Ch23. Introduction to Analytical Separations

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1 Ch3. Inoducion o Analyical Sepaaions 3. Medical Issue : Measuing Silicones Leaking fo Beas Iplans High olecula ass poly(diehylsiloane), PDMS, [(CH 3 ) SiO] n : Used as GC saionay phase, gels in beas iplans : ~% of silicones in beas iplans ae low-olecula-ass when leaks, i avel hough ciculaoy and lyph syse o deposi in lipid ich issues Ch3. Inoducion o Analyical Sepaaions 3.

2 3-. Solven Eacion 3.3 Eacion : ansfe of solue fo one phase o he ohe phase Why o use eacion? : o isolae o concenae desied analye. - Oganic solven dense han wae : CCl 4, CH Cl, CHCl 3 - Oganic solven lighe han wae : diehylehe, oluene Equilibiu in Solue Solue: S in phase Paiion coefficien: K A A S S [S] [S] A S i aciiviy Phase : volue V ( wae) Phase : V ( solven, oluene) 3-. Solven Eacion 3.4 If, : oal # of oles q : facion of S eaining in phase olaiy in phase K [S] [S] ( q) / V q / V Facion eaining in phase afe eacion q V V + KV q V Paiion coeff. If oluene eoved, and add fesh oluene fo coplee eacion, V Facion eaining in phase q q V + KV Repeaing esuls in he decease of facion eaining in wae.

3-. Solven Eacion 3.5. ph effec : if a solue is acidic o basic, solubiliy depends on ph (neual ol dissolves in oganic, chaged species in aqueous) ph is ipoan in eacion i.e.) Suppose conjugae acid: BH + is soluble only in aqueous phase.

3 3-. Solven Eacion 3.5. ph effec : if a solue is acidic o basic, solubiliy depends on ph (neual ol dissolves in oganic, chaged species in aqueous) ph is ipoan in eacion i.e.) Suppose conjugae acid: BH + is soluble only in aqueous phase. oal conc.in phase Disibuion coefficien : D oal conc.in phase + [B] [B] [B][H ] D + K K [B] a + D [B] + [BH K K ] a + Ka + [H K α ] B [BH α B : facion of he weak base in neual fo in aq. To eac base in wae, use HIGH ph o conve BH + B acid LOW ph ] 3- Wha is Choaogaphy? 3.6 Choaogaphy : siila o eacion One phase : fied saionay phase : solid (liquid coaed) paicles packed The ohe phase : oving obile phase : solven filled, liq o gas eluan eluae

siila o Liq-Liq eacion S.P.: S.P.: solid (silica, aluina,ec) GC- Liq s.

: Liq o Gas of inne wall of capillay songe solue adsopion LC- Liq s.

: Liq o Gas 3- Wha is Choaogaphy? 3.8 ion-echange: siila o Liq-Liq eacion S.

4 3- Wha is Choaogaphy? 3.7. Types of Choaogaphy Adsopion : adsopion on solid suface paiion : siila o Liq-Liq eacion S.P.: S.P.: solid (silica, aluina,ec) GC- Liq s.ph. bonded o SiO M.P.: Liq o Gas of inne wall of capillay songe solue adsopion LC- Liq s.ph. bonded o solid suface slow avel M.P.: Liq o Gas 3- Wha is Choaogaphy? 3.8 ion-echange: siila o Liq-Liq eacion S.P.: ionic goup aached on solid suface -SO 3- : aac caion Molecula eclusion: gel filaion o gel peeaion - sepaaion by size. -NH 4+ o N(CH 3 ) 3+ aac anion - Lage passes fase M.P.: Liq

3- Wha is Choaogaphy? 3.9 Affiniy choaogaphy : anibody iobilized on S. phase. only specific poeins apped o anibody 3-3. A plube s Poin of View 3.0 fo e) colun: id0.60c (0.30c) M.P. occupies 0% in volue colun vol of each c π(0.

5 3- Wha is Choaogaphy? 3.9 Affiniy choaogaphy : anibody iobilized on S. phase. only specific poeins apped o anibody 3-3. A plube s Poin of View 3.0 fo e) colun: id0.60c (0.30c) M.P. occupies 0% in volue colun vol of each c π(0.30) c 0.83 L - Volueic flow ae 0.30 L/in L / L/c 5.3 c 5.3c/in : linea flow ae. The choaoga: gaph showing he deeco esponse as ie

6 3-3. A plube s Poin of View 3. eenion volue ( ) : ie o each deeco fo injeco eenion volue (V ) : volue of M.P. o elue solue fo he colun dead ie ( ) : passage ie fo obiled phase hough colun adjused eenion ie ( ): elaive eenion (α) ' α ' fo eo coponens,, >, α> Fo each peak, capaciy faco (k ) k' (o eenion faco, cap. faco) o paiion aio k ' ie of solue in S.P. ie of solue in M.P A plube s Poin of View 3. ie of solue in S.P. oles of solue in S.P. k ' ie of solue in M.P. oles of solue in M.P. C C S V V [saple] [saple] S k ' K S ' K paiion coefficien α ' ' k ' k ' C C S V V s See eaple in P50 eenion volue (V ) V U v U v : volueic flow ae

3-3. A plube s Poin of View 3.3. Scaling Up choaogaphy fo analyical pupose : ge infoaion pepaaive use : collec facions Needs scale up - Ipoan in phaaceuical indusy - dug puificaion i.e.) g ou of.

7 3-3. A plube s Poin of View 3.3. Scaling Up choaogaphy fo analyical pupose : ge infoaion pepaaive use : collec facions Needs scale up - Ipoan in phaaceuical indusy - dug puificaion i.e.) g ou of.0-c diaee colun How lage i.d. colun needed fo sepaaing 0 g? 0g g adius.58c -- ~3c in diaee 0.50c Fo flow ae, us be he sae linea flow ae abou 0 ies aea incease 0 ies highe volueic flow ae 3-4. Efficiency of Sepaaion 3.4 How well sepaaed? by wha diffeences o say i bee o poo? - ie diffeence (fa apa) - boadness : wide peak pooe sepaaion, infoaion loss Solue peak -- boadened as gaussian (due o diffusion) The longe sepaaion, he boade he peak is

3-4. Efficiency of Sepaaion 3.5. Resoluion : easue of sepaaion beween wo peaks R s Δ w av ΔV w av 0.589Δ w / av Fo quaniaive Analysis R s >.5 3-4. Efficiency of Sepaaion 3.6.

8 3-4. Efficiency of Sepaaion 3.5. Resoluion : easue of sepaaion beween wo peaks R s Δ w av ΔV w av 0.589Δ w / av Fo quaniaive Analysis R s > Efficiency of Sepaaion 3.6. Diffusion Why becoes gaussian? Due o diffusion In a colun, # of oles cossing /uni aea/uni ie : flu : J ol Flu( ) J D s dc d D: diffusion coeff. (Table 3-) dc/d: conc. Gadien acoss a plane - sign: ne flu is fo high conc. o low conc.

9 3-4. Efficiency of Sepaaion Efficiency of Sepaaion 3.8 If a solue avels in a colun wih an infiniely shap dela funcion concenaion pofile: solve ou fo flu equaion C ep( ) 4πD 4D sd. dev : σ D C: ol/ 3, : disance along colun

10 3-4. Efficiency of Sepaaion Plae heigh : a easue of colun efficiency σ D D /u u D H u H σ Plae heigh Heigh equivalen o heoeical plae anohe eaning: lengh of colun equied fo one eq. of solue be. SP & MP By deceasing H bee sepaaion GC:~ 0.~, HPLC: ~0 μ C.E.: < μ fo a solue eeging fo colun L L L L 6L N H σ σ w Nube of plaes N σ 5.55 w / 3-4. Efficiency of Sepaaion Facos Affecing Resoluion R N ( γ ) 4 γ sepaaion faco( s B A ) Doubling N ies incease in Rs

11 3-5. Why Band Speads? 3. So any facos influence band boadening. They e addiive σ obs σ + σ + σ 3 + σ i. Boadening ouside he colun When saple enes colun, hey ae aleady in finie widh hough ubing. Δ (in unis of ie), σ inj σde ) ( Δ To iniize, educe he dead space, ubing lengh ec 3-5. Why Band Speads? 3.. Plae Heigh equaion Van Deee Eq. B H A + + Cu u A: uliple pah e o eddy diffusion B: longiudinal diffusion C: ass ansfe Flow ae is ciical Changing colun, sp vaies packed colun: A, B, C 0 OTC: A 0 CE: AC0

coeff. of solue in MP 3-5. Why Band Speads? 3.4 4.

12 3-5. Why Band Speads? Longiudinal Diffusion Along he ais of colun Raise u σ H inceased D D u plae heigh due o L.D. H D σ L D u B u D : diff. coeff. of solue in MP 3-5. Why Band Speads? Finie Equilibaion ie beween Phases : MASS TRANSFER Cu : finie ie fo solue o each Eq. plae heigh due o finie ie H Cu (C + C MT C s k' 3(k' + ) s d D s ) u C + 6k' + k' 4(k' + ) D : colun adius d: hickness of SP

13 3-5. Why Band Speads? 3.5 ass ansfe e can be deceased by T incease of T incease of D s To incease T, SP us be sable silica bases? Unsable ZO 3-5. Why Band Speads? Muliple flow pah : Eddy diffusion, A e igh packing egula shape, spheical bee unifo size: salle he bee

14 3-5. Why Band Speads? Advanage of Open Tubula Colun (OTC) In GC, OTC is used pefeenially - highe esoluion - shoe analysis ie - inceased sensiiviy - low saple capaciy OTC can be longe 00 ies han he packed a sae pessue - if H is he sae, N 0 ies Rs - no band boadening by uliple pahs - A e occupies ~half of H, upo ~30Ml/MIN. IF A is deleed, N is doubled - Needs o be sall adius 3-5. Why Band Speads? 3.8

15 3-5. Why Band Speads? A Touch of Realiy: Asyeic band shapes ideal gaussian coes when K(C s /C ) is independen of concenaion bu in eal colun, K changes as C s, C incease band skewed i) Too uch solue loaded? oveloaded ii) When sall quan. of solue eained oe songly han lage quaniy ailing 3-5. Why Band Speads? 3.30 When silica sufaces (silanol) binds H-bond wih pola solue seious ailing Silanizaion: blocking uneaced hydoy goup wih TMS (iehylsilyl goup)

Separation. Ch. 23 Fundamentals of Analytical Separations. Extraction Efficiency

Separation. Ch. 23 Fundamentals of Analytical Separations. Extraction Efficiency Sepaaion Ch. 3 Fundaenals of Analyical Sepaaions Saples ae usually coplex ixues. In ode o idenify and quanify he coponens of a ixue, we have o sepaae he coponens in he ixue. Sepaaion ehods Exacion Choaogaphy