Precision and linearity of inorganic analyses by ion chromatography

• Published in: Journal of Chromatography A Vol. 706; no. 1; pp. 21 - 29
• Main Authors: Tartari, Gabriele A., Marchetto, Aldo, Mosello, Rosario
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 07.07.1995
• ISSN: 0021-9673
• DOI: 10.1016/0021-9673(94)01222-Z

The repeatability of the measurements of peak areas for calibration solutions and the precision of anion and cation determinations (3–600 μM) in freshwater are discussed on the basis of 2 years of measurements on calibration solutions and stabilized internal standards. Anion measurements show higher repeatability of the measurements of peak areas for calibration solutions (R.S.D. 2–5%) and precision (R.S.D. 2–8%) than those of cations (R.S.D. 2–10% and 2–15%, respectively). Results for the calibration technique show that multi-point (6–8 concentrations), quadratic or cubic regressions permit a correct quantification over a wide range (1.5–2 orders of magnitude) of concentrations. Thanks to the repeatability of the measurements of peak areas for calibration solutions, only two calibrations, at the beginning and end of a batch of 20–30 samples, are adequate. These conditions give better results than calibrations performed with 2–3 points and repeated every 8–10 samples.