D iatomite is an inexpensive natural mineral. It can be used as an adsorbent to remove organic and inorganic pollutants from the waste waters without further improvement. In this research, the adsorption of two different basic colorants including Basic Yellow 28 (BY28) and Malachite Green (MG) by diatomite has been investigated in an aqua binary mixture and the effects of different parameters h...

Consumers are avoiding foods containing synthetic colourants, which lead food industries to replace them by natural pigments. Food colorants may be classified into synthetic, nature-identical, inorganic and natural colorants. Natural colorants for food are made from renewable sources. Most often, the colorants are extracted from plant material, but other sources such as insects, algae, cyanobac...

key words: 1064 nm dispersive Raman spectroscopy, pigment analysis, traditional red artists’ colorants Raman spectra of red colorants were obtained in-situ using a dispersive Raman microscope equipped with a 1064 nm laser source and InGaAs array detector. By employing nearIR excitation, the fluorescence of organic colorants is significantly reduced compared to visible wavelengths. Spectra prese...

A simple and rapid high-performance liquid chromatography (HPLC) method to determine basic colorants such as pararosaniline (PA), auramine O (AO), and rhodamine B (RB) in various processed foods was developed. Linearity of the calibration curves ranged from 0.05 to 50 μg/mL for PA and 0.05-100 μg/mL for AO and RB. The detection and quantification limits (LOD and LOQ) of the basic colorants, whi...

The identification of organic colorants in works of art has traditionally been one of the most difficult challenges in cultural heritage science. While non-invasive methods such as X-Ray fluorescence spectrometry (XRF), or Raman microscopy are extremely useful for the identification of inorganic pigments, they remain generally unsuitable for the analysis of most organic colorants. The absence o...

With the impact of globalization on research trends, the search for healthier life styles, the increasing public demand for natural, organic, and "clean labelled" products, as well as the growing global market for natural colorants in economically fast-growing countries all over the world, filamentous fungi started to be investigated as readily available sources of chemically diverse pigments a...

Non-destructive tests (NDT) of historical artifacts are the ideal scientific tools for the analyses of culturally important heritage objects. However, for the investigations of certain materials, especially natural organic dyes and pigments, it is important for curators, conservators, and scientists to be aware that such analyses are not always practical or prudent. At best, NDT can definitivel...

Today, synthetic organic pigments play a major role as colorants of excellent light-fastness in artists' paints. Their analytical determination in paintings gains steady importance with respect to attribution and studio practice of certain artists as well as dating and authentication. Synthetic organic pigments have extremely varied chemical structures and properties such as colouring strength,...

We present a novel spectral imaging technique that allows multiple gray-scale images to be combined in a single hardcopy print. The images are individually revealed when the print is illuminated by suitably chosen light sources. In its basic form, the technique utilizes the complementary relation between cyan, magenta, and yellow colorants and narrow band red, green, and blue illuminants to com...

Mazeyar Parvinzadeh Gashti , Farbod Alimohammadi, Guowen Song, Amir Kiumarsi 1 Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland 2 Young Researchers Club, Textile Department, Islamic Azad UniversitySouth Tehran Branch, Tehran, Iran 3 Department of Human Ecology, University of Alberta, Canada 4 Department of Organic Colorants, Institute for C...