Direct Determination of ECD in ECD Kit: A Solid Sample Quantitation Method for Active Pharmaceutical Ingredient in Drug Product
Table 5
Robustness study in the analysis of ECD.
Parameter
Standard curve of coal(1)
QCcoal (2)
Linear least squares regression equation
Correlation coefficient ()
Sulfur weight (%)
Recovery yield (%)(3)
Dosing time (sec)
90
Y = 1.544 × 10−6X + 3.394 × 10−3
0.9992
3.14 ± 0.06
102.36 ± 2.58
120
Y = 1.615 × 10−6X + 4.747 × 10−3
0.9993
3.13 ± 0.07
101.91 ± 2.30
150
Y = 1.604 × 10−6X + 7.508 × 10−4
0.9999
3.05 ± 0.10
99.17 ± 2.84
Temperature of combustion tube (°C)
1120
Y = 1.605 × 10−6X + 8.215 × 10−4
0.9997
3.13 ± 0.06
102.01 ± 1.85
1150
Y = 1.615 × 10−6X + 4.747 × 10−3
0.9993
3.13 ± 0.07
101.91 ± 2.30
1180
Y = 1.586 × 10−6X + 1.126 × 10−3
0.9985
3.03 ± 0.03
98.68 ± 1.14
Temperature of reduction tube (°C)
850
Y = 1.621 × 10−6X + 9.226 × 10−5
0.9997
3.12 ± 0.06
102.01 ± 1.75
900
Y = 1.615 × 10−6X + 4.747 × 10−3
0.9993
3.13 ± 0.07
101.91 ± 2.30
950
Y = 1.649 × 10−6X − 1.288 × 10−3
0.9996
3.00 ± 0.02
97.97 ± 0.87
(1)Standard curves were constructed by the coal concentration range of 1.01 to 3.49 mg. (2)Data are expressed as average ± SD, . (3)Recovery yield (%) = Sulfur(mg)exp/Sulfur(mg)nominal × 100%.
