Table 5.

Statistical comparison for the results obtained by the proposed HPLC method and the official method [1]

Parameter	Proposed method		Official method [1]
	PHE	IBU	PHE	IBU
Mean of recoveriesa	99.44	99.78	100.02	99.57
SD	1.38	1.27	0.85	1.09
Variance	1.92	0.13	0.73	1.19
N	5	5	5	5
Student’s t-test (2.30)b	0.78	0.24	–
F-test (6.38)b	2.60	0.11	–

^aAverage of three determinations

^bValues between parenthesis are corresponding to the theoretical values of t and F (P = 0.05)