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26 chromatography • spectroscopy


A


B


Fig. 2. Construction of a dual-flow RI detector.


occurs using a dual-flow RI detector compared to that of a conventional RI detector.


Te reproducibility of the weight- average molar mass, Mw


Samples: , for the dual- flow detector was superior by a factor


of three than the reproducibility for the conventional RI detector.


In addition the day-to-day reproducibility and repeatability for the determination of Mw


varies


by less than 0.5 per cent for the dual-flow RI detector, while the conventional RI detector shows a variation of 1-3 per cent.


Polystyrene standards, molar mass from 266 to 7.06 × 105g/mol, Mw/Mn = 1.01 from Tosoh Bioscience; Dicyclohexylphthalate, 99 per cent pure; THF


Columns:


TSKgel SuperMultiporeHZ-M, 4µm, 4.6 mm ID × 15cm L × 2 + guard column TSKgel GMHXL-L, 6µm, 7.8mm ID × 30cmL + guard column


Solvent/mobile phase: THF; Flow rate: 0.35 and 1.0mL/min Temperature:


40°C (pump and column ovens and RI detector in the EcoSEC GPC System; column oven and RI detector in the modular system)


a


A stable RI detector baseline is required for successful experiments, in particular for repeatable and reproducible molar mass averages. Te repeatability and reproducibility of the molar mass averages have been shown to significantly increase by replacing a conventional RI detector with a dual-flow RI detector.


Te dual-flow RI detector shows unmatched baseline stability, excellent retention time reproducibility and day-to-


References: 1


2


day consistency compared to conventional RI detectors. Due to these features the dual-flow RI detector is an ideal tool for both single detector SEC and multi- detector SEC.


For more information ✔ at www.scientistlive.com/eurolab


Jens Reichenberger and Marina Urmann are with Tosoh Bioscience GmbH,


Stuttgart, Germany. Amandaa K Brewer is with Tosoh Bioscience LLC, King of Prussia, PA, USA. www.tosohbioscience.com


Striegel, A M; Yau, W W; Kirkland, J J ; Bly, D D Modern Size- Exclusion Liquid Chromatography, 2nd edition; Wiley: New York, 2009;


Goetz, H; Schulenberg-Schell, H Int J Polym Anal Charact, 2001, 6, 565;


3 Tchir, W J ; Rudin, A ; Fyfe, C A J Polym Sci, 1982, 20, 1443; 4 Ritter, A; Schmid, M; Affolter, S Polym Test, 2010, 29, 945; 5 Trathnigg, B; Jorde, Ch. J Liq Chromatogr, 1984, 9, 1789.


b


Fig 3 a and b. Comparison of baseline drifts of a dual-flow RI detector and two conventional RI detectors using semi-micro (a) and conventional (b) SEC columns. www.scientistlive.com


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