HPLC Determination of Four Textile Dyes and Studying their Degradation Using Spectrophotometric Technique

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Type: 
Thesis
Year: 
2005
Students: 
Safwat Mohammad Abdul Azeez Saleh
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HPLC Determination of Four Textile Dyes and Studying their Degradation Using Spectrophotometric Technique1.05 MB
Abstract: 

In the present work, a simple and a sensitive HPLC method was developed for quantitative determination of four Direct textile dyes (Direct Red 81, Direct Blue 15, Direct Black 22 and Direct Orange 34). The maximum absorbance value for the above mentioned dyes were found to be at 510 nm, 607 nm, 484 nm and 411 nm, with retention times of 15.4, 8.8, 5.8 and 12.7 min, respectively. The mobile phase used was consisting of acetonitrile: water (60:40, v/v) containing 0.45 M N-cetyl-N,N,N-trimehyl ammonium bromide (CTAB). RP C18 column was used with a flow rate of 0.5ml/min. Calibration graphs were found to be linear over the ranges of 0.3–10ppm, 10–30ppm, 0.5–10ppm and 1–12ppm for Direct Red 81, Direct Blue 15, Direct Black 22 and Direct Orange 34, respectively, with limit of detection 0.3ppm, 10ppm, 0.5ppm and 1ppm. The relative standard deviations (RSD%) were found to be 0.92 %, 0.83 %, 1.13 % and 0.34 %, respectively (n=3) with concentrations of 10ppm of each dye. The effect of pH, CTAB concentration and acetonitrile: water ratios (v/v) in the mobile phase on the determination of the four Direct azo dyes were investigated. The reducing degradation kinetics of the four Direct dyes; Direct Red 81, Direct Blue 15, Direct Black 22 and Direct Orange 34 by zero– valent iron and aluminum metals in aqueous solutions were studied. Effective degradation was achieved when using Al compared to Fe. The results show that the rate of degradation is affected by acidity, amount of iron and aluminum, temperature and speed of solution agitation. The effect of metals nature on degradation of the four Direct azo dyes was studied. The following metals were used in this study (Mn, Ni, Co, Zn, Mg and Cu). The obtained results showed that using Cu do not effects on degradation rate, where using Al, Mg give a higher degradation rate compared to iron.