Standard dilution analysis (SDA) using high-resolution continuum source flame atomic absorption spectroscopy for the determination of Li, Cr, and Ni in complex matrices

• Published in: Microchemical journal Vol. 212; p. 113470
• Main Authors: Bustos, Daniel E., Rivas, Ricardo E.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2025
• Subjects: Complex matrices; Gradient dilution; HR-CS FAAS; Matrix effects; Standard dilution analysis (SDA); Matrix effects; Gradient dilution; Standard dilution analysis (SDA); HR-CS FAAS; Complex matrices
• ISSN: 0026-265X
• DOI: 10.1016/j.microc.2025.113470

[Display omitted] •Automatic method, simpler and faster than conventional addition standard.•Use of SDA approach for the determination of Li, Cr, and Ni in the presence of complex matrices without sample treatment.•The method requires only two solutions for carrying out the entire analysis.•The analyte and IS respective signals could be recorded simultaneously (sim-SDA) or sequentially (seq-SDA).•Smaller volumes than those typically used in atomic flame and plasma techniques. Standard dilution analysis (SDA) is a non-conventional calibration method that combines standard addition (SA) and internal standard (IS) calibrations. Only two solutions are required: the first corresponds to a sample fortified with the element of interest and an internal standard, and the second is a mixture of the same sample and the corresponding blank. Both solutions were gradually mixed (and diluted), emulating an automatic standard addition procedure. Adding an internal standard allowed the method to correct the sensitivity variations produced by possible physical interferences generated during the nebulization. The mixing process of both solutions was carried out automatically by a simple experimental setup using a syringe pump to ensure repeatability in the measurements. Taking advantage of the single or multi-elemental (subject to feasibility) approach of the high-resolution continuum source flame atomic absorption spectroscopy technique (HR-CS FAAS), the analyte and IS respective signals could be recorded in two different ways, simultaneously in a single experiment (sim-SDA) or sequentially (seq-SDA) in two separate experiments. This work focused on using the appropriate SDA approach for determining Li, Cr, and Ni in blood serum, cough syrup, and a protein supplement without laborious sample treatment, evaluating the HR-CS-FAAS technique as the detection system. The results were very similar to those obtained with the traditional standard addition method, demonstrating the feasibility of the SDA method in determining elements of significant interest in complex matrices. The developed method introduced some improvements, such as the automation of the process and the substantial reduction of the usual volume used in the atomic flame technique.