Development of an ionic liquid-based microextraction system (ILBME) for sensitive spectrophotometric analysis of neodymium(III) ions in environmental samples

Abstract

ABSTRACT Introducing a precise, sensitive and simple system for determining neodymium(III) ions in aquatic samples could enhance the capabilities of routine instruments, particularly in terms of detection limits. Coupling a powerful preconcentration system, such as ionic liquid-based microextraction (ILBME), with a spectrophotometer can successfully achieve this goal. A sensitive and simple microextraction method based on a task-specific ionic liquid, designated [PDmim][Cl2], is described, in which the imidazolium-based ionic liquid served dual roles as both the chelating agent and the extraction phase. The ionic liquid was synthesized and characterized before being applied in microextraction procedure. The optimized microextraction results indicate that neodymium concentrations up to 5.10 µg L−1 can be successfully determined. The method characteristics, including the limit of detection (LOD), limit of quantification (LOQ), intra-day and inter-day relative standard deviations (RSDs), preconcentration factor (PF), enrichment factor (EF) and linear dynamic range (LDR), were found to be 1.53 µg L−1, 5.10 µg L−1, 3.83%, 4.44%, 123, 111.1 and 5.0–125.0 µg L−1, respectively. For method validation, the standard addition method using standard reference material (SRM) was employed, and the recovery range from real samples analyses was between 99.3% and 101.0%.