Title

Analysis of Fibre Dyes by High Performance Liquid Chromatography

Objective

To determine the fiber dyes in Pink, Brown and Red textile Sample

Introduction

High performance liquid chromatography (HPLC) systems are available for the analysis of basic, acid and disperse dyes. HPLC systems have been developed in this laboratory for the analysis of the dyes extracted from fibres. Casework size fibres can be analysed by HPLC and batch type differences have been detected. The addition of an autoinjector to the HPLC system is required to cope with the number of fibres which are to be analysed in a typical case. The extraction of dyes from fibres is usually carried out in capillary tubes, as for thin layer chromatography (TLC). The fibre is placed in a capillary tube, covered with extracting solvent, and the tube sealed and heated. The extract is removed using a gas chromatography (gc) syringe, and diluted with the HPLC eluent for injection onto the HPLC column. The extraction process is time consuming and some of the extract can be lost with resultant reduction in peak size.

Dyes have been used to alter the appearance of cloth and fabric by changing their colour since ancient times.(Garfield, 2000) Dyes can be defined as any substance which has an affinity for a substrate and, on binding to that substrate, alters the way in which the material absorbs light, and hence changes the colour that is subsequently observed. Colour is due to the preferential absorption of certain wavelengths of light, the observed colour being those wavelengths of light that are reflected. The particular bands of light absorbed, and hence the colour observed, by a particular dyed fabric is due to the chemical structure of the dye. For this experiments, we used Alizarin, Carminic Acid and Martious Yellow dyes.

Reagents and solutions

1. Methanol (HPLC Grade)2. Hydrochloric Acid (37%)3. Phosphoric Acid (5%)4. References dyes solutions (100 ppm) : Alizarin, Carminic Acid, Martious Yellow.

Apparatus

1. Small beakers2. Hot plate3. Dessicator4. Centrifuge5. Sample tubes

Sample

3 coloures textile pieces.

Instruments

High Performance Liquid Chromatography (Agilent G1314A) equipped with photoiodide array detector, 20 µL sample loop and 5µm RP C18 column.

Analytical Procedure

1. Sample Extraction

a) About 4 mg of textile fibre in 1.5 mL of H2O : methanol : 37 % HCI (1:1:2 v/v/v) was treated for 10 min at 100 oC in a small beaker.

b) The extract was cooled down and filtered by centrifuginal forces.c) The filtrate was dried in desiccator over NaOH and in vacuum.d) The residue was redissolved in an appropriate volume of methanol/water (1/1, v/v).

2. Instrument Set-up

Wavelength : 200 to 320 nm Mobile phase : (A) water, (B) methanol, (C) 5 % (w/v) phosphoric acid in water. Elution program : 66A:24B:10C for 2 mins, linear gradient to 0A:90B:10C for 27 minbs, and

hold on 0A:90B:10C for 3 mins. Flow rate : 1.2 mL/min

3. Dye Analysis.

100 µL of the sample extract was transfered into a clean, dried sample tube and 1 mL of the mobile phase was added and well shaked. 10 µL of the diluted sample was injected.

4. Identification of dye components in fabric extracts.

10 µL of each references solutions individually injected to identify the main dye components in the fabric extract.

Results

Standard Retention Time (min) AreaMartious Yellow 5.760 4473762

Alizarin 5.312 5612695Carminic Acid 2.805 2669832

Table 1 : Retention Time of Standard Injected

Sample Retention Time (min) AreaPink 5.365 14251580

Brown 2.325 12459044Red 5.845 38415

Table 2 : Retention Time for Sample Injected

Discussion

In this experiment, we used high performance liquid chromatography to analyze the extraction of textile fibers using photoiodide array detector to monitor the absorbance at several wavelength. Based on the results that we obtained, for pink textile sample, it contained Alizarin dyes because of the peak detected at retention time for the pink (5.365 min) sample was closest to the retention time only for the alizarin dyes (5.312 min) when we comparing both species. For Brown textile sample, it contained Carminic Acid dyes because the closest of peak detected at retention time for the brown sample (2.325 min) to the Carminic Acid dyes (2.805 min). For the third sample, Red textile sample shows that it contained Martious Yellow dyes due to the the closest peak detected at retention time for the brown sample (5.845 min) to the Martious Yellow Dyes (5.760 min). From the chromatograms that obtained, we found that, there are band broadening at the peaks of martious yellow and pink textile sample. The band was broaded due to the B/v effects. B/v effects causes the diffusion is 100 x less in liquids than in the gas and can be neglected. Another factor that contribute to the band broadening is Cv effects. For Cv effects, we assumed that mass transport effects are the largest contribution. The mobile phase mass transfer coefficient: CMv = (fM(k’)dp

2/DM)v. Smaller dp (particle diameter of packing) increases the surface area/volume ratio and thus decreases mass transport in the mobile phases.

Conclusion

We can coclude that the Pink textile sample contained Alizarin dyes, Brown textile sample contained Carminic Acid dyes and the Red textile sample contained Martious Yellow dyes.

References

RME GRIFFIN and SJ SPEERS (1995). Use of tapered vials for in situ extraction of fibre dyes for

analysis by HPLC. Northern Ireland Forensic Science Laboratory, 151 Belfast Road, Carrickfergus,

Northern Ireland, BT38 8PL. Retrieved November 13, 2012, from

http://www.sciencedirect.com.ezaccess.library.uitm.edu.my/science/article/pii/S1355030695726624

http://espace.library.curtin.edu.au/webclient/StreamGate?folder_id=0&dvs=1352791451625~57

Experiment 9:

Analysis of Fibre Dyes By High Performance Liquid CHromatography

Name : Nur Zuraihan Binti Abd Wahab (2011856974)

Normahani Binti Ramli (2011603842)

Group : ASB3Ag

Name of Lecturer : Miss Anis Shuhada