PTV In Situ Derivatization of Several Acidic Herbicides Using a Newly Developed GC-MS/MS Method

Diana Puiu,Roxana Scutariu,Toma Galaon,Alina Tatarus,Liliana Cruceru

doi:10.37358/rc.20.1.7814

Abstract

The uses of herbicides increased during the last decades. Because acid herbicides can be identified in environmental samples, specific analytical methods are required. In this work a new GC-MS/MS method was developed in order to detect some pyridinecarboxylic acids (clopyralid, triclopyr and fluroxypyr) and a methoxybenzoic acid (dicamba) from environmental water samples. Because these polar analytes involve a derivatization step, a Programmed Temperature Vaporizing injector (PTV) was used to shape the derivatization conditions and to minimize the working time. This process is called in port derivatization (IPD), a relative new technique which encourages greener practices in analytical laboratory. MtBSTFA was chosen to be the most suitable silylation agent due to generation of specific derivatized analyte structures, which can be further fragmented in the EI ionization source to produce specific ions for the targeted analytes, easily detectable with high sensitivity.Few studies analyzed the derivatization of above-mentioned herbicides with MtBSTFA, while no other paper work was identified in studying the in port derivatization of these compounds. The results revealed that the developed method is sensitive and robust to obtain quantitation limits below 10 ng/L.

Highlights

The uses of herbicides increased during the last decades
In the present study it was developed a new Programmed Temperature Vaporizing injector (PTV)-GC-MS/MS method preceded by a SPE extraction and concentration step to detect several pyridine herbicides from environmental samples with high sensitivity and reduced sample preparation time
The MtBSTFA classical silylation process of pyridine carboxylic herbicides which was realized at 80°C for 60 min was shortened by direct reaction in the GC PTV inlet

Summary

Introduction

The uses of herbicides increased during the last decades. Because acid herbicides can be identified in environmental samples, specific analytical methods are required. Derivatization in PTV inlet does not require high sample volumes, instead it necessitates optimization of specific operational parameters which can lead to a complete reaction of the analytes in a shorter time period and with much less sample preparation steps, reducing significantly the error sources and improving method reproducibility. In the present study it was developed a new PTV-GC-MS/MS method preceded by a SPE extraction and concentration step to detect several pyridine herbicides from environmental samples with high sensitivity and reduced sample preparation time.

Results

Conclusion