Separation and Determination of Fe(III) and Fe(II) in Natural and Waste Waters Using Silica Gel Sequentially Modified with Polyhexamethylene Guanidine and Tiron

Table 3

Results of Fe(III) and Fe(II) determination in well waters ().

Sample	Found, μg mL^−1						Total Fe,; μg mL^−1
	Fe(III)			Fe(II)
	0.5 h	6 h	24 h	0.5 h	6 h	24 h
Well water number 1	0	0.14		0.18	0.05	0	0.18
Well water number 2	0.1	1.0		1.7	0.6	0.1	1.8

(III) hydroxide precipitation.