New simple spectrophotometric method for the specification of silver (i) in oil-water samples

Abstract

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.

Surfactant assisted spectrophotometric determination of copper(II), and mercury(II) in real samples using 2- amino-4-((4- nitrophenyl)diazenyl)pyridine-3-ol

“…Some types of mercury are relatively non-toxic and have been used to cure syphilis [29]. Some extractive spectrophotometric determinations of the investigated metals, such as naphthazarin (5,8-dihydroxy-1,4-naphthoquinone; Naph) [30], 1-[2-(allylamino)-1-methylethyl] NPAS [31], chloro-(phenyl) glyoxime [33], benzildithiosemi carbazone [34], thiomichlersketone [35], and 4,5,6-trihydroxyhexane-1,2-diylidene)bis(N-phenylhydrazinecarbothioamide) [36]. To detect Hg(II), 1,5-diphenylthiocarbazone (dithizone) [37], azathia-crown ether dye [38], Thio-Michler's Ketone [39], 2-[(2-sulfanylphenyl) ethanimidoyl]phenol [40], 6-hydroxy-3-(2-oxoindolin-3ylideneamino)-2-thioxo-2H-1,3-thiazin-4(3H)-one [41] and 2-Acetylpyridine thiosemicarbazone [42].…”