Table 1

Quantitative parameters for methods A-C.

Parameter
A
B
C

λmax, nm
510
521
726
Beer's conc. Range (μg mL-1)
0.5–8.0
1.0–10
2.0–18
Ringbom conc. Range (μg mL-1)
0.85–7.5
2.0–8.5
3.0–16.5
Detection limits (μg mL-1)
0.065
0.104
0.228
Quantification limit (μg mL-1)
0.217
0.347
0.76
Molar absorpitivity × 10 4(L mol-1 cm-1)
1.812
1.876
1.039
Sandell sensitivity (ng cm-2)
15.86
15.32
27.66
Regression equation a



Sy/x
0.202
0.285
0.246
Intercept
0.0078
- 0.0018
0.0011
Sa
0.142
0.201
0.2007
± tSa
0.365
0.517
0.516
Slope
0.0582
0.066
0.036
Sb
0.0285
0.0365
0.018
± tSb
0.0733
0.094
0.0462
Correlation coefficient (r)
0.9999
0.9999
0.9997
Mean ± SD%
99.87 ± 0.659
100.21 ± 0.727
99.875 ± 0.759
RSD%
0.66
0.73
0.76
Variance
0.434
0.528
0.576
SE
0.269
0.297
0.31
Student, s t-valueb (2.571)
1.16
0.323
1.07
Variance ratio F-test b (6.256)
1.06
1.29
1.406

a A = a + b c, where c is the concentration in μg mL-1.

b The theoretical t- and F-values, 2.571 and 6.256, respectively for five degree of freedom at 95% confidence level.

Gouda and Hassan Chemistry Central Journal 2008 2:7   doi:10.1186/1752-153X-2-7