Table 2 Summary of data obtained from method validation

System suitability

%RSD for peak area response (n = 6)

Day-1: 1.6%

Day-2: 0.69%

Specificity

Interference from blank

No interference

Sensitivity

Concentration

LOD—0.62 ppm

LOQ—1.02 ppm

S/N for LOD solution should be > 3:1

4:1

S/N for LOQ solution should be > 10:1

15:1

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

2.58

Linearity

Range

1.02–50 ppm

Calibration Equation

y = 297x + 770.9

r²

0.9997

Residual plots

Random scatter

Precision

Average recovery (n = 6) from the spiked samples performed at 100% level; RSD should be ≤ 10.0%

93.6%; 5.4%

Accuracy

Average recovery (n = 3) from the spiked samples performed at 5 levels—LOQ—200%; RSD should be ≤ 10.0%

LOQ—90.3%; 7.2%

50%–90.9%; 6.5%

100%–95.8%; 1.5%

150%–105.3%; 1.9%

200%–102.6%; 1.1%

Intermediate precision (Analyst 2)

Average recovery (n = 6) from the spiked samples performed at 100% level; RSD should be ≤ 10.0%

96.9%; 3.6%

Solution stability

Standard and 100% spiked solution stored at ambient laboratory conditions (25 ± 5 °C) and refrigerated conditions

(2–8 °C) were studied for 48 h

Stable for 48 h

Robustness

RSD (%) for peak area response (n = 6) with 0.8 flow rate

%Recovery (n = 3) for 100% spiked solution with 0.8 flow rate

2.4%

95.6%

RSD (%) for peak area response (n = 6) with 1.2 flow rate

%Recovery (n = 3) for 100% spiked solution with 1.2 flow rate

1.8%

91.4%

RSD (%) for peak area response (n = 6) with 1.3 mL/min gas flow

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

5.3%

102.8%

RSD (%) for peak area response (n = 6) with 1.8 mL/min gas flow

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

2.2%

93.5%