Quantifying indium with ion chromatography in hydro- and biohydrometallurgical leaching solutions

A Fast and Efficient Procedure of Iron Species Determination Based on HPLC with a Short Column and Detection in High Resolution ICP OES

The optimization and application of a new hyphenated procedure for iron ionic speciation, i.e., high performance liquid chromatography (HPLC) with short cation-exchange column (50 mm × 4 mm) coupled to high resolution inductively coupled plasma optical emission spectrometry (ICP hrOES), is presented in this paper. Fe(III) and Fe(II) species were separated on the column with the mobile phase containing pyridine-2,6-dicarboxylic acid (PDCA). The total time of the analysis was approx. 5 min, with a significantly low eluent flow rate (0.5 mL min^-1) compared to the literature. Additionally, a long cation-exchange column (250 mm × 4.0 mm) was used as reference. Depending on the total iron content in the sample, two plasma views were chosen, e.g., an attenuated axial (<2 g kg^-1) and an attenuated radial. The standard addition method was performed for the method's accuracy studies, and the applicability was presented on three types of samples: sediments, soils, and archaeological pottery. This study introduces a fast, efficient, and green method for leachable iron speciation in both geological and pottery samples.

Iron species determination by high performance liquid chromatography with plasma based optical emission detectors: HPLC-MIP OES and HPLC-ICP OES

The paper presents an independent application of two hyphenated techniques, wherein an identical chromatographic system i.e. high performance liquid chromatography (HPLC) was coupled to microwave induced plasma optical emission spectrometry (MIP OES) or inductively coupled plasma optical emission spectrometry (ICP OES). A cation-exchange column and a mobile phase based on pyridine-2,6-dicarboxylic acid (PDCA) were employed to separate Fe(II) and Fe(III) within 300 s. Additionally, two methods of sample preparation were employed. Optimization and validation of both methods were conducted parallel. The applicability was presented with different sample matrix types: post-glacial sediments, archaeological pottery, soils located in the proximity of industry wastes disposal site, river sediments and yerba mate (Ilex paraguariensis). Obtained results were compared in terms of the excitation source (microwave induced or inductively coupled) and supplied gas (nitrogen or argon). The research introduces HPLC-MIP OES for iron speciation analysis and its applicability were critically evaluated with HPLC-ICP OES.