Usefulness of the chaotropic effect in sample preparation for chromatographic analysis of acidic xenobiotics in human plasma

Abstract

In this study a new RP-HPLC with photo-diode array detection method for the determination of ibuprofen ((RS)-2-(4-isobutylphenyl)propionic acid) in human plasma samples was developed. Samples were prepared by SPE and analyzed by an isocratic elution mode over a C18 column using 80% methanol. A novel sample pretreatment method, based on the addition of ionic liquids possessing chaotropic ions to small human plasma sample (100 μL), was elaborated. 1-Butyl-3-methylimidazolium chloride and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM BF4 ) were tested from the point of view of extraction yield. Quantification was based on calibration curve applying diclofenac as the internal standard. Owing to dilution of plasma sample by 2 mM aqueous solution of BMIM BF4 before SPE, appropriate sample purification and extraction yields higher than 95% with precision lower than 2% can be achieved. Linear coefficients of correlation (r(2)) were >0.99 in the range of 0.3-5 μg/mL ibuprofen concentration in plasma. The limit of quantification was 65 ng/mL and the detection limit for ibuprofen was 19.5 ng/mL.

Plasma Sample Preparation for Solid Phase Extraction of Chosen Xenobiotics, Utilizing Salts Differing in Ion Chaotropicity

“…This idea has already been presented in our previous paper devoted to analysis of acidic drugs in plasma sample. [3] Satisfactory results obtained in this study led us to expand and explore in details the influence of other chaotropic additives on the recovery of various drugs differing in acid-base properties from plasma samples.…”

Comparison of mouse plasma and brain tissue homogenate sample pretreatment methods prior to high-performance liquid chromatography for a new 1,2,4-triazole derivative with anticonvulsant activity

“…An interesting alternative of sample preparation is the protein solubilization . In our earlier studies, we showed that the enrichment of plasma sample with only a few millimolar quantities of additives NaCl, NaPF 6 , or ionic liquid containing chaotropic ions 1‐ethyl‐3‐methylimidazolium tetrafluoroborate gave minimal matrix effect in further RP‐HPLC analysis .…”

Testing the capability of a polynomial‐modified gaussian model in the description and simulation of chromatographic peaks of amlodipine and its impurity in ion‐interaction chromatography

“…Chaotropic reagents or lipophilic ions proved to be advantageous over the classical ion‐pair reagents because they have a strong potential to provide the adequate peak shape and retention of the ionized analytes . In the literature several papers describing the applicability of the chaotropic reagents in the adjustment of the retention of basic pharmaceutical substances, as well as the improvement of peak symmetry and separation efficiency in reversed‐phase chromatographic systems are found .…”