A new flow injection single-standard calibration method for flame atomic absorption spectrometry based on dilution by microsample dispersion

A flow injection (FI) calibration method for flame atomic absorption spectrometry was developed which involved microsampling of a single standard using computer controlled stepper-motor driven peristaltic pumps. The theoretical basis for the method is given, demonstrating the feasibility of utilizing the linear relationship between the reciprocal of the dispersion coefficient (or analyte concentration) and sample volume in FI systems with dispersion coefficients higher than approximately 30. The errors introduced by loss of linearity at lower dispersions are discussed. Calibration curves constructed by metering microliter volumes of a single standard into a sample loop of approximately 100 μl were compared statistically to those obtained using a set of standard series within an 8 h working day. No significant differences between the two calibration procedures were observed.