A Perkin Elmer Model 4100ZL electrothermal atomic absorption spectrophotometer (PerkinElmer Instruments, Shelton, CT, USA) with longitudinal Zeeman-effect background correction was used as detection system.
A Perkin Elmer Model 4100ZL electrothermal atomicabsorption spectrophotometer (PerkinElmer Instruments, Shelton,CT, USA) with longitudinal Zeeman-effect background correctionwas used as detection system.