Determination of Metals in Natural Waters by Inductively Coupled Plasma Optical Emission Spectroscopy after Preconcentration on Silica Sequentially Coated with Layers of Polyhexamethylene Guanidinium and Sulphonated Nitrosonaphthols

Table 8

The results of ICP–OES determination of metals in natural waters (sample volume 100 mL acidified with 5 mL of 1 М HNO₃).

Metal	SiO2-PHMG-NRS				SiO2-PHMG-NNS
	Added, ng mL^−1	Found, ng mL^−1	Added, ng mL^−1	Found, ng mL^−1	Added, ng mL^−1	Found, ng mL^−1	Added, ng mL^−1	Found, ng mL^−1
	Sample 1		Sample 2		Sample 2		Sample 3
Cu(II)	-; 5.0	0.34±0.01; 5.37±0.05	-; 5.0	2.32±0.04; 7.33±0.07	-; 5.0	2.28±0.04; 7.26±0.07	-; 5.0	0.97±0.01; 5.99±0.06
Fe(III)	-; 5.0	0.72±0.01; 5.72±0.05	-; 5.0	1.69±0.03; 6.65±0.06	-; 5.0	1.71±0.03; 6.69±0.06	-; 5.0	10.7±0.1; 15.7±0.1
Ni(II)	-; 2.0	0.21±0.01; 2.19±0.03	-; 2.0	0.60±0.02; 2.58±0.03	-; 2.0	0.56±0.02; 2.57±0.03	-; 2.0	2.85±0.04; 4.82±0.04
Al(III)	-; 2.0	2.44±0.04; 4.43±0.04	-; 2.0	4.02±0.04; 6.01±0.06	-; 2.0	3.99±0.04; 6.02±0.06	-; 2.0	7.33±0.08; 9.40±0.10
Zn(II)	-; 2.0	1.62±0.03; 3.60±0.04	-; 2.0	2.56±0.04; 4.52±0.05	-; 2.0	2.49±0.04; 4.52±0.05	-; 2.0	5.05±0.05; 7.02±0.07
Pb(II)	-	ND	-	0.20±0. 02	-	0.22±0.02	-	0.48±0.03
	2.0	2.03±0.04	2.0	2.23±0.04	2.0	2.24±0.04	2.0	2.50±0.04

(), - average for five determinations, - standard deviation, ND – non-detected.