Table 3. Analysis of Tetrahydrozoline in Eye Drop Solution and Biological Fluids.

sample	taken(μg mL–1)	found*(μg mL–1)	bias%	recovery (%)	pharmacopoeia [18]
VISINE	5	5.03	0.50	100.50	100.80
	15	14.95	0.33	99.67	100.20
	30	30.07	0.23	100.23	99.40
	50	50.30	0.60	100.60	99.70
mean				100.25	100.03
variance				0.18	0.38
observations				4	4
df				3	3
t-test	0.61
F	2.14
t critical two-tail	2.45

sample	add(μg mL–1)	found*(μg mL–1)	bias%	recovery (%)	pharmacopoeia [18]
spiked urine	10	10.05	0.50	100.50	100.70
	20	20.12	0.33	100.60	99.40
	40	39.70	0.23	99.25	100.10
mean				100.12	100.07
variance				0.57	0.42
observations				3	3
df				2	2
t-test	0.17
F	1.33
t critical two-tail	2.78
F critical one-tail	19.00

sample	added(ng mL–1)	found(ng mL–1)	recovery (%)	SD	% RSD
plasma	100	100.5	100.50	0.120	1.34
	220	218	99.09	0.085	1.22
	350	352	100.57	0.055	0.95

^*Average of five replicates measurement