Identification Of Synthetic Dyes Research Articles

Research on Grape and Fruit and Berry Wines and Detection of their Falsification

Grape and fruit and berry wines were studied in order to detect signs of their falsification by adding synthetic dyes.
 It is noted that in the process of analysis (examination) of unknown liquids provided for research, specialists must first of all establish the nature of such objects. It is possible to find out only after identifying the spectrum of features characteristic of the object in its actual state. The list of organic acids, which are components of grape and fruit and berry wines, was established experimentally; the possibility of determining organic acids in the analyzed samples was proven; signs of falsification of wines with the addition of dyes were given and methods of their detection were proposed. One of the cornerstone requirements for forensic examination is the mandatory confirmation of the results of analysis by at least two reliable methods, therefore, in the proposed scientific research, options for the study of some synthetic dyes using methods of thin- layer chromatography, IR spectroscopy and the addition of alkaline solutions are considered. It was established that the set of specific organic acids in grape and fruit and berry wines, which can be detected using the chromatography method, makes it possible to use them as differential signs in the process of establishing the nature of the wine. Samples of real grape wines are marked by a high concentration of tartaric acid, which is present only in grape products. It has been proven that the set of methods for studying grape and fruit and berry wines, aimed at determining the presence and identification of synthetic dyes, makes it possible to answer the questions posed by the examination on the falsification of winemaking products by coloring.

Application of quadrupole-Orbitrap high-resolution mass spectrometry in rapid screening and identification of synthetic dyes in herbal medicines

In this work, a method combining ultra-high performance liquid chromatography and hybrid quadrupole-Orbitrap high-resolution mass spectrometry (HR-MS) was developed and validated for use in the simultaneous screening, identification, and quantification of 21 synthetic dyes in herbal medicines. To optimize the chromatographic conditions, we used a combined Full mass scan and data-dependent MS/MS (Full MS/dd-MS2) approach in positive and negative ion mode. Under this mode, selected ions with given fragmentation energy were subjected to a dd-MS2 scan following a Full MS scan. The selectivity of this method was effectively improved using 70,000 full width at half maximum mass resolution and narrow mass window (typically 5 ppm), and a single injection was sufficient for simultaneous identification and quantification of 21 synthetic dyes within 10 min. The combined method was fully validated and complies with all criteria for selectivity, sensitivity, calibration curve linearity, accuracy, precision, recovery, matrix effect, and stability. All analytes showed excellent linear relationships as all the coefficients of determination (r2) are greater than 0.9978 over wide ranges of concentrations (e.g. 1.0-500 ng/mL for sunset yellow). The validated method was employed to detect synthetic dyes in herbal medicines and was demonstrated to provide a reliable technical basis for drug regulation and public health protection.

Identification of synthetic dyes in early colour photographs using capillary electrophoresis and electrospray ionisation–mass spectrometry

Capillary electrophoresis with photodiode array detection (CE-PDA) and with electrospray ionisation-mass spectrometry (CE-ESI-MS) was used for the separation and the identification of 23 synthetic organic dyes, among those used in early 20th century colour photographs such as autochromes. Both cationic and anionic dyes could be separated within 15min using a single CE-PDA method. The method was used as the basis to develop a CE-ESI-MS methodology through the optimisation of the relevant ESI and MS parameters. Sheath liquid composition, nebulising gas pressure, drying gas flow rate and drying gas temperature were found to influence the sensitivity of the detection. These parameters were optimised in positive and negative ion modes for cationic dyes and anionic dyes, respectively. The two analyses could be carried out successively on a single sample. In view of the application to cultural heritage objects, the CE-ESI-MS analytical procedure was applied to identify the dyes in a Filmcolor artefact, late version of the autochrome. The results complemented and enhanced current knowledge as four cationic dyes and three anionic dyes were identified. Four additional dyes are proposed as possibly present as traces.

Modern methods for identification of synthetic dyes used in counterfeit wines.

This paper presents partial results obtained in Sectoral Plan Project 314/2006, funded by Agricultural Ministry- MARD. The quantitative method HPLC (High Perfomance Liqhid Chromatography), is powerful and fast. Because of its resolution, sensitivity and accuracy, in recent years has become the preferred method for quantitative analysis of synthetic dyes in wines. For testing the efficiency of this method used in identifying artificial dyes were used contaminated tipical wine samples from the research zones with the most known artificial colorings used in couterfeit wine. At ICSI Rm Vâlcea HPLC method was adapted for simultaneous determination of five synthetic food dyes: Azorubin, Amaranth, Ponceau 4R, Red Allure AC, Erythrosin, which can be used to detect synthetic additives in red wines in order to correct color deficiencies and to achieve red wines from white wines. The figure below is reproduced chromatogram from a sample of Italian Riesling from SCDVV Murfatlar contaminated with dye red-allure AC.

Extraction of organic acids by ion-pair extraction with tri- n-octylamine — VIII. Identification of synthetic dyes in pharmaceutical preparations

Synthetic dyes were extracted from syrups, oral suspensions, tablets, gelatin capsules, suppositories and granules by ion-pair formation with tri- n-octylamine (TnOA) and back-extracted with perchlorate ions. Identification was performed by TLC on cellulose layers and by reversed phase ion-pair HPLC.