Solid‐phase extraction and residue determination of glyphosate in apple by ion‐pairing reverse‐phase liquid chromatography with pre‐column derivatization

Abstract

A new method for glyphosate residue determination in apple has been developed. A SPE cartridge was used to clean up the samples before derivatization. Glyphosate was derivatized with 4-chloro-3,5-dinitrobenzotrifluoride (CNBF) and quantified by reverse ion-pair liquid chromatography using cetyltrimethylammonium bromide (CTAB) as ion-pair reagent. In pH 9.5 H(3)BO(3)-Na(2)B(4)O(7) medium, the reaction of glyphosate with CNBF was complete after 30 min at 60 degrees C. The stability of the derivative on exposure to light at room temperature in methanol-water was demonstrated. The labeled glyphosate was separated on a Kromasil C(18) column (250 x 4.6 mm, 5 microm) at room temperature and UV detection was applied at 360 nm. Separation was achieved within 15 min in gradient elution mode. The correlation coefficient for the method was 0.9998 at concentrations ranging from 0.1 to 50 microg/g. The calculated recoveries for glyphosate in apple were from 86.00 to 99.55%, and the relative standard deviations (n = 6) were from 1.43 to 6.32. The limit of detection was 0.01 microg/g for glyphosate in apple.

High-performance liquid chromatographic method for determination of amino acids by precolumn derivatization with 4-chloro-3,5-dinitrobenzotrifluoride

“…The CNBF derivatization was rapid at moderate temperature, along with the resultant derivatives being very stable and of high ultraviolet and fluorescent absorption [41][42][43][44][45][46][47]. There were not any multiple derivatives and by-products except CNBF hydrolysis compound in the reaction, while excess reagent and its hydrolysis compound could not disturb the separation.…”

Enrichment and low‐level determination of glyphosate, aminomethylphosphonic acid and glufosinate in drinking water after cleanup by cation exchange resin

“…Adequate cleaning combined with the assigned chromatography showed a very good signal‐to‐noise ratio. This validated procedure with the achieved LODs of <25 ng/L represents an extremely sensitive and efficient method for the regulation of phosphonic acid herbicides in comparison with data in the literature 9, 24.…”

“…The procedure prevents the interactions by metal ions such as Ca, which lead to losses in analytes during derivatization and enrichment 2, 3. Compared with other derivatization reagents, FMOC showed a fast and precise reaction with a very sensitive detection of the derivatives 9, 24. This enables the determination of the phosphonic acid herbicides within the nanogram range.…”

Determination of tobramycin in soil by HPLC with ultrasonic-assisted extraction and solid-phase extraction

“…4-Chloro-3,5-dinitrobenzotrifluoride (CNBF) is a novel derivatization reagent, which has been known to react with primary or secondary amines in the presence of base to produce stable N-substituted-2,6-dinitro-4-(trifluoromethyl) benzamine derivatives which display satisfactory ultraviolet absorption. There were no any other multiple derivatives and by-products except CNBF hydrolysis compound in the reaction, while excess reagent and its hydrolysis compound could not disturb the separation [25][26][27][28][29].…”