Sequential injection system with in-line solid phase extraction and soil mini-column for determination of zinc and copper in soil leachates

• Published in: Talanta (Oxford) Vol. 185; pp. 316 - 323
• Main Authors: Paluch, Justyna, Mesquita, Raquel B.R., Cerdà, Víctor, Kozak, Joanna, Wieczorek, Marcin, Rangel, António O.S.S.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.08.2018
• Subjects: Copper; Mini soil column; Sequential injection analysis; Soil leachates; Zinc; Sequential injection analysis; Soil leachates; Copper; Mini soil column; Zinc
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2018.03.091

A sequential injection (SI) system equipped with in-line solid phase extraction column and in-line soil mini-column is proposed for determination of zinc and copper in soil leachates. The spectrophotometric determination (560 nm) is based on the reaction of both analytes with 1-(2-Pyridylazo)-2-naphthol (PAN). Zinc is determined after retaining copper on a cationic resin (Chelex100) whereas copper is determined from the difference of the absorbance measured for both analytes, introduced into the system with the use of a different channel, and zinc absorbance. The influence of several potential interferences was studied. Using the developed method, zinc and copper were determined within the concentration ranges of 0.005–0.300 and 0.011–0.200 mg L−1, and with a relative standard deviation lower than 6.0% and 5.1%, respectively. The detection limits are 1.4 and 3.0 µg/L for determination of zinc and copper, respectively. The developed SI method was verified by the determination of both analytes in synthetic and certified reference materials of water samples, and applied to the determination of the analytes in rain water and soil leachates from laboratory scale soil core column and in-line soil mini-column. [Display omitted] •Development of a sequential injection method for bi-parametric determination of zinc and copper with the same operation cycle.•Combining in the same manifold the bi-parametric determination with in-line soil leachate simulation.•Effective application of the specially designed in-line soil mini column (ILSM) for leachate studies.•Application of the developed SI-SPE method to natural waters, off-line and in-line produced leachates.