Photometric determination

Alexiev A, Rubio S, Deyanova M, Stoyanova A, Sicilia D and Perez-Bendito D 1994 Improved catalytic photometric determination of iron (III) in cetylpyridinium premicellar aggregates Anal. Chim. Acta 295 211-19... 

For colorimetric or gravimetric determination l-nitroso-2-naphthol can be used. For chromatographic ion exchange (qv), cobalt is isolated as the nitroso-(R)-salt complex. The cyanate complex is used for photometric determination and the thiocyanate for colorimetry. A rapid chemical analysis of... 

SOME FEATURES OF AN INDIRECT SORPTION-PHOTOMETRIC DETERMINATION OF NONIONOGENIC SURFACTANTS... 

The well-known reaction of Ni(II) with dimethylglyoxime (H Dm) in alkaline medium under the influence of such oxidants as persulphate and iodine is widely used for the photometric determination of nickel. The red product (RP) of this reaction is used for this purpose. However, the nature of this red compound has not been defined yet. Using of peroxyacids makes it possible to obtain additional data concerning the conditions and mechanism of generation of RP as well as to improve the metrological pai ameters of the method. 

PHOTOMETRIC DETERMINATION OF ACIDIC IMPURITIES IN OILS AND ORGANIC LIQUIDS WITH THE USE OF THE ION PAIR OF TRINONYLOCTADECYLAMMONIUM AND BROMOTHYMOL BLUE AS THE COLORED REAGENT... 

Development of extraction-free photometric procedures for the determination of traces of metals for which hygienic and environmental regulations have been established is an urgent problem. For solution of this problem we used as an organic reagent l-(2- pyridylazo)-naphtol-2 (PAN) which forms intensely coloured complex compounds with many metals and is frequently used for their extraction-photometric determination however these procedures did not find wide application in water analysis due to lack of selectivity and necessity of using organic solvents. 

As the result of the performed investigations was offered to make direct photometric determination of Nd microgram quantities in the presence of 500-fold and 1100-fold quantities of Mo and Pb correspondingly. The rare earth determination procedure involves sample dissolution in HCI, molybdenum reduction to Mo (V) by hydrazine and lead and Mo (V) masking by EDTA. The maximal colour development of Nd-arsenazo III complex was obtained at pH 2,7-2,8. The optimal condition of Nd determination that was established permit to estimate Nd without separation in solution after sample decomposition. Relative standard deviations at determination of 5-20 p.g of Nd from 0,1 g PbMoO are 0,1-0,03. The received data allow to use the offered procedure for solving of wide circle of analytical problems. 

So, extractive and photometric determination of 2,4-D with CV and also the test-scale for its semiquantitative determination with separation from instmmental basis are proposed. 

The method of extraction of Ru(III) from thiocyanate solutions by water soluble extractants in the presence of ammonium sulfate as salting out agent followed by photometric determination of it in extract has been elaborated. 

Method of Rh(III) - Ru(III) separation and isolation them from rai e and nonferrous metals based on formation of different charged complexes with varied stability has been proposed. Possibility of sepai ation of Ru(III), Rh(III), Pd(II), Pt(II) by water-soluble extractants from concentrated thiocyanate solutions has been displayed. Accelerated procedures of extraction-photometric determination of Rh(III), Ru(III) in solutions and waste products, which ai e chai acterized by high selectivity, availability, usage of non-toxic extractants have been worked out. 

Brombenztiazo (BBT) is known to be one of the best reagents for extraction-photometric determination of cadmium(II). The reagent also fonus complexes with Co(II), Cu(II), Fe(II), Ni(II), Zn(II). The aim of this work was to develop a solid-phase reagent on the base of BBT immobilized on silica gel for sorption-spectroscopic and visual test determination of Cadmium, and also for soi ption-atomic-adsoi ption determination of total heavy metals contents in natural waters. 

Among the many, such combination method, which allows to combine the sorption concentration and the subsequent photometrical determination in solid phase, as solid-phase spectrophotometry (SPS), proves to be very effective in the analysis. 

The optical train employed for photometric determinations of fluorescence depends on the problem involved. A spectral resolution of the emitted fluorescence is not necessary for quantitative determinations. The optical train sketched in Figure 22B can, therefore, be employed. If the fluorescence spectrum is to be determined the fluorescent light has to be analyzed into its component parts before reaching the detector (Fig. 28). A mercury or xenon lamp is used for excitation in such cases. 

In situ quantitation The photometric determination was made in reflectance mode at 2 = 550 nm (Fig. 1). 

In situ quantitation The absorption-photometric determination in a reflectance mode was performed at A = 330 nm (detection limit ca. 40 ng per chromatogram zone). The fluorimetric analysis was carried out at =313 nm and An > 560 nm (detection limits ca. 10 ng per chromatogram zone) (Fig. 1). 

Tamaoku and colleagues presented an efficient enzymatic photometric determination of hydrogen peroxide ffiat is essentially a color reaction resulting from the oxidative condensation of A/-ethyl-A/-(2-hydroxy-3-sulfopropyl)aniline derivatives wiffi 4-aminoantipyrine in the presence of hydrogen peroxide and peroxidase (82CPB2492). A similar calorimetric detection of hydrogen peroxide has been patented (83GEP3301470). 

The interaction of irritating substance with the cell membrane can also be measured if red blood cells are used. With a photometric determination the hemolysis (L f) and denaturation (D f) is measured. The ratio LID is an expression for the dermatological compatibility. Low LID figures describe a certain irritation, high LID figures describe a substance as mild. Results found for the... 

Vol. 3 Photometric Determination of Traces of Metals. Fourth Edition Part I General Aspects. By E. B. Sandell and Hiroshi Onishi Part IIA Individual Metals, Aluminum to Lithium. By Hiroshi Onishi Part IIB Individual Metals, Magnesium to Zirconium. By Hiroshi Onishi Vol. 4 Organic Reagents Used in Gravimetric and Volumetric Analysis. By John F. Flagg (out ofprint)... 

Berges, D., G. Schmitt et al. (1959). The effects of helenien and vitamin A on the primary sight process. III. A flame photometric determination of the potassium and sodium content of the retina (German). Z. Biol. Ill 220-227. 

Based on the formation of a yellow product of niclosamide in a 0.1 N NaOH medium, Kokovkin-Shcherbak and Tiraspol skaya [57] improved the photometric determination of the drug using differential photocolorimetry. Three independent factors were taken into account the comparative solution, the solution to be analyzed, and concentration of NaOH. 

Budantsev, A.Yu. (2004). Photometric determination of compounds in paper matrices using digital imaging technique and transmitted light images. Journal of Analytical Chemistry (Russian) 59 791-795. 

In this development of a flow injection method for the determination of nitrate andnitrite, Anderson [168] chose the Shinn [155] method to reduce nitrate and nitrite because of its high sensitivity and relative freedom from interferences. Anderson [168] used flow injection in the photometric determination of nitrite and nitrate with sulfanilamide and N-( 1-naphthyl) ethylenediamine as reagents, as discussed next. The detection limit is 0.05 xm for nitrite and 0.1 xm for nitrate at a total sample volume of 200 iL. Up to 30 samples can be analysed per hour with relative precision of about 1%. 

Various approaches to the analysis of dissolved silicon have been tried. Most of them are based on the formation of /J-molybdosilic acid [ 199-203 ]. Dissolved silicon exists in seawater almost entirely as undissociated orthosilicic acid. This form and its dimer, termed reactive silicate , combine with molybdosilicic acid to form a- and /I-molybdosilicic acid [180]. The molybdosilicic acid can be reduced to molybdenum blue, which is determined photometrically [206]. The photometric determination of silicate as molybdenum blue is sufficiently sensitive for most seawater samples. It is amenable to automated analysis by segmented continuous flow analysers [206-208]. Most recent analyses of silicate in seawater have, therefore, used this chemistry. Furthermore, reactive silicate is probably the only silicon species in seawater that can be used by siliceous organisms [204]. 

Hicks and Riley [287] have described a method for determining the natural levels of nucleic acids in lake and seawaters, which involves preconcentration by adsorption onto a hydroxyapatite, elution of the nucleic acids, and then photometric determination of the ribose obtained from them by hydrolysis. 

The use of basic organic dyes for ion pair extraction-photometric determination has been described.87 After ammonia treatment, an orange-red color with CUS04 and H2O2 (Deniges) can be quantitated.88 A water insoluble violet complex (X max. 620 nm) with 2-picoline-Cu(II) has also been reported.89... 

---