Table 4.

Results of the TBZ determination in aqueous samples obtained using direct potentiometry and the Gran method ¹.

TBZ Added (M)	TBZ Found (M) ± SD		Recovery (%)
	Direct Potentiometry	Gran Method	Direct Potentiometry	Gran Method
5.00 × 10−4	4.74 × 10−4 ± 4.75 × 10−6	4.96 × 10−4 ± 5.30 × 10−6	94.8	99.2
1.00 × 10−4	1.08 × 10−4 ± 7.23 × 10−6	1.03 × 10−4 ± 1.45 × 10−6	108.0	103.0
5.00 × 10−5	5.18 × 10−5 ± 5.28 × 10−7	5.20 × 10−5 ± 8.06 × 10−7	103.6	104.0
1.00 × 10−5	1.05 × 10−5 ± 6.39 × 10−7	1.13 × 10−5 ± 4.88 × 10−7	105.0	113.0
5.00 × 10−6	4.09 × 10−6 ± 1.85 × 10−7	5.60 × 10−6 ± 2.36 × 10−7	81.8	112.0

¹ Average of three determinations.