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Rapid resolution liquid chromatography method for determination of malathion in pesticide formulation

Velkoska-Markovska L., Petanovska-Ilievska B.

Acta Chromatographica

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2020

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Vol. 32, no. 4

256--259

EN

This paper presents a new, simple, precise, and accurate rapid resolution liquid chromatography (RRLC) method for determination of an active ingredient malathion in the pesticide formulation. The analysis was performed on a Poroshell EC 120-C18 (50 mm × 3 mm, 2.7 μm) analytical column using isocratic elution with a mobile phase consisted of acetonitrile–water (50:50, v/v), a flow rate of 1 mL/min, a constant column temperature at 25 °C, and ultraviolet-diode array detection (UV-DAD) at 220 nm. The specificity, selectivity, linearity, precision, and accuracy were tested for the method validation according to the Collaborative International Pesticides Analytical Council (CIPAC) and Directorate General Health and Consumer Protection (SANCO) guidelines and all tested parameters were found within acceptance criteria. The obtained results indicated that the proposed method can be used for routine analysis of the active ingredient malathion in the pesticide formulation “Etiol tecni” following the CIPAC and SANCO rules. The run time of analysis under the stipulated chromatographic conditions was about 2.5 min, meaning that the proposed method requires a small volume (< 1.5 mL) of the organic solvent (acetonitrile) making it cost-effective.

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Development and validation of high-performance liquid chromatography method for determination of some pesticide residues in table grape

Velkoska-Markovska L., Petanovska-Ilievska B., Jankulovska M. S., Ilievski U.

Acta Chromatographica

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2018

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Vol. 30, no. 4

250--254

EN

This study presents the development and validation of a new reversed-phase high-performance liquid chromatography (RP-HPLC) method for simultaneous determination of captan, folpet, and metalaxyl residues in table grape samples with ultraviolet–diode array detection (UV–DAD). Successful separation and quantitative determination of analytes was carried out on LiChrospher 60 RP-select B (250 × 4 mm, 5 μm) analytical column. Mixture of acetonitrile–0.1% formic acid in water (65:35, v/v) was used as a mobile phase, with flow rate of 1 mL/min, constant column temperature at 25 °C, and UV detection at 220 nm. The target residues were extracted with acetone by ultrasonication, followed by a cleanup using liquid–liquid extraction (LLE) and solid-phase extraction (SPE). The obtained values for multiple correlation coefficients (R2 > 0.90), relative standard deviation (RSD) of retention times, peak areas and heights (RSD ≤ 2.25%), and recoveries ranging from 90.55% to 105.40%, with RSD of 0.02% to 5.37%, revealed that the developed method has a good linearity, precision, and accuracy for all analytes. Hence, it is suitable for routine determination of investigated fungicides in table grape samples.

3

Development of reverse-phase high-performance liquid chromatography method for simultaneous determination of sodium benzoate and potassium sorbate in beverages

Petanovska-Ilievska B., Velkoska-Markovska L., Jankulovska M.

Acta Chromatographica

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2017

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Vol. 29, no. 3

345--358

EN

Reverse-phase high-performance liquid chromatography (RP-HPLC) method for simultaneous determination of sodium benzoate and potassium sorbate in beverages was developed using high speed column. The simple and rapid reverse-phase method for quantitative determination of both preservatives was established on LiChroCART® Purospher STAR RP-18e (30 mm × 4 mm; 3 μm) column, mobile phase consisted of acetonitrile-phosphate buffer (pH = 3.5) in volume ratio of 8:92 (v/v), flow rate of 1 mL min−1, ultraviolet (UV) detection at 195 nm for sodium benzoate and 260 nm for potassium sorbate, and constant column temperature at 25 °C. Linearity, precision, accuracy, limit of quantification (LOQ), and limit of detection (LOD) were tested for method validation. Linearity range for sodium benzoate was 6.04–200.27 mg L−1 (R2 = 0.999) while, for potassium benzoate (R2 = 0.999), 12.19–406.36 mg L−1. The RSD values ≤1.03% demonstrate excellent intra-day precision. LOD for sodium benzoate and potassium sorbate was 0.004 and 0.003 mg L−1, while LOQ was 0.012 and 0.009 mg L−1, respectively. This method was applied for quantitative determination of investigated preservatives in beverages which were taken from Macedonian markets.

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Simultaneous determination of phenmedipham, desmedipham, and ethofumesate in a pesticide formulation by normal-phase high-performance liquid chromatography

Velkoska-Markovska L., Petanovska-Ilievska B., Vodeb L.

Acta Chromatographica

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2008

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Vol. 20, no. 1

109-118

EN

A normal-phase high-performance liquid-chromatographic method has been developed for simultaneous quantitative analysis of phenmedipham, desmedipham, and ethofumesate in a pesticide formulation. Analysis was performed on a 25 cm × 0.4 cm, 5- µm particle, CN column with n-hexane-dichloromethane 40:60 (v/v) as mobile phase at a flow rate of 1 mL min-1. UV detection was performed at 270 nm; the constant column temperature was 25°C. The run time under these chromatographic conditions was less than 8 min. Calibration plots were linear in the concentration range 76-380 µg mL-1 for phenmedipham, 72-360 µg mL-1 for desmedipham, and 52-260 µg mL-1 for ethofumesate. Statistical evaluation by analysis of variance showed the intra-day repeatability (n = 8) and inter-day precision (n = 3) of the assay were satisfactory. The sensitivity of the method, as the limits of detection (LOD) and quantification (LOQ) for each active ingredient, was also determined.