Development of an LC-MS/MS Method for Simultaneous Determination of the Quaternary Ammonium Herbicides Paraquat, Diquat,
- PDF / 637,145 Bytes
- 7 Pages / 595.276 x 790.866 pts Page_size
- 37 Downloads / 209 Views
Development of an LC-MS/MS Method for Simultaneous Determination of the Quaternary Ammonium Herbicides Paraquat, Diquat, Chlormequat, and Mepiquat in Plant-Derived Commodities Anna Bauer 1 & Jens Luetjohann 1
&
Sascha Rohn 2 & Jürgen Kuballa 1 & Eckard Jantzen 1
Received: 30 August 2017 / Accepted: 13 February 2018 # Springer Science+Business Media, LLC, part of Springer Nature 2018
Abstract An optimized method for the determination of residues of the plant growth regulators chlormequat, mepiquat, paraquat, and diquat in plant-derived commodities using LC-MS/MS was developed. As an exemplary, but very challenging commodity, the focus was set on the oil seed chia and the coverage of incurred residues of these quaternary ammonium compounds. The study describes the evaluation of optimum extraction conditions, particularly of the extraction solvent and a potential thermal treatment. The final procedure was accomplished by the extraction solvent methanol/hydrochloric acid at room temperature without the application of an extra heating step. The LC-MS/MS measurement was performed on an Obelisc R column (SIELC) within 16 min of separation time. For compensating matrix effects and differences in recovery rates, the isotopically labeled internal standards (ILIS) diquat d4, paraquat d6, mepiquat d3, and chlormequat d4 were added to the samples prior to the extraction. The validation of the method for the matrices tomato, lemon, sultana, wheat, and chia seed was carried out according to the actual guidance document SANTE/11945/2015 by the European Commission. The precision and accuracy were determined in five replicates at residual levels of 0.010 and 0.100 mg/kg obtaining recovery rates between 77 and 120% and RSDs between 1 and 13%. By means of the analytical method developed, it is possible to meet the strict requirements for the analysis of organic and baby food. Keywords Diquat . Paraquat . Chlormequat . Mepiquat . Chia seed . LC-MS/MS
Introduction Chlormequat (2-chloroethyltrimethylammonium ion, CQ), mepiquat (1,1-Dimethylpiperidinium ion, MQ), paraquat (1,10dimethyl-4,40-bipyridinium ion, PQ), and diquat (1,10-ethylene2,20-bipyridinium ion, DQ) belong to the group of quaternary ammonium salts (Bquats^) (Aramendía et al. 2006). Their structural formulas are depicted in Fig. 1. Paraquat and diquat are bipyridylium herbicides, widely used all over the world. Diquat is a non-selective herbicide, contact desiccant, and frequently
* Jens Luetjohann [email protected] 1
Research and Development Department, GALAB Laboratories GmbH, Am Schleusengraben 7, 21029 Hamburg, Germany
2
Institute of Food Chemistry, Hamburg School of Food Science, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany
used for weed control (Pizzutti et al. 2016). Paraquat is used as active agent for controlling weed, but has been banned in the EU since 2007 (Pizzutti et al. 2016; Commission of the European Communities 2007). Chlormequat and mepiquat are quaternary ammonium salts used as plant growth regulators for reducing unwan
Data Loading...
