Table 2 Method validation data summary

System suitability

RSD (%) for peak area response (n = 6)

1.27%

0.28%

Cumulative RSD (%) for peak area response (all injections)

1.10%

3.15%

System suitability (for Intermediate precision)

RSD (%) for peak area response (n = 6)

0.36%

1.44%

Cumulative RSD (%) for peak area response (all injections)

0.83%

1.43%

Specificity

Blank interference and USP Resolution

No blank interference, 2-BE and 2-BEM are well resolved from residual solvent and matrix peaks

Sensitivity

Concentration

LOD—8.1 ppm

LOQ—24.3 ppm

LOD—8.0 ppm

LOQ—24.1 ppm

S/N for LOD solution should be > 3:1

4:1

3:1

S/N for LOQ solution should be > 10:1

13:1

11:1

RSD (%) for six replicate injections of LOQ solution should be ≤ 15.0%

2.61%

1.09%

Linearity

Range

24.1–3013.5 ppm

25.1–301.4 ppm

Calibration Equation

y = 0.7513 x − 0.0538

y = 0.8364x − 0.1050

r²

0.9999

0.9999

Residual plots

Random scatter

Random scatter

Accuracy

Average recovery (n = 3) from the spiked samples performed at 5 levels should be between 80 and 100%; RSD (%) should be ≤ 10.0%

LOQ—95.8%; 4.75%

50–95.9%; 2.16%

100–99.8%; 3.60%

150–94.5%; 1.01%

300–101.1%; 0.29%

LOQ—93.5%; 1.27%

50–90.6%; 4.50%

100–104.4%; 0.67%

150–95.7%; 0.40%

300–96.7%; 0.43%

Precision

RSD (%) for six preparations at 100% spike level should be ≤ 10.0%

1.39%

2.73%

Intermediate Precision

RSD (%) for six preparations at 100% spike level should be ≤ 10.0%

1.33%

2.35%

Robustness 0.9 mL min⁻¹ Flow

RSD (%) for peak area response (n = 6)

%Recovery (n = 3) for 100% spiked solution

0.39%

97.6%

1.70%

93.5%

Robustness 1.1 mL min⁻¹ Flow

RSD (%) for peak area response (n = 6)

%Recovery (n = 3) for 100% spiked solution

1.04%

91.3%

0.95%

96.9%

Robustness 45° Oven Temp

RSD (%) for peak area response (n = 6)

%Recovery (n = 3) for 100% spiked solution

0.47%

93.7%

1.35%

94.9%

Robustness 55° Oven Temp

RSD (%) for peak area response (n = 6)

%Recovery (n = 3) for 100% spiked solution

1.02%

95.9%

0.71%

95.3%