3.2.1. Effect of sequential profile
The effect of sequential profiling of the solution zones using
different sequential orders of solutions as listed in Table 3 was
investigated. It was found that the signals obtained from the
sequence number 9 (DTAB/Al/ECR/B) and 10 (DTAB/ECR/Al/B)
were comparable to those obtained from off-line mixed. The
reproducibility of the sequence number 9 and 10 were 1.32 and
0.82%RSD, respectively. Therefore, the sequence number 10 was
chosen from its better reproducibility.