical method was used to evaluate the oxidation of ethanol vapor by ozone in the indoor air. 10 min after the application of hand sanitizer, the air sample taken over the next 30 min revealed a notable rise in the concentration of low molecular weight aldehydes, measured as formaldehyde equivalent, within the room's air, and can reach around 100 ppb, which may be responsible for effects such as watery eyes, burning sensations in the mucous membrane, and difficulty breathing. The present technique affords a simple, inexpensive measurement with very little reagent consumption. Besides, the method is selective and highly sensitive. This method could be used either in outdoor or indoor environments.