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3. Glyphosate, Environmental Chemistry Method.
https://www.epa.gov/ sites/production/files/2014-12/ documents/408816-01-w.pdf (accessed October 7, 2016).
4. Ehling, S.; Reddy, T.M. Total Residue Analysis of Glyphosate and Three Metabolites in Soy and Milk-based Nutritional Ingredients by Derivatization with Fluorenylmethyloxycarbonyl Chloride and Liquid Chromatography/ Mass Spectrometry. Poster in Proceedings of ASMS 2016, San Antonio, TX.
Figure 4. Glyphosate in Instant Oatmeal. Two MRM transitions are shown: 168/83 in blue and 168/79 in red. Conclusions
The proposed method developed for glyphosate and related compounds uses LC-MS/MS detection and an ion-exchange polymer-based apHera NH2 column that is stable under higher pH conditions. Mobile phase contained 20 mM carbonate buffer with 5% methanol, was fully compatible with mass spectrometry and allowed efficient ionisation of analytes. Sample preparation methodology included cleanup using polymeric SPE, which was successfully applied to samples of cereals including oatmeal and infant cereal products. Cleanup that included ultrafiltration was developed for wheat- containing products and was successfully applied to wheat flour samples. Use of isotopically labelled standards resulted in good accuracy for glyphosate
determination and allowed the use of solvent-based calibration curves. The method was applied to multiple grain products; significant levels of glyphosate higher than 0.8 ppm were found in oatmeal and wheat flour products.
References
1. What Do We Really Know About Roundup Weed Killer? http://
news.nationalgeographic. com/2015/04/150422-glyphosate- roundup-herbicide-weeds/ (accessed October 10, 2016).
2. Glyphosate; tolerances for residues.
https://www.gpo.gov/fdsys/pkg/CFR- 2014-title40-vol24/xml/CFR-2014-title40- vol24-part180.xml#seqnum180.364 (accessed October 7, 2016).
Microplate Products for LC/MS and GC/MS Sample Preparation
Porvair Sciences offer an extensive range of sample preparation products for mass spectrometry techniques including LC/MS and GC/MS.
Together with sister company JG Finneran Associates, Porvair Sciences is able to offer an unmatched selection of innovative glass vials, seals, closures, and microplates to enhance chromatography and mass spectrometry workflows. In addition, mass spectrometry-certified kits for sample preparation and use in autosamplers are available to simplify and save time.
Proven in leading labs worldwide, the highly acclaimed P3 (Protein Precipitation Plate) sets the standard for cost effectively and efficiently removing proteins from biological samples that can interfere with downstream LC/MS and GC/MS applications.
For over twenty years, Porvair Sciences’ Microlute™ 96-well SPE plates have been helping scientists increase the throughput of their mass spectroscopic analyses by speeding up sample preparation. With a range of quality polymeric sorbent materials available, Microlute™ sets the industry benchmark for 96-well plate-based solid phase extraction. The complete Microlute™ system provides a matched filter plate, vacuum manifold and choice of collection plates with the option of a dedicated sample concentrator, if needed.
Deep well polypropylene microplates are routinely used for sample storage in many laboratories. An essential aspect of their manufacture is the selection of clean raw materials for injection moulding. Polypropylene is an inert and heat-resistant material, ideal for sample storage. However, all grades of polypropylene are not the same. In independent comparative testing, Porvair Sciences’ deep well plates have been repeatedly shown to contain near zero contaminants that may leach out and interfere with your LC/MS or GC/MS analyses.
Finneran Porvair Sciences will be exhibiting its complete range of products for sample preparation to storage that provide effective solutions for MS challenges at booth 310 at the forthcoming 67th ASMS Conference on Mass Spectrometry in Atlanta, Georgia, USA (2-6 June).
More information online:
ilmt.co/PL/M1Da
5. Quick Polar Pesticides Method.
http://www.eurl-pesticides. eu/docs/public/tmplt_article. asp?CntID=887&LabID=200&Lang=EN (accessed January 29, 2019).
6. Chamkasem,. N.; Harmon, T. Direct determination of glyphosate, glufosinate, and AMPA in soybean and corn by liquid chromatography/tandem mass spectrometry. Anal. Bioanal. Chem. 2016, 408(18), 4995-5004.
Trademarks
aPhera, Supel-Select, PESTANAL are trademarks of Merck KGaA, Darmstadt, Germany. Roundup is a trademark of Monsanto Technology LLC.
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