Patent ID: 11946917
Assignee: SHANXI KANGBAO BIOLOGICAL PRODUCT CO., LTD
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A detection method of polyethylene glycol monomethyl ether (mPEG-2000) residue in mPEG-b-PDLLA comprising steps of:
1) providing a high-performance liquid chromatography (HPLC) chromatographic device as follows:
setting an evaporative light scattering detector of the high-performance liquid chromatography (HPLC) device to operate at: a gain: 100-200, a drift tube temperature: 90-100° C., and a physicochemical gas pressure: 35-40.0 psi;
setting a liquid chromatography column of the high-performance liquid chromatography device, which includes a high-purity silica gel matrix as a filler in the column to operate at:

a flow rate: 0.8-1.0 ml/min;
a column temperature: 25-35° C.; and
an injection volume: 20 uL;
introducing a mobile phase A into the high-performance liquid chromatography column having: a volume ratio of 95:5 of 0.3 mmol/L ammonium acetate solution:acetonitrile, containing 0.2% acetic acid; and
then introducing a mobile phase B into the high-performance liquid chromatography column having: a volume ratio of 5:95 of 0.3 mmol/L ammonium acetate solution:acetonitrile, containing 0.2% acetic acid;
2) drawing a standard curve, which specifically comprises steps of:
dissolving a mPEG-2000 reference substance in the mobile phase A to prepare
mPEG-2000 standard solutions with different gradient concentrations between 25 μg/ml and 100 μg/ml, and detecting the mPEG-2000 concentration of the solutions with the detector of the chromatography device after filtration of the solutions in a filter having a pore size of 0.45 microns; during the detecting, introducing the mobile phase A and the mobile phase B as a gradient elution solution: from 0-10 minutes after a starting of elution, the elution solution comprising the mobile phase A being 85% of the elution solution, and the mobile phase B being 15% of the elution solution; from 11-30 minutes after the elution starting the mobile phase A being 65% of the elution solution, and the mobile phase B being 35% of the elution solution; from 31-40 minutes after the elution starting the elution solution comprising the mobile phase A being 50% of the elution solution, and the mobile phase B being 50% of the elution solution; and from 41-45 minutes after the elution starting, the elution solution comprising the mobile phase A being 85% of the elution solution, and the mobile phase B being 15% of the elution solution; and
using logarithmic values of chromatographic peak areas as ordinates and logarithmic values of concentrations of the mPEG-2000 standard solutions as abscissas, plotting test results of the high-performance liquid chromatography as standard curves and then fitting to obtain a standard curve equation:

Y=KX+b, 

wherein Y refers to the logarithmic values of the chromatographic peak areas, X refers to the logarithmic values of the mPEG -2000 concentrations, and K and b are constants;
3) preparing a test sample, which specifically comprises steps of: preparing the mPEG-b-PDLLA into a sample solution with a mPEG-b-PDLLA concentration of about 9.9-10.5 mg/mL and comprising the mobile phase A; and
4) detecting the mPEG-2000 residue in the sample solution with the detector of the chromatography device, which specifically comprises steps of: loading the sample solution in the column, and then loading the mPEG-2000 standard solutions in the column; comparing chromatograms of the sample solution and the standard solutions; identifying the mPEG-2000 in the sample solution by a difference of time where the mPEG-2000 is retained between the sample solution and the standard solutions; placing a logarithmic value of a chromatographic peak area of the mPEG-2000 in the test sample into the standard curve equation to calculate a concentration of the mPEG-2000 in the sample solution, and then calculating a residual amount of the mPEG-2000 in the sample solution.