Table 1.
Linearity range, limits of quantification (LOQ) and detection (LOD) parameters for the detection conditions of DPPH-R/DPPH-H.
| DAD nm | LOD µmol L−1 | LOQ µmol L−1 | Linearity Range: µmol L−1 | Linearity Equation: (y = ax + b) * | ||||
|---|---|---|---|---|---|---|---|---|
| a ± SD | b ± SD | R2 | F | se | ||||
| The detection conditions of DPPH-R in MeOH | ||||||||
| 330 350 517 |
25.6 26.9 37.2 |
77.4 81.5 112.7 |
70–490 70–490 70–630 |
9073.44 ± 224.42 5148.86 ± 134.11 4973.57 ± 142.24 |
−230,407.43 ± 70,255.84 −57,615.57 ± 41,983.95 −250,219.75 ± 56,030.77 |
0.997 0.997 0.994 |
1634.58 1473.95 1222.59 |
83,127.83 49,676.07 77,126.04 |
| The detection conditions of DPPH-R in presence of AO ** | ||||||||
| 330 517 |
6.4 9.5 |
19.3 28.9 |
3.5–315 17.5–315 |
5,700,012.9 ± 69,506.8 301,066.5 ± 4882.4 |
−4386.17 ± 10,996.12 −953.57 ± 871.17 |
0.992 0.998 |
6725.07 3802.36 |
27,621.50 1630.22 |
| The detection conditions of DPPH-H in presence of AO ** | ||||||||
| 350 517 |
6.4 19.2 |
19.5 58.1 |
7–315 28–315 |
501,769.22 ± 5957.58 122,833.91 ± 3820.14 |
88.77 ± 978.05 −926.77 ± 714.59 |
0.999 0.992 |
2260.64 1033.89 |
7093.61 1164.66 |
* The REGLINP function was used to calculate the statistics for a straight line using the least-squares method. The function returns the following parameters of the best-fit linear trend (y = ax + b): coefficient of determination (R2), Fisher F statistic (F), standard error of estimate (se), point of intersection (b ± SD), slope (a ± SD) with standard error values (SD) for constants. The measured parameters are the arithmetic mean of three independent determinations. ** Measurements were performed in excess of ascorbic acid after 15 min in a dark place. Conditions: 1 mL of 5 mM ascorbic acid dissolved in 80% (v/v) MeOH was mixed with 1 mL of DPPH-R in methanol at different concentrations. Measurements were performed in excess of ascorbic acid after 15 min in a dark place.