Table 1.
5 μm Carbon Fiber Microelectrode | 30 μm Carbon Fiber Microelectrode | |
---|---|---|
Detection Volume (pL) | 160 | 100 |
Peak Asymmetry (a) | 1.04 ± 0.00211 | 1.03 ± 0.00428 |
Peak Efficiency (N) | 38000 ± 300 | 38000 ± 300 |
Peak Area (pA*min) | 50 ± 8 | 130 ± 10 |
S/N Ratio | 400 ± 100 | 250 ± 50 |
Coulometric Efficiency | 43 ± 8 % | 78 ± 3 % |
Detection Limits (nM) | 230 ± 50 | 430 ± 80 |
Separations were performed in a 16 μm i.d. capillary with a 5-μm and a 30-μm diameter carbon fiber microelectrode. Detector volumes represent the total volume of the etched portion of the capillary less the volume displaced by the microelectrode. Peak asymmetries, obtained by measuring the front and back of the peak at 10 % of the peak height, are reported as the mean ± the standard error. Peak efficiencies are reported as the mean ± standard error from three separations, calculated using the peak widths at half-height. Peak areas and coulometric efficiencies are reported as the mean ± standard error from three separations. Concentration detection limits are reported as the mean ± standard error from three separations and were estimated using twice the signal-to-noise (S/N) ratio. Sample concentrations and buffer conditions as in Figure 2.