Fluorometric determination of proline in honey by high-performance liquid chromatography after pre-column derivatization with 7-fluoro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-F)

Abstract

An optimization method of NBD-F derivatizationhas been developed for the determination of proline in honey using high performance liquid chromatography (HPLC) with fluorescence detection.To determine the free proline in different samples of honey, ultrasound extraction was performed using 0.1 M borate buffer solution as extraction solvent. The chromatographic separation was performed on a XDB C18 column (150 × 4.6 mm i.d.) using 0.1 M sodium acetate buffer solution (pH 7.2):methanol:tetrahydrofuran (900:95:5 respectively, v/v/v) as mobile phase A and methanol as mobile phase B at a flow rate of 1.0 mL/min with a run time of 10 min. The assay was linear over a range of 0.15 µg/mL to 100.00 µg/mL with a lower limit of detection of 3.00 mg/kg, and recoveries were greater than 90%. The intra-day and inter-day precision was less than 4%. This method was successful in determining free proline in honey, ranging from 80.5 mg/kg to 426.4 mg/kg indifferent honey samples.

Characterization of Chinese Unifloral Honeys Based on Proline and Phenolic Content as Markers of Botanical Origin, Using Multivariate Analysis

“…The extraction, derivatization and chromatographic separation method for proline in the honey samples were performed as described by Li et al [ 37 ]. Briefly, twenty milliliters of 0.1 M boric acid buffer was added to 1.0 g of honey and subject to ultrasound treatment for approximately 10 min.…”

Development and validation of a high‐performance liquid chromatography method for determination of lisinopril in human plasma by magnetic solid‐phase extraction and pre‐column derivatization

“…However, the method sensitivities were not adequate for pharmacokinetic applications owing to low reaction yield (El‐Enany, El‐Sherbiny, & Belal, ; Olojo, Xia, & Abramson, ; Saleh, El‐Henawee, Ragab, & El‐Hay, ; Song, Funatsu, & Tsunoda, ; Taha, Salama, & Fattah, ). NBD‐F is a more reactive fluorescent derivatization reagent which has attracted interest in the field of amino acid and peptide analysis (Higashi, Matsumura, & Fujii, ; Li et al, ; Song et al, ). To select the derivatization reagent, a comparative study between NBD‐Cl and NBD‐F for derivatization of lisinopril was carried out.…”

“…Based on the results, the developed MSPE method eliminated most of the interfering compounds and improved the method sensitivity. In addition, the high separation power of the novel HPLC columns and high selectivity of new fluorescent detectors make it possible to get rid of most of the remaining interferences (Li et al, ). Optimization of chromatographic condition was carried out by comparison of various analytical columns, including a Nova‐Pak® C 18 column, 60 Å, 4 μm, 3.9 × 150 mm (Waters, Milford, MA), a Eurospher® C 18 column, 100 Å, 3 μm, 4 × 100 mm (Knauer, Berlin, Germany) and a Kinetex® C 18 XB column 100 Å, 2.6 μm, 4.6 × 100 mm column (Phenomenex, Torrance, CA, USA).…”

DFT Analysis of Ions Conductivity of Proline in Certain Solvents: Calculation of Association Parameters

“…in honey by high-performance liquid chromatography after pre-column derivatization with 7-fluoro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-F), with a detection limit of 3.00 mg kg1 and recoveries of more than 90%. (Li et. al., 2015).…”