Reliable Determination Research Articles

At second glance: The importance of strict quality control – A case study on microplastic in the Southern Ocean key species Antarctic krill, Euphausia superba

The stomach content of 60 krill specimens from the Southern Ocean were analyzed for the presence of microplastic (MP), by testing different sample volumes, extraction approaches, and applying hyperspectral imaging Fourier-transform infrared spectroscopy (μFTIR). Strict quality control was applied on the generated results. A high load of residual materials in pooled samples hampered the analysis and avoided a reliable determination of putative MP particles. Individual krill stomachs displayed reliable results, however, only after re-treating the samples with hydrogen peroxide. Before this treatment, lipid rich residues of krill resulted in false assignments of polymer categories and hence, false high MP particle numbers. Finally, MP was identified in 4 stomachs out of 60, with only one MP particle per stomach. Our study highlights the importance of strict quality control to verify results before coming to a final decision on MP contamination in the environment to aid the establishment of suitable internationally standardized protocols for sampling and analysis of MP in organisms including their habitats in Southern Ocean and worldwide.

Are multiple coders needed for cause of death assignment: results from telephonic verbal autopsy interviews conducted in 2021 in South Africa.

Verbal autopsy (VA) methods have emerged to estimate causes of death in populations lacking robust civil registration and vital statistics (CRVS) systems. Despite World Health Organization endorsement of routine VA use, cost and efficiency concerns persist. Telephonic verbal autopsies (teleVAs) can reduce cost. Physician coding offers a valuable approach, but the expertise required makes it resource-intensive, often involving multiple coders for consensus. To assess inter-coder agreement for cause of death (CoD) in South African teleVAs using Kappa statistics, evaluating if agreement surpasses a 0.8 cut-off (very high) potentially allowing single coders. A cross-sectional study employed telephonic VA interviews on non-facility deaths in Cape Town (December 2020-September 2021). Trained fieldworkers administered a standard VA questionnaire. Each case's VA responses were reviewed independently by two physicians, medically certifying the CoD. A panel was used to solve disagreements. Cohen's kappa-statistic (k-statistic) tested agreement levels. Decedents were aged between 18 and 98 years. In total, 228 teleVAs (16.6% response rate) were conducted. Physician coding agreement was good overall (k-statistic: 0.63). Diabetes mellitus (47%) and other non-communicable disease (42%) had initial agreement between physician coders in less than 50% of cases in comparison to consensus totals. COVID-19 (89%) and acute cardiac disease (83%) showed initial agreement in more than 80% of cases compared to consensus totals. A chi-square test revealed a significant difference in the number of causes listed on death notification forms for cases with and without agreement in Part 1 (χ2 = 14.71, p < 0.01), but not in Part 2 (χ2 = 4.97, p = 0.17). CoD agreement might not be high enough to infer that single coders can be used instead of multiple coders. Challenges with co-morbidities and specific CoDs with multiple sequelae highlight the need for further research and refinement of VA methodologies for reliable CoD determination in routine practice.

Wykorzystanie ilościowych wskaźników form strukturalnych do geologicznego i statystycznego modelowania struktur o złożonej budowie

Computer processing of geological data is widely used to process geological information. Therefore, an assessment of the structures as potential reservoir traps for oil and gas was carried out on the basis of quantitative parameter analysis. This approach made it possible to reasonably confirm certain regularities. To identify these regularities in the relationships between the numerical parameters of complex structures, computer geological and statistical modeling of the studied objects of the Boryslav-Pokuttya zone was carried out using correlation and cluster analysis. In general, correlation analysis allows analyzing the set of determined values and is aimed at identifying and studying the systems that form some values included in this set. Classification of any objects by meaningful groups is carried out by the method of cluster analysis. To model the processes that formed local structures and to determine the patterns of their spread, a large volume of quantitative indicators was processed. On the basis of quantitative indicators, it was possible to evaluate the results of studies of the tectonic stresses and deformations distribution, which will contribute to more reliable determination of reservoir potential for oil and gas. In turn, this will significantly increase the geological effectiveness of oil and gas exploration in the Boryslav-Pokuttya area. The contemporary form of structures and their spatial arrangement result from the long-termimpact of tectonic forces over geological time. Different manifestations of tectonic activity in successive geological epochs leads to specific changes in the structural plan of geological formations, influencing the potential oil and gas content within them (formation, unforming, and re-forming of traps and, accordingly, hydrocarbon reservoirs). The structures of the Boryslav-Pokuttya zone have undergone a complex and lengthy formation process: from the formation of flysch folds to very complex structural forms. This complexity is contributed to the influence of the magnitude and nature of the tectonic forces. The morphological diversity of the structures, can be described by numerical parameters, which can be used as a basis for classifying these structures in the Boryslav-Pokuttya zone.

Selective determination of an ovarian cancer biomarker at low concentrations with surface imprinted nanotube based chemosensor

In this study, an electrochemical chemosensor that utilizes a conductive polymer-based molecularly imprinted polymer (MIP) surface for rapid and reliable determination of CA125 was devised. A novel method has been applied to fabricate CA125 imprinted polypyrrole nanotubes (MI-PPy NT) via vapor deposition polymerization (VDP) as a recognition element for highly selective and sensitive determination of CA125. The chemosensor was prepared by immobilizing MI-PPy NT onto screen-printed gold electrodes (Au-SPE) and the performance of the sensor was evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in terms of selectivity, sensitivity, linear dynamic concentration range (LDR) and limit of detection (LOD). The MI-PPy NT@Au-SPE sensor exhibited high sensitivity (68.57 μA per decade) to the CA125 concentration ranging from 0.1 U mL−1 to 100 U mL−1 at an LOD of 0.4 U mL−1 with a correlation coefficient of 0.9922. The developed chemosensors with their novel design combined with a facile fabrication method, prove to be promising as future state-of-the-art biosensors.

Adequate cefazolin therapy for critically ill patients: can we predict active concentrations from given protein-binding data?

Abstract Objectives Therapeutic drug monitoring of β-lactam antibiotics has become an important tool for treatment of severe infections, especially for critically ill patients who often exhibit altered PK/PD. Therapeutic targets are based on MIC, which refers to the active concentration of the drug. Cefazolin, a β-lactam agent used for treating of MSSA bacteraemia, has a protein binding of approximately 80 %. Therefore, a reliable determination of the active, non-protein-bound concentration is required to ensure optimal therapeutic outcome. Methods From seven critically ill patients who received an initial dose of 2 g cefazolin, followed by a continuous 24 h infusion, a total of 24 serum samples were obtained. The non-protein-bound concentration was directly measured after ultrafiltration and compared to prediction based total concentrations and protein binding values from the literature. For the analysis, a rapid and reliable LC-MS3 based assay was established, offering maximum sensitivity and specificity. Results The measured non-protein-bound concentration varied over a wide range (7.6–118 mg/L), with 22 out of 24 samples exhibiting cefazolin levels above the therapeutic target values (8–16 mg/L). Additionally, the observed protein binding ranged from 29 to 78 % (median 66.8 %), which was significantly lower than that reported in the literature. When comparing the measurements to the predictive performance of total concentrations and protein binding values, poor results were obtained. Conclusions The results show a high variability in plasma protein binding of cefazolin in critically ill patients. Therefore, the “one-dose-fits-all” principle can no longer be considered up to date. For personalised cefazolin therapy based on therapeutic drug monitoring (TDM) it is recommended to determine the active, non-protein-bound drug concentration, as calculations from the total fraction yield poor results.

SPH simulation of shock-induced chemical reactions in reactive powder mixtures

Reactive materials (RMs) are a mixture of two or more nonexplosive solid components in which, under extreme conditions, self-sustaining chemical reactions occur with the release of a high amount of energy. Knowing the kinetics of chemical reactions in RMs plays the key role in their efficient applications. In this work, we propose a macroscopic mathematical model of shock-induced chemical reactions based on smoothed particle hydrodynamics (SPH) for particle-scale simulation. The model includes the elastic-plastic deformation of materials, heating due to deformation and chemical reactions, diffusion of components, and heat transfer. The test calculations performed for the zero- and first-order reactions in the Al/S mixture showed a need for a more reliable determination of criteria and constants of chemical reactions. For this purpose, we propose a schematic experimental arrangement for the experimental and theoretical determination of the critical reaction pressure and the rate constant of the reaction. The type and corresponding constants of chemical reactions can be determined, for example, by the maximum likelihood method. We theoretically determined the zones of chemical reaction with different modes and found the influence of the projectile velocity and the intensity of shock waves on the development and completion of chemical reactions.

Volatile organic compounds in headspace characterize isolated bacterial strains independent of growth medium or antibiotic sensitivity.

Early and reliable determination of bacterial strain specificity and antibiotic resistance is critical to improve sepsis treatment. Previous research demonstrated the potential of headspace analysis of volatile organic compounds (VOCs) to differentiate between various microorganisms associated with pulmonary infections in vitro. This study evaluates whether VOC analysis can also discriminate antibiotic sensitive from resistant bacterial strains when cultured on varying growth media. Both antibiotic-sensitive and -resistant strains of Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumonia were cultured on 4 different growth media, i.e. Brain Heart Infusion, Marine Broth, Müller-Hinton and Trypticase Soy Agar. After overnight incubation at 37°C, the headspace air of the cultures was collected on stainless steel desorption tubes and analyzed by gas chromatography time-of-flight mass spectrometry (GC-tof-MS). Statistical analysis was performed using regularized multivariate analysis of variance and cross validation. The three bacterial species could be correctly recognized based on the differential presence of 14 VOCs (p<0.001). This discrimination was not influenced by the different growth media. Interestingly, a clear discrimination could be made between the antibiotic-resistant and -sensitive variant of Pseudomonas aeruginosa (p<0.001) based on their species-specific VOC signature. This study demonstrates that isolated microorganisms, including antibiotic-sensitive and -resistant strains of Pseudomonas aeruginosa, could be identified based on their excreted VOCs independent of the applied growth media. These findings suggest that the discriminating volatiles are associated with the microorganisms themselves rather than with their growth medium. This study exemplifies the potential of VOC analysis as diagnostic tool in medical microbiology. However, validation of our results in appropriate in vivo models is critical to improve translation of breath analysis to clinical applications.

Electrosynthesis of toluidine blue on Fe3O4 nanoparticles modified electrodes in a deep eutectic solvent for the electrochemical determination of neurotransmitter epinephrine

The electrochemical methodology is important and challenging for rapid, simple, low-cost, sensitive, selective and reliable determination of biomolecules to diagnose and treat diseases. Our work presents the combination of the catalytic ability of a toluidine blue (TB) redox polymer and the important physical and chemical properties of Fe3O4 nanoparticles (Fe3O4NPs) to develop a new disposable sensor with advanced analytical performancecharacteristics for the determination of EP. Fe3O4NPs combined with poly(toluidine blue) (PTB) redox polymer film on a PGE support have been developed involving electropolymerization of TB in deep eutectic solvents (DES), which is a green solvent. Scanning electron microscopy (SEM) was used to evaluate the effect of the electrode composition on the surface morphology of the nanostructured PTB films, being correlated with the electrochemical characteristics observed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). It has been shown that combining Fe3O4NPs with PTB synthesized in DES improves the analytical properties of the sensor more than using each modifier individually due to synergistic effects. The analytical performance of PTBethaline-HCl/Fe3O4/PGE was evaluated for epinephrine (EP) reduction in the presence of an excess dopamine (DA) by DPV. The proposed sensor was used to determine EP using the reduction peak as a voltammetric signal instead of the oxidation peak usually employed to minimize possible interfering effects in biological samples. The developed sensor showed good response with high sensitivity (9.26 µA µM−1 cm−2), low detection limit (0.05 µM), wide linear range (0.19–20 µM), and excellent reproducibility (RSD 1.7 %) and repeatability (RSD 2.9 %). The practical applicability of the proposed sensor has been successfully tested for the quantification of EP in human serum and injection ampoule samples. This is a very promising analytical method for monitoring the level of EP in real samples.

Revealing the Bonding Nature and Electronic Structure of Early-Transition-Metal Dihydrides

Metal hydrides are potential candidates for applications in hydrogen-related technologies, such as energy storage, hydrogen compression, and hydrogen sensing, to name just a few. However, understanding the electronic structure and chemical environment of hydrogen within them remains a key challenge. This work presents a new analytical pathway to explore these aspects in technologically relevant systems using hard x-ray photoelectron spectroscopy (HAXPES) on thin films of two prototypical metal dihydrides: YH2−δ and TiH2−δ. By taking advantage of the tunability of synchrotron radiation, a nondestructive depth profile of the chemical states is obtained using core-level spectra. Combining experimental valence-band (VB) spectra collected at varying photon energies with theoretical insights from density functional theory (DFT) calculations, a description of the bonding nature and the role of d versus sp contributions to states near the Fermi energy are provided. Moreover, a reliable determination of the enthalpy of formation is proposed by using experimental values of the energy position of metal s-band features close to the Fermi energy in the HAXPES VB spectra. Published by the American Physical Society 2024

Investigations on eddy current sensors regarding inline-capability of zinc coating monitoring using a model-based estimator

This work deals with preliminary investigations for the reliable thickness determination of a conductive, nonmagnetic metal coating on ferromagnetic steels. For this purpose, an eddy current sensor system is used. Different analytical coil models are compared: a normal solenoid, a differential coil and a rectangular coil. Thus, a sensitivity analysis regarding interfering influences, e.g., liftoff fluctuations, is done. Based on this, the advantages and disadvantages of the analyzed coil geometries are discussed. Finally, an model-based estimator is used to determine the coating thickness from simulation data at different operating points.

Live cell fluorescence microscopy-an end-to-end workflow for high-throughput image and data analysis.

Fluorescence microscopy images of biological samples contain valuable information but require rigorous analysis for accurate and reliable determination of changes in protein localization, fluorescence intensity, and morphology of the studied objects. Traditionally, cells for microscopy are immobilized using chemicals, which can introduce stress. Analysis often focuses only on colocalization and involves manual segmentation and measurement, which are time-consuming and can introduce bias. Our new workflow addresses these issues by gently immobilizing cells using a small agarose block on a microscope coverslip. This approach is suitable for cell-walled cells (yeast, fungi, plants, bacteria), facilitates their live imaging under conditions close to their natural environment and enables the addition of chemicals during time-lapse experiments. The primary focus of the protocol is on the presented analysis workflow, which is applicable to virtually any cell type-we describe cell segmentation using the Cellpose software followed by automated analysis of a multitude of parameters using custom-written Fiji (ImageJ) macros. The results can be easily processed using the provided R markdown scripts or available graphing software. Our method facilitates unbiased batch analysis of large datasets, improving the efficiency and accuracy of fluorescence microscopy research. The reported sample preparation protocol and Fiji macros were used in our recent publications: Microbiol Spectr (2022), DOI: 10.1128/spectrum.01961-22; Microbiol Spectr (2022), DOI: 10.1128/spectrum.02489-22; J Cell Sci (2023), DOI: 10.1242/jcs.260554.

A SERS aptasensor based on HCR mediated signal conversion strategy for the rapid and reliable determination of Escherichia coli O157:H7

Rapid and reliable determination of pathogenic bacteria is crucial for food safety and public health. Surface-enhanced Raman spectroscopy (SERS) based aptasensors have attracted increasing attention in the determination of pathogenic bacteria due to their high specificity and sensitivity. However, the sensitivity and reliability of the SERS aptasensors for the determination of pathogens were hindered by the uneven distribution of SERS tags. To tackle this limitation, a SERS aptasensor based on a hybridization chain reaction (HCR) mediated signal conversion strategy was fabricated for the determination of E. coli O157:H7. In the presence of E. coli O157:H7, the blocked aptamer specifically binds with it and releases the blocker DNA. Then the blocker DNA hybridizes with the capture DNA on the SERS probe and initiates the HCR reaction, which further leads to the formation of double stranded DNA and the reduction of the SERS signal intensity of 4-mercaptobenzonitrile (4-MBN). Under the optimal conditions, the SERS signal intensity at 1073.9 cm−1 and the logarithmic value of the concentration of E. coli O157:H7 in the range of 8 × 102–8 × 107 CFU·mL−1 exhibited a good linear relationship, with a coefficient of determination of 0.92. The limit of detection for E. coli O157:H7 was 409 CFU·mL−1. Besides, this aptasensor exhibited satisfactory specificity for E. coli O157:H7. In addition, it showed excellent stability in real sample analysis with relative standard deviations (RSDs) below 3.76 % (n = 3). The established SERS aptasensor employed a HCR mediated signal conversion strategy and overcame the drawback of unevenly distribution of SERS tags in classical SERS aptasensors for the determination of pathogenic bacteria. This study offered a new reference for the rapid and reliable detection of pathogens with a portable Raman spectrometer.

Mitochondrial point heteroplasmy: insights from deep-sequencing of human replicate samples

BackgroundHuman mitochondrial heteroplasmy is an extensively investigated phenomenon in the context of medical diagnostics, forensic identification and molecular evolution. However, technical limitations of high-throughput sequencing hinder reliable determination of point heteroplasmies (PHPs) with minor allele frequencies (MAFs) within the noise threshold.ResultsTo investigate the PHP landscape at an MAF threshold down to 0.1%, we sequenced whole mitochondrial genomes at approximately 7.700x coverage, in multiple technical and biological replicates of longitudinal blood and buccal swab samples from 11 human donors (159 libraries in total). The results obtained by two independent sequencing platforms and bioinformatics pipelines indicate distinctive PHP patterns below and above the 1% MAF cut-off. We found a high inter-individual prevalence of low-level PHPs (MAF < 1%) at polymorphic positions of the mitochondrial DNA control region (CR), their tissue preference, and a tissue-specific minor allele linkage. We also established the position-dependent potential of minor allele expansion in PHPs, and short-term PHP instability in a mitotically active tissue. We demonstrate that the increase in sensitivity of PHP detection to minor allele frequencies below 1% within a robust experimental and analytical pipeline, provides new information with potential applicative value.ConclusionsOur findings reliably show different mutational loads between tissues at sub-1% allele frequencies, which may serve as an informative medical biomarker of time-dependent, tissue-specific mutational burden, or help discriminate forensically relevant tissues in a single person, close maternal relatives or unrelated individuals of similar phylogenetic background.

Macro-indentation testing of soft biological materials and assessment of hyper-elastic material models from inverse finite element analysis

Mechanical characterization of hydrogels and ultra-soft tissues is a challenging task both from an experimental and material parameter estimation perspective because they are much softer than many biological materials, ceramics, or polymers. The elastic modulus of such materials is within the 1 - 100 kPa range, behaving as a hyperelastic solid with strain hardening capability at large strains. In the current study, indentation experiments have been performed on agarose hydrogels, bovine liver, and bovine lymph node specimens. This work reports on the reliable determination of the elastic modulus by indentation experiments carried out at the macro-scale (mm) using a spherical indenter. However, parameter identification of the hyperelastic material properties usually requires an inverse finite element analysis due to the lack of an analytical contact model of the indentation test. Hence a comprehensive study on the spherical indentation of hyperelastic soft materials is carried out through robust computational analysis. Neo-Hookean and first-order Ogden hyperelastic material models were found to be most suitable. A case study on known anisotropic hyperelastic material showed the inability of the inverse finite element method to uniquely identify the whole material parameter set.

Numerical analysis of the porous structure of spherical activated carbons obtained from ion-exchange resins

This paper presents the results of an analysis of the porous structure of spherical activated carbons obtained from cation-exchange resin beads subjected to ion exchange prior to activation. The study investigated the effects of the type of cation exchange resin, the concentration of potassium cations in the resin beads and the temperature of the activation process on the adsorption properties of the resulting spherical activated carbons. The numerical clustering-based adsorption analysis method and the quenched solid density functional theory were used to analyse the porous structure of spherical activated carbons. Based on original calculations and unique analyses, complex relationships between preparation conditions and the porous structure properties of the obtained spherical activated carbons were demonstrated. The results of the study indicated the need for simultaneous analyses using advanced methods for the analysis of porous structures, i.e., the numerical clustering-based adsorption analysis method and the quenched solid density functional theory. This approach allows a reliable and precise determination of the adsorption properties of the materials analysed, including, among other things, surface heterogeneities, and thus an appropriate selection of production conditions to obtain materials with the expected adsorption properties required for a given industrial process.

Do GC/MS methods available for furan and alkylfurans in food provide comparable results? – An interlaboratory study and safety assessment of 2-pentylfuran in food

A call for data on the occurrence of alkylfurans in food and feed from EFSA triggered the development of new methods to cover next to furan also 2- and 3-methylfuran, 2,5-dimethyl- and 2-ethylfuran as well as 2-pentylfuran. A significant variability was noticed when comparing analysis of 2-pentylfuran and furans in the same matrix performed by different laboratories. To assess the variability an interlaboratory study including eight laboratories was organised. The highest variabilities were observed when analysing cereals, with measurements of 2-pentylfuran indicating concentrations from 8 mg/kg up to more than 1000 mg/kg in the same sample. This study illustrates that the analysis of 2-pentylfuran requires special attention, and that additional method development would be necessary to ensure reliable and reproducible determination of 2-pentylfuran at contamination level. Moreover, a recent evaluation of the EFSA Panel on Food Additives and Flavourings indicates that concerns for genotoxicity, reason why it was grouped with the shorter alkylfurans, are now ruled out. We question the need and justification to include 2-pentylfuran in the analytical method as requested by EFSA, from both the analytical and the safety perspective.

СЕЛЕКТИВНІ РИЗИКИ ВКЛАДНИКІВ ВІТЧИЗНЯНИХ БАНКІВ В УМОВАХ ВОЄННОГО СТАНУ

The article examines the essence and types of selective risks of bank depositors and their features in the conditions of martial state. The main types of selective risks of bank depositors are characterized. The expediency of improving the determination of the rating of banks when determining the risk of incorrect bank selection is substantiated. An approach to improving the determination of the rating of financial stability of banks by normalizing financial indicators taking into account their normative values is proposed. It has been established that an important factor in the depositor's determination of the bank's reliability in nowadays conditions is the level of its technologies. The essence of the risk of incorrect choice of the deposit currency by the depositor is determined and a method of its assessment based on the application of Value at Risk measurement technology is proposed. It has been established that the main source of risk of incorrect choice of deposit currency by the depositor is the level of devaluation or revaluation of the national currency during the deposit period. The expediency of using Value at Risk technology to assess this risk is substantiated. It has been established that in the conditions of martial state and increased turbulence of the foreign exchange market, it is advisable to assess the risk of incorrect choice of the deposit currency taking into account both the volatility and the trends in the exchange rates. The essence of the risk of the wrong choice of the term of the deposit is determined and the complexity of its assessment in the conditions of martial state is substantiated. Attention is focused on the importance of effectively managing the risk of the wrong choice of the type of deposit in the conditions of martial state by forming a so-called financial security cushion in the form of placing a certain amount of funds on demand deposits or time deposits with the right of early withdrawal. The necessity of developing a strategy for forming the optimal portfolio of a bank depositor in the conditions of martial state is substantiated, which can become the subject of further scientific researches.

A chemically functionalized glass support for gold and silver metallic nanoparticle analysis with LIBS

For the first time ever, the LIBS technique has been applied for the metal nanoparticle analysis, using a novel custom-designed silane-functionalized sample support for LIBS-based metallic nanoparticle analysis.

Single reaction chamber microwave digestion coupled with ICP-MS for the determination of ultra-trace mercury in rocks.

In this study, a method for rock digestion using a single reaction chamber (SRC) microwave system was established. Nitric acid (HNO3) and hydrofluoric acid (HF) were used as digestion agents, and the determination of mercury (Hg) in rocks was performed by inductively coupled plasma mass spectrometry (ICP-MS). The optimal conditions for the SRC microwave system were achieved at 260 °C and 70 bar, with a mixture of 3 mL of 65-68 wt% HNO3 and 1 mL of 49 wt% HF when the sample weight is in the range of 0.025-0.05 g. The method quantitation limit (MQL) was determined to be 0.0016 mg kg-1. Measurement accuracy was evaluated using five Chinese nationally certified reference materials, demonstrating good consistency between measurement results and certified values. The method was applied to two rock samples, resulting in a recovery rate ranging from 105% to 109%. This method exhibits high sensitivity, stability, and low acid consumption. Importantly, it provides a reliable and efficient determination method for Hg in rocks, which is of great significance in geochemical analysis.

A Comparative Study of Spectrophotometric Determination of Malathion With Ammonium Meta Vanadate and Potassium Bromate

Malathion is one of the commonly used pesticides in India which is toxic as per the World Health Organization. Its residue has been found in industrial effluent, water streams, and agricultural products. Various analytical methods such as gas chromatography, infrared spectroscopy, and thin‐layer chromatography were used for identifying the concentration of pesticides in aqueous phase. Though gas chromatography is one of the best available techniques in pesticide analysis, it involves higher cost. In this study, simple spectrophotometric methods for identifying the malathion in aqueous phase are experimented and compared using UV visible double beam spectrophotometer. Comparing these two methods will help us to select the most suitable method for specific analytical needs, considering factors such as accuracy, sensitivity, ease of use, and safety. This comparative analysis aids in choosing the best method for reliable and efficient determination of malathion. A regression analysis of Beers–Lambert plots showed a good correlation in the concentration range of 0.5–15 mg/L for the abovementioned two spectrophotometrical methods. The results showed that potassium bromate exhibits rapid, stable color complex and linearity in absorbance versus concentration study when compared with ammonium meta vanadate.