Showing papers on "Color reaction published in 1969"
TL;DR: The inhibition of the indophenol reaction by amino acids has been found to be reversed by increased nitroprusside levels in assay mixtures, and attention must be given to the control of their effects on the color reaction.
78 citations
TL;DR: In this paper, the phopholipids of erythrocytes were separated by one-dimensional thin-layer chromatography and detemined quantitatively by the molybdenum blue method in the presence of Silica gel HR.
27 citations
TL;DR: Cupric chloride-triphenylphosphine complex reacts with riboflavin in alkaline medium giving an orange color having maximum absorbance at 460–465 nm and 1μg/ml as visual limit of identification.
Abstract: Cupric chloride-triphenylphosphine complex reacts with riboflavin in alkaline medium giving an orange color having maximum absorbance at 460–465 nm and 1μg/ml as visual limit of identification. This color reaction has been utilized for the spectrophotometric determination of riboflavin from pharmaceutical preparations in minute quantities. The reaction is specific for riboflavin and does not require stringent conditions. The maximum tolerable amount of other vitamins, sugars and amino acids during determination of riboflavin is reported.
11 citations
8 citations
TL;DR: In this article, a violet chelate (λmax540 mμ) with pyrogallol red at pH 4.4 was established by the continuous variation and mole ratio methods using absorbance data.
7 citations
TL;DR: Isonic acid hydrazide reacts with catechol in alkaline medium to give a pinkish-orange color which obeys Beer's law as discussed by the authors, and is used for its determination in blood or urine.
Abstract: Isonicotinic acid hydrazide reacts with catechol in alkaline medium to give a pinkish-orange color which obeys Beer's law. This color reaction is specific for isonicotinic acid hydrazide and is used for its determination in blood or urine. The visual limit of identification is 1 μg/ml.
4 citations
TL;DR: In this paper, a spectrophotometric method for determination of beryllium inμg quantities is described which is based on color reaction between beryellium and rufigallol having maximum absorption at 530 nm.
Abstract: A spectrophotometric method for determination of beryllium inμg quantities is described which is based on color reaction between beryllium and rufigallol having maximum absorption at 530 nm. Comparing various solvents, the suitable medium found is DMSO-H2O (3 ∶ 2). Interference of Al, Zr, Th, Hf and many other cations have been removed by solvent extraction of their oxinates with chloroform.
3 citations
TL;DR: In this paper, a color reaction was developed for Spectrophotometric determination of manganese in minute quantities and the maximum tolerable limit of other cations and anions was reported.
Abstract: Manganese solution in sodium hydroxide when mixed with brucine followed by HCl produces pink color having 1μg/ml as visual limit of identification and maximum absorbance at 475 nm. This color reaction has been developed for the Spectrophotometric determination of manganese in minute quantities. The maximum tolerable limit of other cations and anions is reported.
2 citations
TL;DR: In this article, a Spectrophotometric method for the determination of p-phenylenediamine in hair dyes is described, which obeys Beer's law (1 to 10μg/ml).
Abstract: Cupric chloride-triphenylphosphine complex gives red color witho-phenylenediamine having maximum absorption at 505–520 nm and 0.5μg/ml as visual limit of identification. The reaction is specific foro-phenylenediamine and obeys Beer's law (1 to 10μg/ml). This reaction provides the basis of a new method for the Spectrophotometric determination ofo-phenylenediamine inμg quantities. Ruthenium trichloride-triphenylphosphine complex gives blue color withp-phenylenediamine having maximum absorption at 580 nm and 2μg/ml as visual limit of identification. On the basis of this color reaction a Spectrophotometric method for the determination ofp-phenylenediamine in hair dyes is described. The recovery of the dye from commercial preparations is better than 97%. Other organic compounds do not interfere.
1 citations
TL;DR: The uranyl-alizarin fluorine blue chelate complex showed an absorption peak at 560 nm, 30 nm higher than that of any other single metal complex of the reagent.
Abstract: The uranyl-alizarin fluorine blue chelate complex shows an absorption peak at 560 nm, 30 nm higher than that of any other single metal complex of the reagent. The complex shows, at pH 4.5, a conditional stability constant of 2.3 × 106 litres mole−1 and molar absorptivity of 4100 litres mole−1 cm−1. Study of the feasibility of using this reaction for the photometric determination of Uo2 +2 in both one and two liquid phase systems reveals serious interference from other metal ions.
1 citations
TL;DR: The colour reaction described in this paper produces conclusive positive and negative results for the methacrylate and acrylate esters, respectively, and is applicable to other compounds examined.
TL;DR: In this article, a colorimetric method for the determination of m-aminophenol in small quantities was proposed, where the color reaction is specific form-aminopropol; o-, and p-aminopharmol do not interfere if their amount does not exceed 10 and 70% respectively.
Abstract: Potassium iodate reacts withm-aminophenol in presence of sulfuric acid to give pink violet color having 5μg as visual limit of identification. The color reaction is specific form-aminophenol;o-, andp-aminophenol do not interfere if their amount does not exceed 10 and 70% respectively. This provides a new colorimetric method for the determination ofm-aminophenol in small quantities.
TL;DR: In this paper, a photometric method for the determination of α-ketoglutaric acid is presented, which is based on the colour reaction of α -ketoglutsurphanilic acid in a sodium hydroxide solution with diazotized sulphanilic acids in the presence of sodium sulphite and sodium hypophosphite.