Osmo Mäkitie

Analysis, storage stability and reference values for urinary chromium and nickel

SummarySimple direct dilution methods are described for the analysis of urinary chromium and nickel with electrothermal atomic absorption spectrometry. The day-to-day variation of the methods is in the order of 5%, and the detection limits 20 and 0.1 nmol/l (1.2 and 0.0052 μg/l) for urinary nickel and chromium, respectively. At levels corresponding to occupational exposures, both metals are stable (within 20%) in urine specimens in the refrigerator for the least ten months. The stability does not require acidification. Geometric mean values for urinary nickel and chromium in the non exposed population in Finland (n = 299 and 155) are 70 and 1.5 nmol/l (4.8 and 0.078 μg/l), and the upper 95% confidence limits from a log-normal distribution, are 170 and 11 nmol/l(10 and 0.57 μg/l), respectively.

Complex formation between aluminium and 3-hydroxy-7-sulpho-2-naphthoic acid Potentiometric, absorption-spectrophotometric and spectrofluorometric studies in aqueous solution.

The formation of chelates between aluminium(III) and 3-hydroxy-7-sulpho-2-naphthoic acid has been studied in aqueous solutions of various ionic strengths, at 298 K. The stability constants of AlL, AlL(2) and AlL(3) and the protonation constants of the ligand, obtained by potentiometry with the glass electrode, are compared with values found by absorption and fluorescence spectrophotometric methods.

Absorption spectra of the nitrosonaphtholsulphonic acid complexes formed with iron(II)

SummaryA spectrophotometric study was made of the reactions of iron(II) with nine differento-nitrosonaphtholsulphonates in aqueous solution. The study shows that the green complexes formed by 1-nitroso-2-naphthol-6-sulphonate, 2-nitroso-1-naphthol-4-sulphonate, 2-nitroso-1-naphthol-6-sulphonate, and l-nitroso-2-naphthol-7-sulphonate with iron (II) have slightly higher molar absorptivities than the iron complex formed with the more popular reagent 1-nitroso-2-naphthol-3,6-disodium sulphonate (nitroso-R salt).ZusammenfassungDie Reaktionen von Eisen(II) mit neun verschiedeneno-Nitrosonaphtholsulfonaten in wäßiger Losung wurden spektrophotometrisch untersucht. Daraus ergab sich, daß die grünen Komplexverbindungen von l-Nitroso-2-naphthol-6-sulfonat, 2-Nitroso-1-naphthol-4-sulfonat, 2-Nitroso-1-naphthol-6-sulfonat und 1-Nitroso-2-naphthol-7-sulfonat mit Eisen(II) eine etwas stärkere molare Absorption ergeben als die Eisenkomplexe mit dem gebräuchlichen Reagens 1-Nitroso-2-naphthol-3,6-dinatriumsulfonat (Nitroso-R-Salz).

Absorption spectra of chelates of nitrosonaptholsulphonic acids with vanadaium(IV)

The absorption spectra of chelates formed by oxovanadium(IV) with five different o-nitro-sonaphtholsulphonic acids in aqueous solution are presented. All the ligands studied, 1-nitroso-2-naphthol-3,6-disulphonate (Nitroso-R salt), 2-nitroso-1-naphthol-4-sulphonate, 2-nitroso-1-naphthol-5-sulphonate, 2-nitroso-1-naphthol-8-sulphonate and 2-nitroso-1-naphthol-4,6-disulphonate, form red-brown vanadium(IV) chelates in acid solution. Values of the first Stability constants of the complexes are reported.