Detection chromate

Silbert L, Ben Shlush I, Israel E, Porgador A, Kolusheva S, Jelinek R. Rapid chromatic detection of bacteria by use of a new biomimetic polymer sensor. Appl Environ Microbiol 2006 72 7339-7344. 

Scheme 5 Schematic representation of the mechanism of chromatic detection hy chemo-sensor 29-PV toward inorganic phosphate. The effective displacement of PV with phosphate anion at the binding site results in color change of the solution from blue to yellow...

Figure 11 (Left) Scheme of the polymerized bilayer assembly. The blue phase polydiyacetylene chromatic detection element is deposited over a support monolayer. The polydiacetylene chain Is asymmetrically substituted with urethane side groups partially terminated with receptor-binding ligands. (Right) Absorption spectrum of the blue and red phase PDA with a schematic representation of their chain with (red phase) and without (blue phase) influenza virus attached. Adapted figures with permission from D.H. Charych, J.O. Nagy, W. Spevak, and M.D. Bednarski, Sc/ence 261, 585 (1993), Figure 2 and 3. Copyright 1993 AAAS.

DETECTION OF CHROMATE DEFECTS IN Cr(III) CONTAINING DIPHOSPHATES BY LUMINESCENCE TECHNIQUE... 

Measurement over long view path (up to 100 km) with suitable illumination and target, contrast transmittance, total extinction, and chromaticity over sight path can be determined includes scattering and absorption from all sources can detect plume blight automated... 

Chloride. The chloride concentration is determined by titration with silver nitrate solution. This causes the chloride to be removed from the solution as AgCl, a white precipitate. The endpoint of the titration is detected using a potassium chromate indicator. The excess Ag present after all Cl" has been removed from solution reacts with the chromate to form Ag CrO, an orange-red precipitate. 

Figure 3 Gradient separation of anions using suppressed conductivity detection. Column 0.4 x 15 cm AS5A, 5 p latex-coated resin (Dionex). Eluent 750 pM NaOH, 0-5 min., then to 85 mM NaOH in 30 min. Flow 1 ml/min. 1 fluoride, 2 a-hydrox-ybutyrate, 3 acetate, 4 glycolate, 5 butyrate, 6 gluconate, 7 a-hydroxyvalerate, 8 formate, 9 valerate, 10 pyruvate, 11 monochloroacetate, 12 bromate, 13 chloride, 14 galacturonate, 15 nitrite, 16 glucuronate, 17 dichloroacetate, 18 trifluoroacetate, 19 phosphite, 20 selenite, 21 bromide, 22 nitrate, 23 sulfate, 24 oxalate, 25 selenate, 26 a-ketoglutarate, 27 fumarate, 28 phthalate, 29 oxalacetate, 30 phosphate, 31 arsenate, 32 chromate, 33 citrate, 34 isocitrate, 35 ds-aconitate, 36 trans-aconitate. (Reproduced with permission of Elsevier Science from Rocklin, R. D., Pohl, C. A., and Schibler, J. A., /. Chromatogr., 411, 107, 1987.)...

Figure 10 Capillary ion analysis of 30 anions 1 = thiosulfate, 2 = bromide, 3 = chloride, 4 = sulfate, 5 = nitrite, 6 = nitrate, 7 = molybdate, 8 = azide, 9 = tungstate, 10 = monofluorophosphate, 11 = chlorate, 12 = citrate, 13 = fluoride, 14 = formate, 15 = phosphate, 16 = phosphite, 17 = chlorite, 18 = galactarate, 19 = carbonate, 20 = acetate, 21 = ethanesulphonate, 22 = propionate, 23 = propanesulphonate, 24 = butyrate, 25 = butanesulphonate, 26 = valerate, 27 = benzoate, 28 = D-glutamate, 29 = pentane-sulphonate and 30 = D-gluconate. Experimental conditions fused silica capillary, 60 cm (Ld 52 cm) x 50 p i.d., voltage 30 kV, indirect UV detection at 254 nm, 5 mM chromate, 0.5 mM NICE-Pak OFM Anion-BT, adjusted to pH 8.0, with 100 mM NaOH. (From Jones, W. R. and Jandik, R, /. Chromatogr., 546, 445,1991. With permission.)...

Nestmann ER, Matula TI, Douglas GR, et al. 1979. Detection of the mutagenic activity of lead chromate using a battery of microbial tests. Mut Res 66 357-365. 

Tarantilis, P. A., G. Tsoupras et al. (1995). Determination of saffron (Crocus sativa L.) components in crude plant extracts using hihg-performance liquid chromatography-UV-visible photodiode array detection-mass spectrometry. J. Chromat. A 699 107-118. 

Aliphatic amines have been determined by a number of methods. Batley et al. [290] extracted the amines into chloroform as ion-association complexes with chromate, then determined the chromium in the complex colorimetri-cally with diphenylcarbazide. The chromium might also be determined, with fewer steps, by atomic absorption. With the colorimetric method, the limit of detection of a commercial tertiary amine mixture was 15ppb. The sensitivity was extended to 0.2 ppb by extracting into organic solvent the complex formed by the amine and Eosin Yellow. The concentration of the complex was measured fluorometrically. Gas chromatography, with the separations taking place on a modified carbon black column, was used by Di Corcia and Samperi [291] to measure aliphatic amines. 

The end points of precipitation titrations can be variously detected. An indicator exhibiting a pronounced colour change with the first excess of the titrant may be used. The Mohr method, involving the formation of red silver chromate with the appearance of an excess of silver ions, is an important example of this procedure, whilst the Volhard method, which uses the ferric thiocyanate colour as an indication of the presence of excess thiocyanate ions, is another. A series of indicators known as adsorption indicators have also been utilized. These consist of organic dyes such as fluorescein which are used in silver nitrate titrations. When the equivalence point is passed the excess silver ions are adsorbed on the precipitate to give a positively charged surface which attracts and adsorbs fluoresceinate ions. This adsorption is accompanied by the appearance of a red colour on the precipitate surface. Finally, the electroanalytical methods described in Chapter 6 may be used to scan the solution for metal ions. Table 5.12 includes some examples of substances determined by silver titrations and Table 5.13 some miscellaneous precipitation methods. Other examples have already been mentioned under complexometric titrations. 

Compared to flame excitation, random fluctuations in the intensity of emitted radiation from samples excited by arc and spark discharges are considerable. For this reason instantaneous measurements are not sufficiently reliable for analytical purposes and it is necessary to measure integrated intensities over periods of up to several minutes. Modern instruments will be computer controlled and fitted with VDUs. Computer-based data handling will enable qualitative analysis by sequential examination of the spectrum for elemental lines. Peak integration may be used for quantitative analysis and peak overlay routines for comparisons with standard spectra, detection of interferences and their correction (Figure 8.4). Alternatively an instrument fitted with a poly-chromator and which has a number of fixed channels (ca. 30) enables simultaneous measurements to be made. Such instruments are called direct reading spectrometers. 

Delonge, T. Fouckhardt, H., Integrated optical detection cell based on Bragg reflecting waveguides, J. Chromat. A 1995, 716, 135 139... 

Figure 9.26 Cr 2p spectra and negative SIMS spectra of two model catalysts and a blank reference. The blank (bottom) shows only Si,0, fragments on a chromium-loaded catalyst CriCf fragments appear after thermal activation (Ar/02). If desorption of chromium is made impossible (in oxygen-free argon), Cr2Or clusters can also be detected. In combination, this is strong evidence that chromate anchors to the silica surface as a monomer (courtesy of P.C. Thiine and R. Linke, Eindhoven).

Fig. 17.12. The determination of typical anions using indirect UV detection. Conditions 10 mM sodium chromate, 2.30 mM cetyltrimethylammonium bromide, 60 cm fused silica capillary (effective length 52 cm) x 75 pm I.D., injection 5 s at 35mbar, 20°C, -15 kV (reversed polarity) resulting in a current of approximately 30 pA, detection UV 254 nm.

Chromate, TTAB, borate CZE system with indirect detection Inorganic anions 52... 

FIGURE 9 Separation of chloride, sulfate, and nitrate at 40pg/mL with 5 mM chromate, 0.5 mM TTA-OH, 1.0 mM borate as BGE. Chlorate is used as internal standard. Linearity between I and 4pg/mL with an = 0.999 for all analytes. Indirect UV detection at 254nm (lOnm bandwidth). 

Adamantane carboxylic acids 13, CM-/3, Me-p A-reciprocal 66 indirect detection (sodium chromate)... 

Elemental composition Cu 64.18%, Cl 35.82%. Copper(I) chloride is dissolved in nitric acid, diluted appropriately and analyzed for copper by AA or ICP techniques or determined nondestructively by X-ray techniques (see Copper). For chloride analysis, a small amount of powdered material is dissolved in water and the aqueous solution titrated against a standard solution of silver nitrate using potassium chromate indicator. Alternatively, chloride ion in aqueous solution may be analyzed by ion chromatography or chloride ion-selective electrode. Although the compound is only sparingly soluble in water, detection limits in these analyses are in low ppm levels, and, therefore, dissolving 100 mg in a liter of water should be adequate to carry out aU analyses. 

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