2.5. Optimization of experimental parameters
2.5.1. Effect of sequential profile
The effect of sequential profiling of the solution zones (150 mL
of 0.5 mg L1 standard Al, 50 mL of 0.9 mmol L1 ECR reagent,
50 mL of 9 mmol L1 DTAB and 50 mL of 1 mol L1 acetate buffer
pH 6) on the homogenization of the monosegmented zone was
investigated by creating a monosegment of 300 mL total volume
using different sequence orders of solutions as listed in Table 3. The
flow rate of 30 mL s 1 was used to dispense the reaction zone to
MC. A sequence of off-line mixed (premixed) solutions was also
carried out for comparison. Once the sequence was created, the
stacked zones were moved to the mixing chamber, which caused
mixing of the stacked zone on the chamber.
2.5.2. Effects of sample and reagent volumes on sensitivity
Using the sequential profile of DTAB/ECR/Al/B (9 mmol L1
DTAB, 0.9 mmol L1 ECR reagent, 0.5 mg L1 standard Al and
1 mol L1 acetate buffer pH 6), the effects of acetate buffer, ECR