A comparison of two colorimetric procedures for the determination of serum glutamic oxaloacetic acid (SCOT) showed that both the dinitrophenylhydrazine and diazonium salt colorimetric assay procedures have good precision and reproducibility acceptable to most clinical laboratories. Babson’s diazonium salt procedure (3) definitely shows greater precision in the important borderline range of valu...

Colorimetric quantification of p-aminohippurate (PAH), which is helpful in assessment of renal function, is subject to interference from sulfa compounds such as sulfamethoxazole. We were unable to measure serum PAH in two patients receiving a trimethoprim-sulfamethoxazole combination because of interference by the latter with the colorimetric estimation. We found that isoamyl acetate removes su...

Hue plane preserving color correction (HPPCC), introduced by Andersen and Hardeberg [Proceedings of the 13th Color and Imaging Conference (CIC) (2005), pp. 141-146], maps device-dependent color values (RGB) to colorimetric color values (XYZ) using a set of linear transforms, realized by white point preserving 3×3 matrices, where each transform is learned and applied in a subregion of color spac...

Gold nanoparticles functionalized with thiolated oligonucleotides (Au-nanoprobes) have been used in a range of applications for the detection of bioanalytes of interest, from ions to proteins and DNA targets. These detection strategies are based on the unique optical properties of gold nanoparticles, in particular, the intense color that is subject to modulation by modification of the medium di...

One of the main factors limiting agricultural production in tropical climate regions is mainly related to the presence of exchangeable aluminum (Al) in highly weathered acid soils. Four methods of Al determination extracted with neutral 1 mol L KCl solution were evaluated: three colorimetric methods (aluminon plus ascorbic acid, and eriochrome cyanine R by FIA) and the usual titrimetric method ...

(1) Background: d-alanine-d-alanine ligase (DdlA), an effective target for drug development to combat against Mycobacterium tuberculosis (Mtb), which threatens human health globally, supplies a substrate of d-alanyl-d-alanine for peptidoglycan crosslinking by catalyzing the dimerization of two d-alanines. To obtain a better understanding of DdlA profiles and develop a colorimetric assay for hig...

Although of the many colorimetric microestimations of sugar the Folin and Wu method (1920) has remained in most widespread use in clinical laboratory practice, the still increasing number of modifications continue to draw attention to several inherent weaknesses of the method which have not yet been eliminated, one of which is the instability of the colour solution. To avoid these drawbacks a m...

Spectral printing aims to achieve an illuminant-invariant match between the original and the reproduction. Due to limited printer spectral gamuts, an errorless spectral reproduction is mostly impossible, and spectral gamut mapping is required to reduce perceptual errors. The recently proposed paramermismatch-based spectral gamut mapping (PMSGM) strategy minimizes such errors. However, due to it...

Banana is one of the most consumed fruits in Brazil and an important source of minerals, vitamins and carbohydrates for human diet. The characterization of banana superior genotypes allows identifying those with nutritional quality for cultivation and to integrate genetic improvement programs. However, identification and quantification of the provitamin carotenoids are hampered by the instrumen...

The development of rapid, specific, cost-effective, and robust tools in monitoring Hg(2+) levels in both environmental and biological samples is of utmost importance due to the severe mercury toxicity to humans. A number of techniques exist, but the colorimetric assay, which is reviewed herein, is shown to be a possible tool in monitoring the level of mercury. These assays allow transforming ta...