Solution cathode glow discharge-atomic emission spectrometry using automated standard dilution analysis for the determination of Ca, Fe, and Zn in glucose oral solution

Abstract

Solution cathode glow discharge-atomic emission spectrometry (SCGD-AES) demonstrates significant potential as a metal element detection technique. However, its direct measurement of complex matrices still faces challenges in reliability due to matrix effects. To address this issue, standard dilution analysis (SDA) calibration emerges as an innovative strategy capable of effectively overcoming matrix interferences. This study investigated the feasibility of combining SDA with SCGD for practical complex sample analysis by employing automated SDA to collect calibration points over time and establish analytical curves. The results demonstrated that the proposed SCGD-SDA method performed effectively, showing that the relative deviations between the SCGD and inductively coupled plasma optical emission spectrometry (ICP-OES) methods were 5.2–9.4% for Ca, 3.1–7.3% for Fe, and 2.8–7.5% for Zn in five different oral glucose solutions. The detection limits of automated SDA reach ppb levels. SDA compensates for instrumental fluctuations and matrix effects, providing improved accuracy compared to external standard calibration (EC) while maintaining good agreement with ICP-OES reference values. The SCGD-SDA method establishes a simple and rapid analytical approach for trace element determination in glucose oral solutions.