First Derivative Zero-Crossing Spectroscopic Method Lab Report

6. FIRST DERIVATIVE ZERO CROSSING METHOD
6.1. ABSTRACT:
Simple, specific, accurate and precise 1st order derivative zero-crossing spectroscopic method was developed for simultaneous determination of PHENYLEPHRINE and EBASTINE from their binary mixture. In this 1st derivative zero-crossing spectroscopic method the amplitudes of the 1st order derivative of the spectra of the binary mixture containing PHE and EBS were measured at 252.2 nm (zero crossing of EBS) for determination of PHE and at 274.8 nm (zero crossing of PHE) for the determination of EBS. Pharmaceutical formulations were successfully analyzed using the developed method.
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6.2. EXPERIMENTAL:
 Apparatus and Software:
Shimadzu UV-1800 double beam spectrophotometer connected to a computer
The experiment was repeated 3 times in a day for intra-day and on 3 different days for inter-day precision. The average % RSD of intra-day and inter-day measurements of PHE was found to be 1.20% and 1.20% respectively. For EBS % RSD of intra-day and inter-day measurements was found to be 1.77 % and 0.813 % respectively. The values confirmed the precision of the method.

Table 6.2: Intra-day precision for determination of PHE
PHE
µg/ml Absorbance at 252.2 nm 1 2 3 Mean %RSD
5 0.011 0.011 0.011 0.011 1.931
10 0.024 0.024 0.024 0.024 1.211
15 0.035 0.035 0.036 0.035 1.428
20 0.045 0.046 0.047 0.046 1.672
25 0.057 0.058 0.059 0.058 1.724
Average % RSD 1.215

Table 6.3: Intra-day precision for determination of EBS
EBS
µg/ml Absorbance at 274.8 nm 1 2 3 Mean %RSD
5 0.052 0.051 0.053 0.052 1.923
10 0.099 0.101 0.103 0.101 1.980
15 0.153 0.155 0.157 0.155 1.290
20 0.203 0.206 0.210 0.206 1.702
25 0.255 0.258 0.265 0.259 1.978
Average % RSD 1.77

Table 6.4: Inter-day precision for determination of PHE
PHE
µg/ml Absorbance at 252.2 nm 1 2 3 Mean %RSD
5 0.012 0.012 0.012 0.012