Determination of glyphosate residue in maize and rice using a fast and easy method involving liquid chromatography-mass spectrometry (LC/MS/MS).

A fast and easy method was developed for the determination of glyphosate in maize and rice by using liquid chromatography triple quadrupole mass spectrometry with a Dionex Ion Pack column and phosphate buffer mobile phase. Samples were extracted with an acidified methanol solution. An isotope-labeled internal standard was added to the sample before extraction to ensure accurate tracking and quantification. The method's performance was evaluated through a series of assessments to determine the accuracy, precision, linearity, matrix effect, limit of detection (LOD), and limit of quantification (LOQ). The mean recoveries for both matrices were within 70-105% at three fortification levels, including the LOQ. The precision for replicates was <20% (RSD%) for both matrices. Good linearity (R=0.9982) was obtained over the concentration range of 0.01-1.5 mg kg. The LOD was determined to be 0.002 mg kg for rice and 0.004 mg kg for maize. The LOQ was 0.01 mg kg for both maize and rice. Due to its versatility, the proposed method could be considered useful for the determination of glyphosate in cereals in routine analysis.