A simple, highly selective and non-extractive spectrophotometric method for the specification of trace amounts silver (I) has been developed. In the water media 2,2’-di (2,3,4-trihydroxy-phenylazo) biphenyl reacts with the silver to give a highly absorbent greenish-yellow chelate in a molar ratio 2:1 (Ag:R). The reaction is instantaneous, the maximum absorption was obtained at 540 nm and remains stable for 24 hours. The average molar absorptivity and Sandell’s sensitivity were 4.3×104 l mol-1 cm-1 and 5.0 mkg cm-2 of silver (I), respectively. Linear calibration graphs were obtained for 0.1–30 mkgml−1 of silver (I), respectively. A large excess of over 30 cations, anions and complex agents do not interfere in the specification. The method is highly selective for silver and was successfully appliedin a number of oilwater samples. It has high precision and accuracy (s = ± 0.01 for 0.5 mkgl-1). Therefore, it may be used for monitoring to establish trace level of silver (I) in difficult matrices of oilwater samples.

It is shown that gold(III) with 2,2',3,4-tetrahydroxy-3'-sulpho-5'-chlorazobenzene (TSXAB) the rapid reacts in pH 5-6 acidic solution to form brownish-yellow complex and in pH 4-5 acidic solution to form brownish complexes in the presence of the cationic surfactantscetylpyridinium chloride (CPCl), cetylpyridinium bromide (CPBr) and cetyltrymethylammonium bromide (CTMABr). The absorption spectra of the Au(III)-TSXAB system is a curve with the maximum absorbance at 490 nm and molar absorption coefficient of 2.3 . 10 4 l mol −1 cm −1 in aqueous media. The absorption spectra of the Au(III)-TSXAB-CPCl, Au(III)-TSXAB-CPBr and Au(III)-TSXAB-CTMABr systems is a curves with the maximum absorbances at 520, 520 and 540 nm and molar absorption coefficients of 3.78 . 10 4 , 3.67 . 10 4 and 3.81 . 10 4 l mol −1 cm −1 in micellar media respectively. The absorbance was linear for 0.584-5.61 mkg/ml of Au(III) in the Au(III)-TSXAB-CPCl, Au(III)-TSXAB system and 0.428-6.362, 0.435-6.221, 0.436-6.832 mkg/ml of Au(III) in the Au(III)-TSXAB-CPCl, Au(III)-TSXAB-CPBr and Au(III)-TSXAB-CTMABr systems, respectively. The Sandell's sensitivity for Au(III) were found to be 7 mkg cm -2 in Au(III)-TSXAB system and 5, 6, 5 mkg/cm in the Au(III)-TSXAB-CPCl, Au(III)-TSXAB-CPBr, Au(III)-TSXAB-CTMABr systems. The proposed methods was successfully used in the determination of Au(III) in several synthetic mixtures. The relative standard deviation (n = 5) was (0-2.0)%, for Au(III) indicating that this methods are highly precise and reproducible. The results obtained agree well with synthetic mixture samples analyzed by inductively coupled plasma optical emission spectrometry.

A fairly simple, selective and non-extractive spectrophotometric method for the determination of trace amounts of silver (I) was developed and 2,2 ' ,3, suggested as a new analytical reagent for the direct non-extractive spectrophotometric determination of silver (I). In the aqueous medium TSNAB reacts with silver to give a highly orange absorbent chelate with a molar ratio of 1:2 (Ag: TSNAB). Note that the reaction is instantaneous and the maximum absorption was obtained at 490 nm that remains stable for 24 h. The average molar absorptivity and Sandell's sensitivity were found to be 1.37×10 4 l mol -1 cm -1 and 8.0 mkg cm -2 of silver(I) respectively. Linear calibration graphs were obtained for 0.864-5.184mkgml −1 of silver(I). A large excess of over 30 cations, anions and complexing agents impedes no determination. The non-extractive method is rather selective for silver(I) to have been successfully applied to synthetic mixtures.

A very simple, sensitive, highly selective and non-extractive spectrophotometric method for the determination of trace amounts of silver(I) has been developed. 2,2 ' -di(2,3,4-trihydroxyphenilazo)biphenil (DTFAB) has been proposed as a new analytical reagent for the direct non-extractive spectrophotometric determination of silver(I). In the water media DTFAB reacts with silver to give a highly absorbent greenish yellow chelate with a molar ratio 2:1 (Ag:DTFAB). The reaction was instantaneous and the maximum absorption was obtained at 540 nm and remains stable for 24 h. The average molar absorptivity and Sandell's sensitivity were found to be 4.3·10 4 l mol -1 cm -1 and 5.0 mkg/cm 2 of silver(I), respectively. Linear calibration graphs were obtained for 0.1-30 mkg/ml of silver(I). A large excess of over 30 cations, anions and complexing agents do not interfere in the determination. The method is highly selective for silver and was successfully applied to synthetic mixtures. The method has high precision and accuracy (s = ± 0.01 for 0.5 mkg/l).