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Project Pelican Fluorescent tags Sept 2014

Project Pelican Fluorescent tags Sept 2014. Dr Helen Willcock. Tags. Absorbance ↓. <1000ppm detection is erratic. Absorbance ↑ Fluorescence. Fluorescent tags. Fluorescein. Anthracene. Rhodamine. λ Abs ~525 nm λ Em ~600 nm. Chem. Commun . , 2012,  48, 1117-1119.

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Project Pelican Fluorescent tags Sept 2014

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  1. Project Pelican Fluorescent tagsSept 2014 Dr Helen Willcock

  2. Tags Absorbance ↓ <1000ppm detection is erratic Absorbance ↑ Fluorescence

  3. Fluorescent tags Fluorescein Anthracene Rhodamine λ Abs ~525 nm λEm ~600 nm Chem. Commun., 2012, 48, 1117-1119. Fluorescent tags are more sensitive

  4. Copolymerisation Add GPC trace of HW379 • 0.3 wt% rhodamine, Mn 500kDa, 525nm absorbance detectable down to 10ppm SENT TO KAT

  5. Fluorescent Tagged Adsorption Test Initial attempt to ‘tag’ the polymer utilised Rhodamine due to its significant response in the UV/VIS region.

  6. Fluorescent Tagged Adsorption Test Whilst the rhodamine tag offered increased response and lower limits of detection, the rhodamine itself adsorbed to the sand matrix producing skewed results.

  7. Fluorescent Tagged Adsorption Test • Switched back to test brine after approx 32 days. • Initial rapid decrease in absorbance of effluent samples. • Elevated absorbancies due to detector drift.

  8. Fluorescent Tagged Adsorption Test • Depacked sand showed signs of pink discolouration due to free rhodamine adsorption. • Free rhodamine being eluted giving false data for polymer elution.

  9. Fluorescent Tagged Adsorption Test - Summary Free Rhodamine produced elevated absorbances resulting in suspect polymer elution profile. Long term drift in detector baseline resulting in elevated baseline absorbances.

  10. Extraction from sand Samples of sand pack extracted with trifluoroethanol (good solvent for both polymer and rhodamine)

  11. Extraction from sand • Dialysis confirms rhodamine is not attached to polymer • Stock solution contains no small molecule rhodamine Dialysate contains rhodamine after 1 hour Some rhodamine is cleaved under sand pack conditions No Cr found by ICP MS

  12. Properties/Explanation Adsorption onto hair, filter paper and photographic paper M. Long, D. W. Thornthwaite, S. H. Rogers, G. Bonzi, F. R Livens and S. P. RannardPolym. Chem., 2012, 3(1), 154 - 161 Fluorescent tags have been shown to bind to surfaces using radiolabelling

  13. DTM as fluorescent monomer New fluorescent probe developed within the group Chem. Sci., 2014,5, 2717-2723. J. Am. Chem. Soc., 2013, 135 (8), pp 2875–2878.

  14. DBM pro-fluorescent monomer C, D and E A A B Purified by column chromatography (80/20 pet ether/ethyl acetate).

  15. Copolymerisation Conditions - DMAPS:CPTA:ACVA= 1850:1:0.2 DMAPS/0.5 M NaCl ,1/10 w/v, 70 ºC. Purified by dialysis. Polym. Chem., 2014, 5, 1023-1030. DBM copolymerised at 0.3wt% (comparable to rhodamine polymer) and 3wt% DBM was substituted with thiol

  16. Fluorescent polymers 0.3 wt% Mn 500 kDa UV absorbance in GPC ↑ as mol % fluorescent monomer ↑ 3wt% Blue RI Red UV 420 nm

  17. Fluorescent polymers λ Abs ~420 nm λEm ~520 nm Not “bright” enough – hydrophilic environment affects intensity

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