Development of Flow Injection Spectrophotometric Method for 1-Napthylthiourea Using Sodium Nitrite and Sulphanilic Acid Diazotization Reaction

Table 3

Percent recovery of ANTU in spiked natural water samples ().

Sample matrix	Spiked (mg/L)	Proposed method		HPLC method [15]
		Found (mg/L)	Recovered (%)	Found (mg/L)	Recovered (%)
Tap water	0.50	0.49 ± 0.012	98 ± 2.5	0.505 ± 0.011	101 ± 2.2
	1.00	0.93 ± 0.018	93 ± 1.9	1.02 ± 0.032	102 ± 3.1
	1.50	1.44 ± 0.040	96 ± 2.8	1.48 ± 0.027	99 ± 1.8
Irrigation water	1.00	1.03 ± 0.022	103 ± 2.1	1.10 ± 0.033	110 ± 3.0
	2.00	2.09 ± 0.050	105 ± 2.4	1.92 ± 0.063	96 ± 3.3
	3.00	3.12 ± 0.097	104 ± 3.1	2.81 ± 0.048	94 ± 1.7
Lake water	1.00	0.97 ± 0.032	97 ± 3.3	1.06 ± 0.021	106 ± 2.0
	2.00	2.07 ± 0.066	103.5 ± 3.2	1.96 ± 0.031	98 ± 1.6
	3.00	3.21 ± 0.051	107 ± 1.6	3.13 ± 0.10	104 ± 3.2

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