Flow-injection analysis and variable-flow light-scattering methods and apparatus for characterizing polymers

A method for characterizing a non-biological polymer sample, the method comprising

• injecting a non-biological polymer sample into a mobile phase of a continuous-flow light-scattering detector,
• advancing the injected sample toward a detection cavity of the detector, the sample-containing mobile phase having an advancing flowrate, VADVANCE, while the injected sample is advanced toward the detection cavity,
• reducing the flowrate of the sample-containing mobile phase to a detection flowrate, VDETECT,
• detecting light scattered from the injected sample or from a component thereof in the detection cavity of the detector while the mobile-phase flowrate is reduced to the detection flowrate, VDETECT, and
• flushing the sample from the detection cavity after detecting the scattered light.

A method for characterizing a non-biological polymer sample, the method comprising

• injecting a non-biological polymer sample into a mobile-phase of a continuous-flow light-scattering detector,
• detecting light scattered from the injected sample or from a component thereof in a detection cavity of the detector, the sample-containing mobile phase having a detection flowrate, VDETECT, while the scattered light is detected,
• flushing the sample from the detection cavity after detecting the scattered light,
• increasing the flowrate of the sample-containing mobile phase to a passing flowrate, VPASS, after detecting the scattered light, and
• passing the flushed sample away from the detection cavity of the detector at the increased higher flowrate, VPASS.

A method for characterizing a plurality of non-biological polymer samples, the method comprising

• serially injecting a plurality of non-biological polymer samples into a mobile phase of a continuous-flow light-scattering detector,
• advancing the injected samples toward a detection cavity of the detector,
• detecting light scattered from the injected samples or from a component thereof in the detection cavity,
• flushing the samples from the detection cavity after detecting the scattered light,
• passing the flushed sample away from the detection cavity, and
• controlling the flow-rates of the samples during the steps of injecting, advancing, detecting, flushing or passing such that the average sample throughput is not more than about 60 seconds per sample.

A method for characterizing a plurality of non-biological polymer samples, the method comprising

• (a) withdrawing a non-biological polymer sample from a sample container,
• (b) injecting the polymer sample into a mobile-phase of a continuous-flow light-scattering detector while the mobile phase has an advancing flowrate, VADVANCE,
• (c) advancing the injected first sample toward a detection cavity of the detector while maintaining the flowrate of the mobile phase at the advancing flowrate, VADVANCE,
• (d) reducing the flowrate of the mobile-phase to a detection flowrate, VDETECT,
• (e) detecting light scattered from sample or from a component thereof in the detection cavity of the detector while the mobile-phase flowrate is at the reduced detection flowrate, VDETECT,
• (f) flushing the first sample from the detection cavity after detecting the scattered light,
• (g) increasing the flowrate of the mobile-phase to a passing flowrate, VPASS that is substantially the same as advancing flowrate, VADVANCE, after detecting the scattered light,
• (h) passing the flushed sample away from the detection cavity of the detector while maintaining the flowrate of the mobile phase at the passing flowrate, VPASS, and
• (i) repeating steps (a) through (h) for a plurality of non-biological polymer samples.