Validation of a liquid chromatography ultraviolet method for determination of herbicide diuron and its metabolites in soil samples

Pollutants in aquatic system: a frontier perspective of emerging threat and strategies to solve the crisis for safe drinking water

Water is an indispensable natural resource and is the most vital substance for the existence of life on earth. However, due to anthropogenic activities, it is being polluted at an alarming rate which has led to serious concern about water shortage across the world. Moreover, toxic contaminants released into water bodies from various industrial and domestic activities negatively affect aquatic and terrestrial organisms and cause serious diseases such as cancer, renal problems, gastroenteritis, diarrhea, and nausea in humans. Therefore, water treatments that can eliminate toxins are very crucial. Unfortunately, pollution treatment remains a difficulty when four broad considerations are taken into account: effectiveness, reusability, environmental friendliness, and affordability. In this situation, protecting water from contamination or creating affordable remedial techniques has become a serious issue. Although traditional wastewater treatment technologies have existed since antiquity, they are both expensive and inefficient. Nowadays, advanced sustainable technical approaches are being created to replace traditional wastewater treatment processes. The present study reviews the sources, toxicity, and possible remediation techniques of the water contaminants.

Identification of pesticides in water samples by solid-phase extraction and liquid chromatography-electrospray ionization mass spectrometry

The Contaminants of Emerging Concern (CECs), including pesticides, have been a trending topic and Brazil is the country with the highest usage of pesticides worldwide. This study aimed to measure the presence of pesticide residues in the water from different sources in the city of Porto Alegre. We analyzed 55 samples from drinking water treatment plants, public water sites, and sewage treatment plants from winter 2018 to summer 2020 by solid-phase extraction and high-performance liquid chromatography-electrospray ionization mass spectrometry. Among 184 pesticides evaluated, 107 matched validation criteria (linearity, trueness, accuracy, repeatability, reproducibility) and 15 of them were detected in different water samples, including seven insecticides, five antifungals, and three herbicides, with a wide range of toxicity levels and noticeable seasonal differences. For the worst-case scenario evaluation, 20 out of 22 (90.9%) samples exceeded the Risk Quotient of 1. The sum of pesticide concentrations exceeded 100 ng L^-1 in 66.7% of samples in February 19 and in 75% of samples in February 20 and the total pesticide concentration has reached the worrisome mark of 1615 and 954.96 ng L^-1 respectively. Therefore, our results make evident the need to promote public policies to achieve better water quality monitoring. PRACTITIONER POINTS: Among 184 pesticides evaluated, 107 matched validation criteria (linearity, trueness, accuracy, repeatability, reproducibility). A total of 55 different water samples were analyzed, and 15 pesticides were detected and five quantified. For the worst-case scenario evaluation, 20 out of 21 samples exceeded the Risk Quotient of 1 on Feb/20. The pesticide concentrations sum exceeded 100 ng L^-1 in 66.7% of samples on February 19 and in 75% of samples on February 20. It is mandatory to improve water monitoring to guide the development of public policies concerning its quality.

Extraction of soluble sugars from green coffee beans using hot water and quantification by a chromatographic method without an organic solvent

An optimal condition for extraction of soluble sugars from green coffee using water and a validated chromatographic method for its separation and quantification were proposed in this research. An orbital incubator shaker (OIS) and microwave-assisted extraction (MAE) were the 2 techniques used to extract soluble sugars. In such experiments, the variables: sample amount (300, 400, and 500 mg), time (30, 60, and 90 min), and temperature (30, 45, and 60 °C) were tested. The separation of sugars was performed in a chromatographic system (high-performance liquid chromatography refractive index detector [HPLC-RID]), which presented the selectivity for the analytes, a limit of detection of 0.020 g/L, a limit of quantification of 0.0625 g/L, and recovery rates greater than 95%. The repeatability and inter-day precision had low dispersion, RSD < 2.0% and < 3.0%, respectively. Sucrose content ranged from 0.65 to 2.39 g/L using an OIS and from 1.19 to 2.72 g/L by MAE, while glucose and fructose concentration varied from 0.08 to 0.12 g/L using both methods. The OIS technique is preferably indicated for extraction of soluble sugars at the following conditions: 500 mg of grounded green coffee, 90 min, and 60 °C. The proposed method for soluble sugar extraction and quantification may be applied in research laboratories and food industries since it is a low-cost and environment-friendly technique.

Distribution of pesticides in agricultural and urban soils of Brazil: a critical review

The extensive use of pesticides leads to soil contamination and is harmful to environmental health. Brazil is considered the world's largest consumer of pesticides; however, there is no published review of the distribution and concentration of pesticides in the Brazilian soils. Thus, the objective of this study was to analyze the occurrence of pesticide residues in Brazilian soils through a systematic review of the data obtained from the official records of government agencies and scientific literature. Further, this review aims to estimate the risk quotient using the data extracted from these studies and compare it with the values from current legislation. The studies on pesticides were selected and screened, out of which 21 scientific articles were included in this review. The studies highlighted that 55 pesticides were detected in the soils in Brazil. Of these, 58% belonged to the chemical class of organochlorines and their concentration ranged from 0.0002-1243.68 mg kg-1. DDT (0.00002-1243.68 mg kg-1), HCH (0.00007-962.00 mg kg-1) and diuron (0.0031-4.16 mg kg-1) contributed to highest pesticide concentrations in soil. Residential soils had higher pesticide concentrations and greater risk factors than the agricultural soils. Moreover, 20% of the studies detected mixtures containing more than 10 types of pesticides. This study concluded that the specific scenarios evaluated by the reviewed studies do not reflect the current pesticide use and contamination in Brazil and there is a need for more information related to pesticide contamination in soils.

Organic Analysis of Environmental Samples Using Liquid Chromatography with Diode Array and Fluorescence Detectors: An Overview

This overview is focused to provide an useful guide of the families of organic pollutants that can be determined by liquid chromatography operating in reverse phase and ultraviolet/fluorescence detection. Eight families have been classified as the main groups to be considered: carbonyls, carboxyls, aromatics, phenols, phthalates, isocyanates, pesticides and emerging. The references have been selected based on analytical methods used in the environmental field, including both the well-established procedures and those more recently developed.