Optimization of Adsorbent Layer Type and Developing Solvent in Coccidiostats Sample Preparation with Procedure of Solvent Front Position Extraction

Abstract

Coccidiostats are drugs used against coccidiosis, a common disease among breeding animals. Their widespread application leads to the appearance of their residues in food, which is potentially harmful for human health and life. The European Union has established limits of concentrations of these drugs in premixtures and food. Nowadays, there are many methods for monitoring coccidiostats’ presence in market products, but their frequent weakness is sample preparation. Solvent Front Position Extraction is a planar chromatography-based sample preparation method that allows for effective assay of samples with coccidiostats when coupled with LC-MS/MS. The purpose of this research was to find common conditions for the effective isolation of eight coccidiostats from biological sample components with both lower and higher retention than the substances of interest. The acquired results were used for effective isolation of monensin and salinomycin from the premixture samples and allowed for their quantitative determination. The application of a semi-automatic device for the development of chromatograms positively impacted the results, confirming the effectiveness of the method for determining coccidiostats in biological samples.

Solvent Front Position Extraction and some conventional sample preparation techniques for the determination of coccidiostats in poultry feed by LC–MS/MS

“…It was intended to be a cheap, simple and precise method for simultaneous preparation of many samples. Recently, SFPE was presented as very effective with separation of tryptophan from human plasma 27 and with monensin and salinomycin from samples of feed premixes 19 . What is important, effectiveness of separation of substances of interest from matrix elements could be easily observed on chromatograms (MRM chromatograms are available as Supplementary Fig.…”

“…1 A) 26 . Then, after evaporation of solvent, the chromatograms of the samples were developed with a mixture of toluene and methanol in a volume ratio of 1:1 (v/v) 19 to a distance of 30 mm (Fig. 1 B).…”

“…1 B). Based on the last research 19 , listed coccidiostats were expected to reach a distance of about 24 mm and were observed under illumination of 254 nm light and white light using the CAMAG TLC Visualizer (Fig. 1 C).…”

“…It allowed to effectively separate 5 coccidiostats from matrix elements and determine them quantitatively. In the latest work from 2020 19 , SFPE was optimized for the development of chromatograms of pure coccidiostats with a prototype of a semiautomatic device with a moving pipette for delivering the eluent to the chromatography plate for the first time and it allowed quantification of coccidiostats in samples of two commercially available premixes, whose coccidiostats content was in the range 12–19.4%. In this work the main goal was a quantification of 7 (maduramycin, narasin, salinomycin, monensin, lasalocid, robenidine, nicarbazin and nigericin as an internal standard) coccidiostats simultaneously in feed samples at a ML concentrations, which values are much lower than before (μg/kg) due to optimization of method for practical use.…”

Sample preparation for planar chromatography

“…Solvent front position extraction is a variation of pSPE in which the target compounds and an internal standard for quantification are in a single zone at the solvent front position of the final development [114][115][116][117][118]. This has the advantage that the target compounds are concentrated in a narrow zone with an easily defined location for subsequent solvent extraction.…”