Determination of selected herbicides employed in sugarcane crops by disposable pipette tip (DPX) extraction followed by LC-MS/MS and GC-MS/MS

Abstract

A disposable pipette tip extraction (DPX) method followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was developed and validated to determine eleven herbicides employed in sugarcane crops. After improving conditions, the DPX method consists of conditioning a C18 tip with 0.3 mL of methanol, followed by the same volume of water and 0.15 mL of the sample. After completing the sorption interaction, the sample was dispensed, and elution was made with 0.15 mL of methanol before collecting the extract for injection. The total extraction time was 4 min, and recoveries ranged from 59.1 to 76.5%. DPX method was compared to cartridge solid-phase extraction, which presented recoveries between 30.4 and 108.6%. SPE consumed four times more solvent, total extraction time is five times longer than DPX, and cartridges are more expensive than the DPX tips. DPX performance was also evaluated by gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). The recoveries were similar to LC-MS/MS. Furthermore, the DPX-C18-LC-MS/MS method was applied to analyze sugarcane-derived juice samples. Results indicate that the method can determine the herbicides in actual samples and other sugarcane matrices.

Graphical Abstract

Keywords:

• Disposable pipette tip extraction
• DPX
• herbicides determination
• LC-MS/MS
• sugarcane

Acknowledgments

The authors are grateful for the financial support from i) the Coordination for the Improvement of Higher Education Personnel (CAPES – Brazil, Finance Code 001), ii) the São Paulo Research Foundation (FAPESP – Brazil, Grants 2019/22724-7, 2017/02147-0, 2015/15462-5, and 2014/07347-9), iii) the National Council for Scientific and Technological Development (CNPq – Brazil, 307293/2014-9; 308843/2019-3).

Disclosure statement

The authors report that there are no competing interests to declare.