流动注射扩散法测定血氨

Flowinjectionanalysisofammoniainplasma

目的探索测定血氨的新方法。方法采用流动注射气体扩散技术，建立测定血氨的方法，对实验条件如流速、反应管长、样本体积、指示剂浓度进行了选择。测定了对照组５３例，胆囊结石组９例，门脉高压肝硬化组２６例，肝硬化并发肝性脑病组１０例的血氨含量。结果该方法线性范围０～４２８．４μｍｏｌ／Ｌ，变异系数（ＣＶ）为１．６％～２．０％，回收率为９８．７％～１０２．４％。测定了对照组（献血员）５３例（ｘ＝８１．２μｍｏｌ／Ｌ），胆囊结石组９例（ｘ＝８１．４μｍｏｌ／Ｌ），门脉高压肝硬化组２６例（ｘ＝１００．０μｍｏｌ／Ｌ），肝硬化并发肝性脑病组１０例（ｘ＝３０６．３μｍｏｌ／Ｌ）的血氨含量。可以看出，肝性脑病组明显高于对照组，胆结石组血氨值都在对照组均值范围内。结论流动注射扩散法测定血氨，简便、易行、精密度和准确度较好，试剂价廉易得，值得推广应用。

ObjectiveTodevelopthemethodofflowinjectionanalysisformeasuringammoniainplasma.MethodsTheprinciplesofmethodreliedontheabsorbancechangeofindicatorcausedbyammonia.Variousreactionconditions,suchasflowrate,lengthofreactiontube,samplevolume,concentrationofindicator(phenolred),etc,wereinvestigated.Samplesfrom26patientswithcir-rhosis,10patientswithhepaticcoma,9patientswithcholelithiasisand53controlsubjectswerestudied.ResultsGoodlinearitywasobservedbetween0～428.4μmol/L.Theintra-runandinter-runimprecisions(CV)were1.6%to2.0%.Therecoveriesrangedfrom98.7%to102.4%.Themeanconcentrationsinpatientswithcirrhosis(x=100.0μmol/L)andhepaticcoma(x=306.3μmol/L)weresignificantlyhigherthanthatinnormalsubjects(x=81.2μmol/L,P<0.01).Themeanconcentrationinpatientswithcholelithiasis(x=81.4μmol/L)wasnotsignificantlydiferentfromthatincontrolsubjects.ConclusionsThemethoddescribedhereformeasuringammoniawasrapid,sensitive,reproducibleandsuitedtothedevelopingcountriesasitscostwasverylow.Thewholeprocesswasinaclosedreactionsystem,avoidingtheinterferenceofexternalammonia.Thisstudyshowedthatmeasurementofplasmaammoniahadimportantsignificanceinprognosisanddiagnosisofhepaticcomaandcirrhosis.