Extending the dynamic range of flame atomic absorption spectrometry: a comparison of procedures for the determination of several elements in milk and mineral waters using on-line dilution.

Three approaches based on continuous flow methodology are assessed for the purpose of extending the dynamic range of flame atomic absorption spectrometry. The determination of several elements in infant liquid and powdered milk and water samples is used to check the performances of the manifolds. Two of the systems are fully computer-controlled and permit a calibration graph to be obtained by using a single standard solution. The results confirm that continuous flow methodology is a reliable alternative to the time-consuming common dilution procedures based on glassware. Since the systems are versatile and permit a wide range of degrees of dilution to be obtained, they can be easily adapted for the automated or semi-automated analysis of other liquid samples which are too concentrated to be aspirated directly into the atomic absorption spectrometer.