Molecularly imprinted nano particles combined with miniaturized homogenous liquid–liquid extraction for the selective extraction of loratadine in plasma and urine samples followed by high performance liquid chromatography-photo diode array detection

Abstract

In this work a molecularly imprinted polymer was developed as a selective sorbent for extraction of loratadine (as a model) in complex matrices followed by miniaturized homogeneous liquid–liquid extraction (MHLLE) for the first time. The molecularly imprinted polymer (MIP) which is based on loratadine as the template was synthesized successfully by precipitation polymerization and was used as a selective sorbent. This technique was applied for preconcentration, sample preparation, and determination of loratadine using high performance liquid chromatography-photo diode array detection (HPLC-PDA). Optimization of various parameters affecting molecular imprinted solid phase extraction (MISPE), such as pH of adsorption, composition and volume of eluent, adsorption and desorption times were investigated. Besides, in the subsequent stage (MHLLE) the type and volume of extraction solvent, sodium hydroxide amount, surfactant concentration, and extraction time were investigated and optimized. Under the optimal condition, maximum enrichment capacity and Langmuir constant were 91mgg−1 and 0.014Lmg−1, respectively. Furthermore, enrichment factor and extraction recovery of MIP-MHLLE method were 30 and 90%, respectively. The LOD of the proposed method was 0.2μgL−1 and a linear dynamic range of 1–1000μgL−1 was obtained with correlation coefficient of greater than 0.998. The present method was applied for extraction and determination of loratadine in plasma and urine samples in μgL−1 levels and satisfactory results were achieved (RSD <8% based on three replicate measurements).