# Upcycled Coffee Waste as Sustainable Sorbents for Monitoring Organophosphorus Pesticides in Environmental Waters

## TL;DR

This paper shows how used coffee grounds can be repurposed to detect harmful pesticides in water, offering an eco-friendly solution.

## Contribution

The study introduces upcycled coffee waste as a sustainable and effective sorbent for pesticide monitoring in environmental waters.

## Key findings

- Acid-treated spent coffee grounds were the most efficient sorbent for pesticide extraction.
- The method achieved high recoveries (85.9–109.3%) and low detection limits for organophosphorus pesticides.
- The approach aligns with green analytical chemistry principles and works well with real water samples.

## Abstract

This study presents a solid-phase extraction (SPE) method
using
upcycled coffee waste, specifically acid-treated spent coffee grounds,
as sustainable biosorbents for the LC–MS/MS determination of
malathion, disulfoton, and chlorpyrifos in environmental waters. Eight
coffee-derived materials produced through distinct chemical and thermal
pretreatments were fully characterized by FTIR, SEM, TGA, BET, and
zeta potential analyses. Acid-treated spent coffee grounds were identified
as the most efficient sorbent and subsequently optimized using a 25–1 fractional factorial design. The optimized conditions
(conditioning pH 3.0, sample pH 3.0, 25 mg of sorbent, 10 mL of sample,
and 0.5 mL of eluent) provided wide linear ranges (5.0–250.0
μg L–1 for malathion; 25.0–250.0 μg
L–1 for disulfoton and chlorpyrifos), low LOQs (5.0
μg L–1 for malathion; 25.0 μg L–1 for disulfoton and chlorpyrifos), recoveries between
85.9 and 109.3%, and precision with CV ≤15%. The method achieved
an AGREEPREP score of 0.64, indicating strong alignment with Green
Analytical Chemistry principles. Application to real surface and groundwater
samples demonstrated its suitability for detecting organophosphorus
residues, confirming the analytical performance and practical applicability
of coffee-waste-based sorbents for environmental monitoring.