Qhov tseem ceeb ntawm kev tawm dag zog thiab nqus tau qhov kev ntsuas kho qhov muag tau siv ob qho tib si, qhov kev txiav txim siab ntawm qhov nqus ntawm lub teeb rau hauv kev txiav txim siab.
Ob qho tib si optical ceev thiab absorbance yog cov ntsiab lus cuam tshuam. Optical density (OD) yog qhov degree uas qhov nruab nrab refractive retards kis rays ntawm lub teeb thaum absorbance yog ib qho kev ntsuas ntawm lub peev xwm ntawm ib yam khoom los nqus lub teeb ntawm ib tug teev wavelength.
Dab tsi yog Optical Density?
Optical ntom ntom (OD) yog qib uas qhov nruab nrab refractive retards kis rays ntawm lub teeb. Hauv lwm lo lus, optical ntom ntom yog ib lo lus uas piav qhia txog kev nthuav tawm ntawm lub teeb nthwv dej los ntawm cov khoom. Kev ntsuas ntawm qhov muag pom qhov ntom ntom yog coj los ua qhov sib piv ntawm logarithmic ntawm qhov xwm txheej hluav taws xob ntawm cov khoom thiab cov hluav taws xob xa los ntawm cov khoom. Yog li ntawd, optical ceev cuam tshuam qhov ceev ntawm lub teeb los ntawm ib yam khoom. Lub ntsiab tseem ceeb cuam tshuam rau qhov pom kev ceev yog qhov wavelength ntawm lub teeb yoj.
Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias qhov ntom ntom ntawm qhov muag tsis muaj kev sib raug zoo nrog lub cev ntom ntom ntawm cov khoom. Optical density qhia qhov nyiam ntawm cov atoms lossis molecules ntawm cov khoom khaws cia lub zog nqus. Qhov kev tuav cia no tshwm sim los ntawm kev vibrations hauv hluav taws xob. Yog li ntawd, yog hais tias qhov optical ceev ntawm ib yam khoom yog siab, qhov ceev ntawm lub teeb los ntawm cov khoom no yog tsawg (vim lub teeb tsis txav maj mam). Tsis tas li ntawd, qhov pom kev ceev tuaj yeem ntsuas tau siv lub spectrometer.
Daim duab 1: Daim duab qhia pom qhov muag pom qhov ntom ntom ntawm Ribosome Sample
Lub refractive index ntawm ib yam khoom qhia qhov muag pom qhov ntom ntawm cov khoom ntawd. Yuav kom paub meej ntxiv, qhov sib piv ntawm qhov ceev ntawm lub teeb nyob rau hauv lub tshuab nqus tsev thiab qhov ceev ntawm lub teeb los ntawm cov khoom muab lub refractive index. Hauv lwm lo lus, qhov no piav qhia tias qeeb qeeb ntawm lub teeb hauv cov khoom sib piv rau qhov twg hauv lub tshuab nqus tsev.
Dab tsi yog Absorbance?
Absorbance yog ib qho kev ntsuas ntawm lub peev xwm ntawm ib yam khoom los nqus lub teeb ntawm ib lub wavelength. Tshwj xeeb, nws yog sib npaug rau lub logarithm ntawm lub reciprocal ntawm transmittance. Tsis zoo li optical ntom ntom, absorbance ntsuas qhov ntau ntawm lub teeb absorbed los ntawm ib yam khoom.
Tsis tas li ntawd, spectroscopy ntsuas qhov nqus (siv cov xim xim lossis spectrophotometer). Lub absorbance yog ib tug dimensionless khoom, tsis zoo li feem ntau lwm yam khoom ntawm lub cev. Muaj ob txoj hauv kev los piav txog kev nqus dej: raws li lub teeb nqus los ntawm cov qauv lossis raws li lub teeb kis los ntawm cov qauv. Qhov sib npaug rau kev suav ntawm absorbance yog raws li nram no:
A=log10(I0/I)
Daim duab 2: Teebmeem Radiation thiab kis hluav taws xob
Thaum A yog nqus, I0 yog cov hluav taws xob xa tawm los ntawm tus qauv, thiab kuv yog qhov xwm txheej hluav taws xob. Qhov kev sib npaug hauv qab no kuj zoo ib yam li cov kab zauv saum toj no, hais txog kev xa tawm (T).
A=-log10T
Dab tsi zoo sib xws ntawm Optical Density thiab Absorbance?
Ob qho tib si optical ceev thiab nqus tau ntsuas lub peev xwm ntawm tus qauv kom khaws cov hluav taws xob hluav taws xob hla dhau ntawm tus qauv
Qhov txawv ntawm Optical Density thiab Absorbance yog dab tsi?
Optical Density vs Absorbance |
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| Optical ntom yog qib uas qhov nruab nrab refractive retards kis rays ntawm lub teeb. | Absorbance yog ib qho kev ntsuas ntawm lub peev xwm ntawm ib yam khoom los nqus lub teeb ntawm lub wavelength. |
| ntsuas | |
| Kev ntsuas qhov muag pom kev siv ob qho tib si, kev nqus thiab tawg ntawm lub teeb, rau hauv kev txiav txim siab. | Kev ntsuas qhov nqus tau tsuas yog siv qhov nqus ntawm lub teeb rau hauv kev xav. |
Summary – Optical Density vs Absorbance
Ob qho tib si optical ntom thiab nqus tau yog cov ntsiab lus cuam tshuam hauv kev tshuaj ntsuam chemistry. Lub ntsiab lus sib txawv ntawm qhov muag ceev thiab nqus tau yog qhov kho qhov muag pom kev nqus thiab ntsuas qhov kev sib haum xeeb tsuas yog nqus ntawm lub teeb.
