Extracted pages from Theroretical instrumental Analysis Pharm D Clinical 2023-2024.pdf

Spectrophotometry: spectro- = spectrum photo- = light or photon - metry = measurement {measuring light spectrum} It is one of the instrumental methods of...

Spectrophotometry: spectro- = spectrum photo- = light or photon - metry = measurement {measuring light spectrum} It is one of the instrumental methods of analysis that depends on measuring the interaction between electromagnetic radiation (EMR) and molecules or atoms. It is used for structural and quantitative analysis of substances. Colorimetry (Visible Spectrophotometry): It is a branch of spectrophotometry in which the spectrophotometric measurement is performed in the visible region of light. Electromagnetic radiation (EMR): It is a form of energy that consists of 2 fields, electric field & magnetic field, and both are perpendicular to each other and perpendicular to the direction of the radiation propagation. Light is a type of electromagnetic radiations.  58  (OHFWURPDJQHWLF6SHFWUXP 7KH HOHFWURPDJQHWLFVSHFWUXP LVWKHGLVWULEXWLRQRI HOHFWURPDJQHWLF UDGLDWLRQ DFFRUGLQJWRHQHUJ\DQGZDYHOHQJWK 8OWUDYLROHWUHJLRQ§ – QP 9LVLEOHUHJLRQ§ – QP 5HPHPEHU  - QDQRPHWHU QP   P $QJVWURP c -P 3URSHUWLHVRIHOHFWURPDJQHWLFUDGLDWLRQ (05  1. :DYHOHQJWK Ȝ³/DPEGD´  WKHOLQHDUGLVWDQFHEHWZHHQVXFFHVVLYHPD[LPDRU PLQLPDRIDZDYH>8QLWVQPc««HWF@ 2. )UHTXHQF\ Ȟ³1X´  WKHQXPEHURIZDYHVSHUVHFRQGRUWKHQXPEHURIF\FOHV RU RVFLOODWLRQV SHU VHFRQG >8QLWV V- RU +HUW] +] @  +] PHDQV  F\FOH SHU VHFRQG  59 3.:DYHQXPEHU Nj ³1X EDU´   WKH QXPEHU RI ZDYHV SHU FHQWLPHWHU DQG LW LV HTXDOWRWKHUHFLSURFDORIZDYHOHQJWKH[SUHVVHGLQFHQWLPHWHU Ȝ >8QLWVFP-@ 4. 7KHYHORFLW\RIOLJKW IUHTXHQF\[ZDYHOHQJWK F ȞȜ  7KHYHORFLW\RIOLJKWLQYDFXXP F HTXDOV[ NPV 7KHIUHTXHQF\ Ȟ LVLQYHUVHO\SURSRUWLRQDOWRWKHZDYHOHQJWK Ȝ 5. 7KHHQHUJ\ ( RIDVLQJOHSKRWRQ (  KȞZKHUH³K´LV3ODQFN¶VFRQVWDQW  KFȜZKHUH³F´LVOLJKWYHORFLW\ (ĮȞDQG(ĮȜ 7KHKLJKHULVWKHZDYHOHQJWKWKHORZHULVWKHIUHTXHQF\ WKHORZHULVWKHHQHUJ\ ĹȜŁĻȞŁĻ( DQG ĻȜŁĹȞŁĹ( 89OLJKW LVPRUHHQHUJHWLFWKDQ YLVLEOHOLJKW DQGWKDQ ,5 6R89OLJKWLVPRUHGDQJHURXVWRWKHERG\WKDQYLVLEOHOLJKWDQG,5 ,QWHUDFWLRQRIOLJKWZLWKPDWWHU ,WLQFOXGHVWKHSURFHVVHVRI$EVRUSWLRQDQG(PLVVLRQ :KHQPROHFXOHVDUHVXEMHFWHGWROLJKWVRPHRIWKHPDEVRUEDSRUWLRQRIWKHOLJKWDQGDV DUHVXOWFHUWDLQHOHFWURQVZLWKLQWKHPROHFXOHVXQGHUJRDWUDQVLWLRQIURPWKHJURXQGVWDWH ORZHUHQHUJ\OHYHO WRH[FLWHGVWDWH KLJKHUHQHUJ\OHYHO Ÿ Ÿ^$EVRUSWLRQ`  60 7KHQ WKH HOHFWURQV UHWXUQ IURP WKH KLJKHU HQHUJ\ OHYHO WR WKH ORZHU HQHUJ\ OHYHO UHOD[DWLRQ DQGWKLVSURFHVVPD\EHDVVRFLDWHGZLWKHPLVVLRQRIOLJKWRIRQO\FHUWDLQ FKDUDFWHULVWLFZDYHOHQJWKVŸ Ÿ^(PLVVLRQ` Types of Transitions ¾ σ → σ* transition: Electrons in σ orbitals form single bonds, and thus to be excited to the į* they needs very high energy.ERQGEUHDNLQJ ,