persepsi memori dan lupa e
Anabolicm inds Archive
BEGI N N ERS GU I D E T O SO X H LET EX T RACT I O N S
CH EM O
Adm inist r at or
Subm it t ed: Apr il, 2003
SUM M ARY
The ext ract ion m et hods present for m ost solid sam ples usually involve a subst ant ial am ount of w et
chem ist ry . I f one w er e not v er sed in t he chem ical ar t s it is har d t o be confident and pr oact iv e in
heading off exper im ent failur e due t o lack of educat ion, ex per ience, or under st anding. A viable
alt er nat iv e t o t he t r adit ional w et m et hods of solv ent ex t r act ion is a Sox hlet t y pe of apparat us w hich
allows for near 100% act iv e m ateria l recovery and user fr iendliness. Th e gen er al
I n t his m ini- ar t icle w e w ill explor e efficient solid- liquid ex t r act ions using a Sox hlet t y pe apparat us
and applicat ion of t heor y t o ut ilit y set ups.
GEN ERAL BACKGROU N D
The sim plest form of solid- liquid ex t r act ion is t he t r eat m ent of a solid wit h a solvent . An exam ple
of t his w ould be in separat ing a sand/ salt m ixt ure by using w at er. Sw ir l for a few m om ent s and
decant , or pour off, t he salt ( now in t he w at er layer) . The sand r em ains since it is I N SOLU BLE.
I n all solv ent ex t r act ions an at t em pt is m ade t o t ak e adv ant age of differ ences in solubilit y bet w een
t he species being separ at ed.
1. Soxhlet
Th e apparat us, first described in 1879, is a v er sat ile t ool
t hat can be used t o separ at e a single gr am t o hundr eds of
gr am s w it h near 100% r ecov er y .
FI GURE 1 . 1 – Ty pical Set up
The basic pr ocedur e calls for a solid sam ple t o be placed in
a por ous cont ainer and allow ing condensed solv ent t o
ex t r act cont inuously. The figur e on t he r ight show s t h e
basic com pone nt s of a Sox hlet apparat us:
•
•
•
PAGE 1 of 4
Con de n se r
Funct ion is t o cool t he solv ent v apor and cause it t o
c ondense ( t urn back int o a liquid) . Figur e 1.1
show s a r ing t y pe of condenser w hich funct ions by
incr easing t he sur face ar ea t hat can be used t o
t r ansfer heat . This is very sim ilar t o a h eat
ex ch an ger or aut om ot iv e r adiat or t hat is used t o
du m p ex cess h eat .
Po r o u s Co n t a in e r
Funct ion is t o hold t he solid sam ple and allow for
t he condensed solv ent t o sat ur at e and pass t hr ough
t her eby ex t r act ing act iv e m at er ial. This can be
likened t o a filt er in t hat it r et ains t he insoluble
com ponent s and allow s w hat ev er is dissolv ed t o
pass.
D ist illin g Pot
Funct ion is t o hold t he solv ent pool and ser ve as a
r eser v oir for t he concent r at ed m at er ial.
AN ABO LI CM I N D S. CO M
BEGI N N ER | I n t er m ediat e | Adv anced
Anabolicm inds Archive
BEGI N N ERS GU I D E T O SO X H LET EX T RACT I O N S
2. Basic Operat ion
The solv ent v apor , gener at ed by gent ly
heat ing t he r eser v oir, condenses and is
allow ed t o dr ip back ont o t he porous sam ple
cup.
FI GURE 1. 2 – Ut ilit y Set up
The liquid condensat e t hat dr ips ont o t he
sam ple per for m s t he ex t r act ion w hich t hen
passes t hr ough t he cont ainer and back int o
t he r eser v oir . The cy cle is r epeat ed
cont inuously and can be sust ained as long
as needed. As it progresses t he species of
int er est is concent r at ed in t he r eser v oir .
I n a r ev er se ex t r act ion t he species being
elim inat ed m ay be concent r at ed in t he
reserv oir inst ead. An exam ple of t his m ay
be t o use w at er as t h e solv ent w it h a
m et hylc ellulose based m at r ix t o be
ex t r act ed. I n t his scenario t he
m et hy lcellulose w ould be collect ed in t he
reservoir and t he act iv e species r et ained in
t he porous sam ple cup. As elim inat ion of
solvent m ay be a concer n for som e t his
met hod only uses w at er t o per for m t he
ext ra ct ion and is easily pushed off dur ing
com m on dr y ing pr ocedur es.
Rat e of r eflux is especially im por t ant her e as
low v apor pr essur e solv ent s such as acet one
or m et hanol m ay condense fast er t han t he
pass- t hr ough r at e. This w ill c ause t he level
of solvent in t he porous sam p le cup t o
accum ulat e and ev ent ually spill over t he
side possibly t aking m at er ial w it h it .
3. Ut ilit y Applicat ion
•
•
•
•
•
PAGE 2 of 4
Th e c ondenser can sim ply be an invert ed lid t hat is fille d w it h a sufficient am ount of ice.
This w ill efficient ly c ondense t he solv ent v apor and also allow for a cent r al dr ip point .
The sam ple cup can be m ost any cont ainer t hat is porous, or m ade t o be so, and has
sufficient volum e t o hold t h e desired am ount of m at erial.
The sam ple cup filt er can be r egular filt er paper t hat has sufficient por e size and can
w it hst and t he solvent being used. As an alt er nat ive, a com m on t ea bag t hat is pr oper ly
rinsed is very robust for applic at ions requiring less t han 5 gram s of st art ing m at erial. I n
t his m anner one could em ploy a “ Sox t ec ” pr ocedur e and decr ease ext r act ion t im e and
allev iat e spill over.
The r eser v oir can be a r egular pot .
Ensur e t he heat sour ce is not flam e based if using volat ile solv ent s such as acet one or
m et hanol.
AN ABO LI CM I N D S. CO M
BEGI N N ER | I n t er m ediat e | Adv anced
Anabolicm inds Archive
BEGI N N ERS GU I D E T O SO X H LET EX T RACT I O N S
SOLV EN T EX T RACT I O N
A solv ent ext r act ion is any t echnique t hat is used t o separ at e or isolat e a species fr om a m ixt ur e of
com pounds or im pur it ies. This m et hod of separ at ion r elies on t he solubilit y char act er ist ics of t he
par t icular species inv olv ed.
A r at her gener al st at em ent of solut e/ solv ent solubilit ies can be st at ed by lik e dissolve s lik e . I n
ot her w or ds, a specie w ill dissolv e in a solv ent t hat is chem ically sim ilar t o it self. A com m on
exam ple of t his would be wat er and oil. The degr ee t o w hich one w ill dist r ibut e it self t o t he ot her
phase is r efer r ed t o as it s pa r t it ion coe fficie n t .
This coefficient is im por t ant t o det er m ining t he choice of solv ent s as each w ill v ar y for differ ent
spec ies. A giv en specie, w hen in a binar y sy st em of im m iscible solv ent s, w ill dist r ibut e it self
accor ding t o t he follow ing equilibr ium :
X
⇔
solvent1
X
solvent2
I t follow s t hen t he equilibr ium const ant be defined by :
K
[X
[X
≡
eq
solvent2
solvent1
]
]
I t should be not ed her e t hat w e ar e using concent r at ion inst ead of act iv it y coefficient s so as t o
keep t he m at erial sim ple.
I f equal por t ions of solvent s ar e used t his equat ion becom es:
K
≡
δ
δ
solvent2
solvent1
As an exam ple of use, assum e t hat specie “ TA” w as ext ract ed from an aqueous and et her solut ion.
A st ar t ing m ass of 1000 m g w as ex t r act ed w it h 100 m L of et her and 100 m L of w at er. Th e
m easur em ent w as t ak en aft er int im at ely m ixing by vor t ex or sim ilar m et hod and found t o hav e 800
m g par t it ioned int o t he et her layer.
K
ether / water
≡
C
C
800mg
ether
water
≡
100mL
200 mg
≡ 4
100 mL
This is an im por t ant concept as som e ar e under t he im pr ession t hat one ex t r act ion w ill suffice bu t
depending on t he par t it ion coefficient it m ay be incom plet e. As is ge n e r a lly t h e ca se , se v e r a l
sm a ll e x t r a ct ion s w ill y ie ld g r e a t e r r e cov e r y t h a n a sin g le e x t r a ct ion w it h la r g e a m ou n t s
of solv e n t . The at t r act iv e char act er ist ic of a Sox hlet ex t r act ion is t hat t he m at er ial is const ant ly
being elut ed w it h fr esh solv ent and est ablishm ent of [ solut ion] equilibr iu m is not a concer n.
PAGE 3 of 4
AN ABO LI CM I N D S. CO M
BEGI N N ER | I n t er m ediat e | Adv anced
Anabolicm inds Archive
BEGI N N ERS GU I D E T O SO X H LET EX T RACT I O N S
CH OI CE OF SOLV EN TS
This m ust be wit h considerat io n of m at er ials being separ at ed and t he degree t o w hich each w ill or
will not dissolve. As an exam ple for discussion, let ’s ex am ine t he binar y sy st em of an or ganic nonpolar m olecule such as cholest er ol in a m et hylcellulose m at rix.
Cholest er ol or ot her est er fied m olecule w it h a
st er oidal backbone
•
•
Gener ally NON- POLAR
Wat er I NSOLUBLE
Met hy lcellulose
•
•
FI GURE 1. 3 – St eroidal m olecule
FI GURE 1 . 4 – Met hy lcellulose
WATER SOLUBLE
Slight non- polar qualit ies
The m at erials in our exam inat io n lend t hem selv es t o solv ent ex t r act ion as t her e is sufficient
charact er difference t o at t ain exc ellent separ at ion w it h com m on solv ent s. One could use w at er t o
ex t r act t he m et hy lcellulose fr om t he st er oidal m at er ial.
As an alt er nat iv e one could use acet one but t he car bony l w it h heat m ay lend t o r eact ion w it h t h e
specie of int er est .
SUM M ARY
Alt hough w et chem ist ry m et hods w ill pr ovide decent ex t r act ion efficiencies t her e ar e fact or s t hat
m ay decr ease consist ency and pr oduct pur it y t hat is r elat ed t o bot h m an and m et hod. By using a
Sox hlet apparat us t o per for m t he ex t r act ions t he am ount of solv ent w ill be significant ly r educed,
consist ency im pr ov ed, and ov er all pr oduct qualit y ranging fro m 97 % t o 99% + pur it y . The basic
set up is sim ple and can be r eused as oft en as needed. The m at er ials can be conv enient ly locat ed if
not alr eady in possession and solvent s com m o n.
This m et hod is best em ployed by one t hat per for m s fr equent ext r act ions and desir e s high y ields.
PAGE 4 of 4
AN ABO LI CM I N D S. CO M
BEGI N N ER | I n t er m ediat e | Adv anced
BEGI N N ERS GU I D E T O SO X H LET EX T RACT I O N S
CH EM O
Adm inist r at or
Subm it t ed: Apr il, 2003
SUM M ARY
The ext ract ion m et hods present for m ost solid sam ples usually involve a subst ant ial am ount of w et
chem ist ry . I f one w er e not v er sed in t he chem ical ar t s it is har d t o be confident and pr oact iv e in
heading off exper im ent failur e due t o lack of educat ion, ex per ience, or under st anding. A viable
alt er nat iv e t o t he t r adit ional w et m et hods of solv ent ex t r act ion is a Sox hlet t y pe of apparat us w hich
allows for near 100% act iv e m ateria l recovery and user fr iendliness. Th e gen er al
I n t his m ini- ar t icle w e w ill explor e efficient solid- liquid ex t r act ions using a Sox hlet t y pe apparat us
and applicat ion of t heor y t o ut ilit y set ups.
GEN ERAL BACKGROU N D
The sim plest form of solid- liquid ex t r act ion is t he t r eat m ent of a solid wit h a solvent . An exam ple
of t his w ould be in separat ing a sand/ salt m ixt ure by using w at er. Sw ir l for a few m om ent s and
decant , or pour off, t he salt ( now in t he w at er layer) . The sand r em ains since it is I N SOLU BLE.
I n all solv ent ex t r act ions an at t em pt is m ade t o t ak e adv ant age of differ ences in solubilit y bet w een
t he species being separ at ed.
1. Soxhlet
Th e apparat us, first described in 1879, is a v er sat ile t ool
t hat can be used t o separ at e a single gr am t o hundr eds of
gr am s w it h near 100% r ecov er y .
FI GURE 1 . 1 – Ty pical Set up
The basic pr ocedur e calls for a solid sam ple t o be placed in
a por ous cont ainer and allow ing condensed solv ent t o
ex t r act cont inuously. The figur e on t he r ight show s t h e
basic com pone nt s of a Sox hlet apparat us:
•
•
•
PAGE 1 of 4
Con de n se r
Funct ion is t o cool t he solv ent v apor and cause it t o
c ondense ( t urn back int o a liquid) . Figur e 1.1
show s a r ing t y pe of condenser w hich funct ions by
incr easing t he sur face ar ea t hat can be used t o
t r ansfer heat . This is very sim ilar t o a h eat
ex ch an ger or aut om ot iv e r adiat or t hat is used t o
du m p ex cess h eat .
Po r o u s Co n t a in e r
Funct ion is t o hold t he solid sam ple and allow for
t he condensed solv ent t o sat ur at e and pass t hr ough
t her eby ex t r act ing act iv e m at er ial. This can be
likened t o a filt er in t hat it r et ains t he insoluble
com ponent s and allow s w hat ev er is dissolv ed t o
pass.
D ist illin g Pot
Funct ion is t o hold t he solv ent pool and ser ve as a
r eser v oir for t he concent r at ed m at er ial.
AN ABO LI CM I N D S. CO M
BEGI N N ER | I n t er m ediat e | Adv anced
Anabolicm inds Archive
BEGI N N ERS GU I D E T O SO X H LET EX T RACT I O N S
2. Basic Operat ion
The solv ent v apor , gener at ed by gent ly
heat ing t he r eser v oir, condenses and is
allow ed t o dr ip back ont o t he porous sam ple
cup.
FI GURE 1. 2 – Ut ilit y Set up
The liquid condensat e t hat dr ips ont o t he
sam ple per for m s t he ex t r act ion w hich t hen
passes t hr ough t he cont ainer and back int o
t he r eser v oir . The cy cle is r epeat ed
cont inuously and can be sust ained as long
as needed. As it progresses t he species of
int er est is concent r at ed in t he r eser v oir .
I n a r ev er se ex t r act ion t he species being
elim inat ed m ay be concent r at ed in t he
reserv oir inst ead. An exam ple of t his m ay
be t o use w at er as t h e solv ent w it h a
m et hylc ellulose based m at r ix t o be
ex t r act ed. I n t his scenario t he
m et hy lcellulose w ould be collect ed in t he
reservoir and t he act iv e species r et ained in
t he porous sam ple cup. As elim inat ion of
solvent m ay be a concer n for som e t his
met hod only uses w at er t o per for m t he
ext ra ct ion and is easily pushed off dur ing
com m on dr y ing pr ocedur es.
Rat e of r eflux is especially im por t ant her e as
low v apor pr essur e solv ent s such as acet one
or m et hanol m ay condense fast er t han t he
pass- t hr ough r at e. This w ill c ause t he level
of solvent in t he porous sam p le cup t o
accum ulat e and ev ent ually spill over t he
side possibly t aking m at er ial w it h it .
3. Ut ilit y Applicat ion
•
•
•
•
•
PAGE 2 of 4
Th e c ondenser can sim ply be an invert ed lid t hat is fille d w it h a sufficient am ount of ice.
This w ill efficient ly c ondense t he solv ent v apor and also allow for a cent r al dr ip point .
The sam ple cup can be m ost any cont ainer t hat is porous, or m ade t o be so, and has
sufficient volum e t o hold t h e desired am ount of m at erial.
The sam ple cup filt er can be r egular filt er paper t hat has sufficient por e size and can
w it hst and t he solvent being used. As an alt er nat ive, a com m on t ea bag t hat is pr oper ly
rinsed is very robust for applic at ions requiring less t han 5 gram s of st art ing m at erial. I n
t his m anner one could em ploy a “ Sox t ec ” pr ocedur e and decr ease ext r act ion t im e and
allev iat e spill over.
The r eser v oir can be a r egular pot .
Ensur e t he heat sour ce is not flam e based if using volat ile solv ent s such as acet one or
m et hanol.
AN ABO LI CM I N D S. CO M
BEGI N N ER | I n t er m ediat e | Adv anced
Anabolicm inds Archive
BEGI N N ERS GU I D E T O SO X H LET EX T RACT I O N S
SOLV EN T EX T RACT I O N
A solv ent ext r act ion is any t echnique t hat is used t o separ at e or isolat e a species fr om a m ixt ur e of
com pounds or im pur it ies. This m et hod of separ at ion r elies on t he solubilit y char act er ist ics of t he
par t icular species inv olv ed.
A r at her gener al st at em ent of solut e/ solv ent solubilit ies can be st at ed by lik e dissolve s lik e . I n
ot her w or ds, a specie w ill dissolv e in a solv ent t hat is chem ically sim ilar t o it self. A com m on
exam ple of t his would be wat er and oil. The degr ee t o w hich one w ill dist r ibut e it self t o t he ot her
phase is r efer r ed t o as it s pa r t it ion coe fficie n t .
This coefficient is im por t ant t o det er m ining t he choice of solv ent s as each w ill v ar y for differ ent
spec ies. A giv en specie, w hen in a binar y sy st em of im m iscible solv ent s, w ill dist r ibut e it self
accor ding t o t he follow ing equilibr ium :
X
⇔
solvent1
X
solvent2
I t follow s t hen t he equilibr ium const ant be defined by :
K
[X
[X
≡
eq
solvent2
solvent1
]
]
I t should be not ed her e t hat w e ar e using concent r at ion inst ead of act iv it y coefficient s so as t o
keep t he m at erial sim ple.
I f equal por t ions of solvent s ar e used t his equat ion becom es:
K
≡
δ
δ
solvent2
solvent1
As an exam ple of use, assum e t hat specie “ TA” w as ext ract ed from an aqueous and et her solut ion.
A st ar t ing m ass of 1000 m g w as ex t r act ed w it h 100 m L of et her and 100 m L of w at er. Th e
m easur em ent w as t ak en aft er int im at ely m ixing by vor t ex or sim ilar m et hod and found t o hav e 800
m g par t it ioned int o t he et her layer.
K
ether / water
≡
C
C
800mg
ether
water
≡
100mL
200 mg
≡ 4
100 mL
This is an im por t ant concept as som e ar e under t he im pr ession t hat one ex t r act ion w ill suffice bu t
depending on t he par t it ion coefficient it m ay be incom plet e. As is ge n e r a lly t h e ca se , se v e r a l
sm a ll e x t r a ct ion s w ill y ie ld g r e a t e r r e cov e r y t h a n a sin g le e x t r a ct ion w it h la r g e a m ou n t s
of solv e n t . The at t r act iv e char act er ist ic of a Sox hlet ex t r act ion is t hat t he m at er ial is const ant ly
being elut ed w it h fr esh solv ent and est ablishm ent of [ solut ion] equilibr iu m is not a concer n.
PAGE 3 of 4
AN ABO LI CM I N D S. CO M
BEGI N N ER | I n t er m ediat e | Adv anced
Anabolicm inds Archive
BEGI N N ERS GU I D E T O SO X H LET EX T RACT I O N S
CH OI CE OF SOLV EN TS
This m ust be wit h considerat io n of m at er ials being separ at ed and t he degree t o w hich each w ill or
will not dissolve. As an exam ple for discussion, let ’s ex am ine t he binar y sy st em of an or ganic nonpolar m olecule such as cholest er ol in a m et hylcellulose m at rix.
Cholest er ol or ot her est er fied m olecule w it h a
st er oidal backbone
•
•
Gener ally NON- POLAR
Wat er I NSOLUBLE
Met hy lcellulose
•
•
FI GURE 1. 3 – St eroidal m olecule
FI GURE 1 . 4 – Met hy lcellulose
WATER SOLUBLE
Slight non- polar qualit ies
The m at erials in our exam inat io n lend t hem selv es t o solv ent ex t r act ion as t her e is sufficient
charact er difference t o at t ain exc ellent separ at ion w it h com m on solv ent s. One could use w at er t o
ex t r act t he m et hy lcellulose fr om t he st er oidal m at er ial.
As an alt er nat iv e one could use acet one but t he car bony l w it h heat m ay lend t o r eact ion w it h t h e
specie of int er est .
SUM M ARY
Alt hough w et chem ist ry m et hods w ill pr ovide decent ex t r act ion efficiencies t her e ar e fact or s t hat
m ay decr ease consist ency and pr oduct pur it y t hat is r elat ed t o bot h m an and m et hod. By using a
Sox hlet apparat us t o per for m t he ex t r act ions t he am ount of solv ent w ill be significant ly r educed,
consist ency im pr ov ed, and ov er all pr oduct qualit y ranging fro m 97 % t o 99% + pur it y . The basic
set up is sim ple and can be r eused as oft en as needed. The m at er ials can be conv enient ly locat ed if
not alr eady in possession and solvent s com m o n.
This m et hod is best em ployed by one t hat per for m s fr equent ext r act ions and desir e s high y ields.
PAGE 4 of 4
AN ABO LI CM I N D S. CO M
BEGI N N ER | I n t er m ediat e | Adv anced