Flow Scheme and Hyphenation

As narrow capillaries are undesirable because they contribute significantly to the back pressure, the resulting low flow rates would not allow fast sample transfer from the process unit under investigation to the NMR probe when a direct connection is used. U sing a split valve in front of the NMR probe, as described in the experimental section, the sample can be transferred in accelerated flow to the NMR probe, while the rest of the sample bypasses the probe at a reduced flow rate. 

NMR measurements. Cl laboratory reactor, FI inlet filter, VI (tee) purging valve, PI thermostated dosing pump, V2 back pressure regulator, V3 shut-off valve, V4 variable back pressure regulator for split adjustment, V5, V6 pressure relief valves, Pll, PIR2  

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