Patent ID: 11860075
Assignee: ORGANO CORPORATION
Field: Measurement (Instruments)
Classification: CPC G  B  C | IPC B  C  G

Claim 7:
8. An analyzing apparatus for quantifying urea in a sample solution with a urea concentration up to 50 ppb, the analyzing apparatus comprising:
pretreatment means for pretreating a sample solution; and
an analyzer for quantifying urea in the pretreated sample solution directly after the pretreating,
wherein the pretreatment means comprises a membrane device including a reverse osmosis membrane,
wherein a rate of urea in the sample solution removed in the membrane device is obtained by the analyzer, and
wherein the analyzer is configured to correct a quantitative value of urea concentration detected during analysis based on the rate of urea removal,
wherein the analyzer is a flow injection analyzer for quantifying urea in the sample solution by a colorimetric method using diacetyl monoxime, and the analyzer comprises:
a reaction coil to which a carrier solution is continuously supplied;
a sampling valve for injecting a certain amount of the sample solution that has passed through the pretreatment means into the carrier solution supplied to the reaction coil;
a feeder for adding reagents to the carrier solution to which the sample solution has been injected at a position between the sampling valve and the reaction coil; and
a detector for measuring absorbance of liquid discharged from the reaction coil,
wherein urea and the reagents are reacted in the reaction coil,
wherein the reagents comprise a diacetyl monoxime-containing reagent solution and an antipyrine-containing reagent solution,
wherein the analyzing apparatus further comprises:
a reservoir for storing at least one of the reagents, and
a refrigerator for cooling the reservoir, and
wherein a temperature of the antipyrine-containing reagent solution is maintained at 5° C. or higher and 15° C. or lower after preparation of the antipyrine-containing reagent.