D -Limonene as a green bio-solvent for dispersive liquid–liquid microextraction of β-cyclodextrin followed by spectrophotometric determination

Abstract

Abstract In this paper d -limonene and β-carotene are introduced as two natural products in a dispersive liquid–liquid microextraction (DLLME) method for spectrophotometric determination of β-cyclodextrin (β-CD). Dissolved β-carotene in d -limonene exhibits strong absorption exhibits strong absorption intensity after performing. The absorption intensity of the extracted phase is increased in the presence of β-CD due to its interaction (complex formation) with β-carotene. This increase in the absorbance of the extracted phase is related to the β-CD concentration and was utilized as an analytical signal for determination of β-CD. The effect of chemical variables such as pH of the sample solution, nature and volume of dispersive solvent, volume of extraction solvent and extraction time on the DLLME method was studied and optimum conditions were established. The calibration curve was linear in the range of 1 × 10−4–6 × 10−3 mol L−1 (r = 0.9956) with a limit of detection 4 × 10−5 mol L−1. The relative standard deviation for eight replicate determinations of 1 × 10−3 mol L−1 and 5 × 10−3 mol L−1 of β-CD was 1.82% and 0.88% respectively. The proposed method was successfully applied to the determination of β-CD in spiked water and pharmaceutical samples and good recoveries in the range of 94.2–108.0% were obtained.