Abstract
Tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy) 3 post staggered 2+) electrogenerated chemiluminescence (ECL) is investigated for the detection of glyphosate (HO 2CCH 2NHCH 2PO 3H 2, N-(phosphonomethyl)glycine) and several structurally related compounds separated by ion exchange chromatography. These related compounds are iminodiacetic acid (IDA, HO 2CCH 2NHCH 2CO 2H), diethanol amine (DEA, HOCH 2CH 2NHCH 2CH 2OH), hydroxyethyl glycine (HEG, HO 2CCH 2NHCH 2CH 2OH), and glycine (NH 2CH 2CO 2H). Resulting ECL intensities increase in the order: glycine < DEA < HEG < IDA < glyphosate. The study of the effect of pH on chemiluminescence (CL) emission intensity for the compounds investigated showed that this detection method is most sensitive in the alkaline pH range. The detection limit for glyphosate is 0.01 μM with a linear working range that extends five orders of magnitude. The separation is done using both cation exchange and anion exchange chromatography. For the cation exchange separation, both post-column addition of Ru(bpy) 3 post staggered 2+ and adjustment of pH is required. Incorporating Ru(bpy) 3 post staggered 2+ in the mobile phase has no benefit since post-column adjustment of pH is still necessary. For the anion exchange separation, studies are done with both post-column addition of Ru(bpy) 3 post staggered 2+ and with Ru(bpy) 3 post staggered 2+ incorporated in the mobile phase. Including Ru(bpy) 3 post staggered 2+ in the mobile phase eliminates the need for any post-column reagent addition, decreasing band broadening and simplifying instrumental set-up. Including Ru(bpy) 3 post staggered 2+ in the mobile phase also modifies the stationary phase, which causes retention times of the analytes to decrease. With anion exchange chromatography, separation of the analytes is accomplished using both isocratic and step-gradient elution. Although step-gradient elution gives the best separation of the analytes examined, the method of including Ru(bpy) 3 post staggered 2+ in the mobile phase works best when the compounds of interest can be separated isocratically.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
