MSPD sample preparation approach for reversed-phase liquid chromatographic analysis of pesticide residues in stem of coconut palm

Greener production of a starch-based nanohybrid material (core-shell) for the simultaneous extraction of persistent organic pollutants in shrimp samples

Here, a novel nanohybrid material (Ag@CD@ANS) based on oat starch was produced, characterized, and applied to extract persistent organic pollutants in a shrimp sample. By the characterization experiments, Ag@CD@ANS was successfully synthesized. The functionalization of the material by 1,2-naphthoquinone-4-sulphonic acid (ANS) was confirmed using the infrared technique and CHN elemental analysis. The isotherm study showed that the material has a high adsorption capacity for the pesticides of interest (flutriafol, atrazine, heptachlor, DDT and bifenthrin) allowing their extraction from shrimp samples. The optimal condition for extraction was obtained using multivariate analysis. The nature of the elution solvent (hexane, methanol, acetonitrile) and the mass ratio between sample:adsorbent (1:1; 1:5 and 1:10) were the evaluated factors for extraction using Ag@CD@ANS and commercial adsorbents (neutral alumina, octadecyl, silica gel). From the multivariate analysis, it was observed that the optimal condition for pesticide extraction using Ag@CD@ANS was reached, using a 1:5 ratio (sample:adsorbent) and acetonitrile (10 mL) as elution solvent. For the commercial adsorbents, the optimal condition for pesticide extraction was reached, using a 1:3 ratio (sample:adsorbent), acetonitrile (10 mL) and neutral alumina as commercial adsorbent. Ag@CD@ANS efficiency was compared with an optimal commercial adsorbent (neutral alumina). No significant difference (p < 0.05) between neutral alumina and Ag@CD@ANS was observed. Recoveries ranging from 75 to 105 % with coefficients of variation ≤ 15 % (n = 3) were obtained using neutral alumina while using Ag@CD@ANS, recoveries ranging from 73 to 102 %, with coefficient of variation ≤ 13 % (n = 3) were obtained for the target pesticides. Limits of detection ranging from 0.5 to 1.0 µg Kg-1 and limits of quantification ranging from 1.6 to 3.3 µg Kg-1 were reached. The results demonstrated that Ag@CD@ANS can alternatively be used as a support for the extraction of persistent organic pollutants, having the advantage of being reusable for up to three cycles.

A Comprehensive Review of Pesticide Residues in Peppers

Pesticides are chemicals that are used to control pests such as insects, fungi, and weeds. Pesticide residues can remain on crops after application. Peppers are popular and versatile foods that are valued for their flavor, nutrition, and medicinal properties. The consumption of raw or fresh peppers (bell and chili) can have important health benefits due to their high levels of vitamins, minerals, and antioxidants. Therefore, it is crucial to consider factors such as pesticide use and preparation methods to fully realize these benefits. Ensuring that the levels of pesticide residues in peppers are not harmful to human health requires rigorous and continuous monitoring. Several analytical methods, such as gas chromatography (GC), liquid chromatography (LC), mass spectrometry (MS), infrared spectroscopy (IR), ultraviolet-visible spectroscopy (UV-Vis), and nuclear magnetic resonance spectroscopy (NMR), can detect and quantify pesticide residues in peppers. The choice of analytical method depends on the specific pesticide, that is being tested for and the type of sample being analyzed. The sample preparation method usually involves several processes. This includes extraction, which is used to separate the pesticides from the pepper matrix, and cleanup, which removes any interfering substances that could affect the accuracy of the analysis. Regulatory agencies or food safety organizations typically monitor pesticide residues in peppers by stipulating maximum residue limits (MRLs). Herein, we discuss various sample preparation, cleanup, and analytical techniques, as well as the dissipation patterns and application of monitoring strategies for analyzing pesticides in peppers to help safeguard against potential human health risks. From the authors' perspective, several challenges and limitations exist in the analytical approach to monitoring pesticide residues in peppers. These include the complexity of the matrix, the limited sensitivity of some analytical methods, cost and time, a lack of standard methods, and limited sample size. Furthermore, developing new analytical methods, using machine learning and artificial intelligence, promoting sustainable and organic growing practices, improving sample preparation methods, and increasing standardization could assist efficiently in analyzing pesticide residues in peppers.

Quantitative determination of targeted and untargeted pesticide residues in coconut milk by liquid chromatography - Atmospheric pressure chemical ionization - high energy collisional dissociation tandem high-resolution mass spectrometry

Quantitative determination of targeted and untargeted pesticide residues from food products is very important for the assessment of safety of the food products. In the present work, a simple, selective and sensitive method based on liquid chromatography atmospheric pressure chemical ionization high energy collisional dissociation high-resolution tandem mass spectrometry (LC-APCI-HCD-HRMS/MS) for quantification of 19 priority organophosphorus and carbamate pesticides and 10 untargeted pesticides from coconut milk samples was developed and validated. The pesticide residues were extracted by solvent partition followed by dispersive solid-phase extraction clean-up and quantified by LC-APCI-HRMS/MS technique. The method showed the linearity for targeted pesticides in the range of 0.5-1000 ng/g with a limit of detection of ranging 0.5-5 ng/g and limit of quantification of ranging 1-10 ng/g measured at 3:1 and 10:1 signal to noise ratios, respectively. The untargeted pesticide residues were quantified by the response factor method. The method was validated for intraday and interday precision, which was less than 15%. The recovery of the analytes varied between 82 and 117%, and the developed method was applied for the analysis of the coconut milk samples. The analyzed samples showed the presence of quinalphos, malathion, and methiocarb at concentrations of 4.55, 5.54, and 206.99 ng/g.