Detection of three herbicide, and one metabolite, residues in brown rice and rice straw using various versions of the QuEChERS method and liquid chromatography-tandem mass spectrometry. (1st November 2016)

• Record Type: Journal Article
• Authors: Lee, Young-Jun; Rahman, Md. Musfiqur; Abd El-Aty, A.M.; Choi, Jeong-Heui; Chung, Hyung Suk; Kim, Sung-Woo; Abdel-Aty, Azza M.; Shin, Ho-Chul; Shim, Jae-Han
• Is Part Of: Food chemistry. Volume 210(2016)
• Page Start: 442
• Page End: 450
• Publication Date: 2016-11-01
• Subjects: Herbicides -- Rice -- Rice straw -- QuEChERS -- LC/MS/MS -- Residues; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2016.05.005
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Three herbicides and one metabolite were determined in rice and rice straw. Samples were extracted with various QuEChERS versions and analyzed by LC/MS/MS. EN-QuEChERS without PSA gave a good recovery compared to others. Method performance parameters were satisfactory. Field incurred samples showed none of the tested analytes. Abstract: A single-run analytical method was developed to analyze the three herbicides azimsulfuron, bensulfuron-methyl, and mesotrione and its metabolite (4-methylsulfonyl-2-nitrobenzoic acid (MNBA)) in brown rice and rice straw using liquid chromatography-tandem mass spectrometry (LC/MS/MS). Samples extracted using various versions of Quick, Easy, Cheap, Effective, Rugged, and Safe "QuEChERS" (original unbuffered, acetate (AOAC), and citrate (EN) buffered) methods gave poor recoveries of all the tested analytes in both matrices. The extraction efficiency was improved when primary-secondary amine (PSA) sorbent was removed from the purification step, with the best recovery being achieved for EN-QuEChERS, which was subsequently used throughout the study. Overall, a determination coefficients ( R 2 ) ⩾ 0.995 was achieved at matrix-matched calibration curves at various concentration ranges. The recovery rates at three fortification levels (limit of quantification (LOQ), 1/2 maximum residue limit (1/2MRL), and MRL) ranged from 78 to 114.5, with relative standard deviations (RSDs) < 18% for all the tested analytes in both matrices. The LOQs for all herbicides were lower than the MRL set by the Ministry of Food and Drug Safety (MFDS), Republic of Korea. Field trials with the recommended, or double the recommended dose, revealed that the herbicides can safely be applied to rice, as no residues were detected in the harvested samples at 110 days.