SOUTHERN JOURNAL OF SCIENCES

Background: Determining chlorine in water ensures safety. Among other methods, the DPD colorimetric method is used. The DPD Method relies on colorimetric reactions to measure free and total chlorine concentration in water samples with pink compound formation. Aims: To perform a comparative chlorine analysis using DPD, assessing reagents from 3 makers and 2 Hach instruments to identify disparities and propose adjustments for more accurate measurements. Methods: Hach High-Range and Low-Range Free chlorine determination procedures were followed. DR300 and POCKET Colorimeter II spectrophotometers were used. Tests were conducted for each DPD manufacturer in low/high ranges and in two HACH devices to determine the chlorine concentrations. Hach was used as the reference; LaMotte and PoliControl compared against it. Statistical analyses were compiled using MS Excel. Results: The tests findings were gathered in Tables 1-5. JavaScript and HTML scripts were created to convert LaMotte and PoliControl outcomes into values equivalent to those of HACH through linear interpolation. Discussion: Various DPD reagents and equipment provided slightly different readings, prompting empirical evaluation of these differences. Adjusting the results to Hach's results was selected as both the reagent and spectrophotometer were from the same brand. Differences in spectrophotometer readings were more pronounced in high-range tests nearing the upper limit of the test. Conclusions: Equipment variations caused minor result differences; DPD reagents are not interchangeable without correlation. The Open-source code developed aided in reducing reading disparities.

Background: Dr. Miguel Fornes is a researcher at CONICET and director of the Andrological Research Laboratory of Mendoza, Argentina. His research focuses on how dietary fat excess and hypercholesterolemia affect sperm physiology and male fertility. Objectives: The primary objective of Dr. Fornes' research is to investigate the effects of a high-fat diet on sperm function, capacitation, acrosomal reaction, and fertilization. He aims to develop translational animal models to study these effects without using human subjects. Methods: Dr. Fornes and his team use rabbit models to induce hypercholesterolemia through a high-fat diet. They then study the physiology and function of sperm cells from these hypercholesterolemic rabbits. Key parameters analyzed include cholesterol content in sperm membranes, ability to undergo capacitation and acrosomal reaction, and fertilization capability. Results: The studies revealed that hypercholesterolemia caused by a high-fat diet leads to increased cholesterol levels in sperm. This interferes with the normal physiology of sperm cells. In particular, many sperm from hypercholesterolemic rabbits were unable to properly undergo the acrosomal reaction, a crucial step for successful fertilization of the oocyte. This suggests high-fat diets could contribute to male infertility. Conclusions: The research highlights the importance of diet and lifestyle on male reproductive health. Dr. Fornes recommends a balanced diet like the Mediterranean diet, rich in fruits, vegetables, and olive oil, to maintain healthy sperm function and fertility. Replacing animal fats with olive oil may help prevent hypercholesterolemia-related infertility. The findings have implications for dietary guidelines and clinical interventions to support male fertility.

Introduction: The detection of methanol in alcoholic beverages represents a critical public health issue, particularly in light of the recent outbreak of poisonings in Brazil, which registered 58 confirmed cases and 15 deaths through October 2025. Methanol's toxicity, with an estimated lethal dose ranging from 0.5 to 1.5 g/kg, requires reliable analytical methods for health surveillance. Brazilian legislation establishes a maximum limit of 20 mg/100 mL of anhydrous alcohol; however, the need for accessible screening methods in field settings remains an important challenge. Objective: To critically compare three analytical methods for methanol determination: classical qualitative methods (Lucas Test and dichromate/Schiff), Brazilian colorimetric method, and gas chromatography with flame ionization detector (GC-FID), evaluating their performance and applicability in resource-limited contexts. Methods: Theoretical-comparative approach through critical analysis of specialized literature and normative technical documentation. Methods were evaluated according to: operational principle, sensitivity (LOD/LOQ), selectivity, operational complexity, analysis time, and practical applicability. Results: The Lucas Test is not applicable for methanol detection. Colorimetric methods showed moderate sensitivity (LOD ~20-160 mg/100 mL), a 10-30-minute execution time, low operational complexity, and excellent portability. The Brazilian method presented chemical equivalence with international standards, differing only in the type of reading performed. GC-FID has shown superior sensitivity (LOD ≤ 1 mg/100 mL) and high specificity, but it requires extended time (~45-60 minutes), complex laboratory infrastructure, and specialized operators. Sugars interfere with colorimetric methods. Conclusions: The methods are complementary within a hierarchical system. Colorimetric methods enable rapid field screening, while GC-FID serves as the confirmatory method for forensic analyses. We recommend implementing integrated protocols that combine in situ colorimetric screening with GC-FID confirmation in accredited laboratories for effective health surveillance.