Tiêu chuẩn iso 01271 1983 (1985) scan

I nternational Standard @$ 1 271 0 N 4 d! igib I NTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEX~YHAPOL\HAR OPTAHMBAt&lR fl0 CTAH/JAPTM3A~I IM~ORGANlSATlON I NTERNATIONALE DE NORMALISATION Essential[.]

INTR ATIO AL O GNIZATIO FO STADR IZATIO MEX~Y HA L\HR OTAMBt&lR fl0 CTA /JATM3A~IM~OGA NlSTlO INTR ATIO AL DE N RMALISTIO

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De criptors : es ntia l ois, c emical a na lyis,

d termina tio of c onte t, ca rbo yl c mpo n s

IS0 (h Internatio al Orga niza tio for Standardizatio ) is a worldwid fe eratio of

natio al standard b odie (IS0 member b odie ) T he work of p reparin Internatio al

bo y intere te in a s b je t for whic a te h ical c m ite has be n e tab lis e ha s

th rig t to be rep re e te o that c m ite Internatio al organizatio s, g v ern-

me ta l an n n-g v ernme tal, in lais n with ISO , als ta ke p art in th work

th member b odie for app rov al b efore th ir a cc ptanc a s Internatio al Sta nda rd by

least 75 % a p p rov al by th member b odie v otin

Ese tial ois

ca nc ls a nd rep lace th first e itio , o f whic it c ntitute a te h ical rev isio

Essentia l oi s - Determina tion of ca rbonyl va lue

T his Internatio al Stan a rd spe ifie a meth d for th d ter

mina tio of th ca rbo yl v a lu of e s ntia l ois It is a pplca b le

to es ntia l ois whic c nta in ca rbo yl c mpo n s (e pe ia lly

k to e , e clu in meth lketo e ) whic a re dific ult to c n-

T he meth d is n t applca ble to e s ntia l ois whic c nta in

s b sta ntial amo nts of e ters or oth r a lkali-s n itiv e c n ti-

tu nts

Internatio al Sta ndard spe ifyin re uireme ts for in iv id al

e s ntia l ois wi spe ify wh th r this meth d or th h dro -

p lic able

IS0 212, Es e tia l ois - Sampln

IS0 3 6, Es e tia l ois - Prep a ratio of tet sample

3 Definition

F or th purpo e of this Internatio al Sta nda rd, th folowin

d finitio app lie

c a rbo yl v a lu (of a n e s ntial oi) : T he n mber of mi grams

o f potasium h dro id , per gram of e s ntia l oi re uire to

n utaliz th h dro hloric a cid lb erate in th o imatio rea c-

NOT - Oxime are th re ult of th reactio of ca rbo yl c mpo n s

with h dro ylamin

4 Princ ip le

with fe h dro ylamin lb erate in a mixture of h dro ylam-

Titatio of th e c s a lkali with h dro hloric a cid s lutio ,

eith r ca lorimetica lly or p ote tiometically

Al rea ge ts s a ll be of re o niz d a na lytical gra de a nd th

w er u e s a ll be disti e w er or w er of at least e uiva le t

p urity

5.1 Hy ro hloric acid, sta nda rd v olumetic s lutio ,

c(H I) = 0,5 mol/ l

in 9 % ( V/ VI ethanol

5.3 Bromoph n l b lu , etha nolc s lutio

Disolv e, by h atin , 0,2 g of bromoph n l b lu in 3 ml of

a nd 10 ml of 9 % ( Vl VI ethanol Afer c ooln , diute to

Dis olv e 5 g of h dro ylam o ium c lorid in a ppro im ely

10 ml of w er, a dd abo t 8 0 ml of 9 % ( V/VI ethanol

a nd diute to 1 0 0 ml with 9 % ( V// / v ) ethanol A dd th

is gre n, if th lq id is obs rv ed in a thin la yer, or u ti re , if

th la yer is thic k

A lemo -y low c lo r s a ll be ob tain d wh n 0,0 ml of th

h dro hloric a cid s lutio (5.1) is a dd d to 2 ml of th s lu-

tio , a nd a re c lo r s a ll be ob tain d wh n 0,0 ml of th

potasium h dro id s lutio (5.2) is a dd d to a noth r 2 ml of

th s lutio

The s lutio is sta b le for o e we k

1) IS0 129, Esentia l ois - Determina tion of c a rbny l v a lue - Hyroxla mmonium cloride method

6 Ap aratu

Us al laoratory e uipme t, a nd in p ric ula r

6.1.1 Glas flas s, alkal-e istant, of ca acity 10 to 2 0 ml

with glas tube at least 1 m lo g a nd a t least 10 m in interna l

diameter to s rve as reflu c on e s rs

6.1.2 Pipete , of c ap c itie 2 a nd 5 ml

6.1.3 B urete , of c apc ity 2 ml gra dua te in 0, ml divi-

sio s

6.1.4 Analytic al b lanc e

with c ombin d glas elec tro e

6.2.2 Mag etic stirer

Se IS0 212

Se IS0 3 6

8.2 T est p rtion

Weig , to th n a re t 1 mg, into a flas (6.1 ) a mas m of th

spec ific atio for th e s ntial oi c onc ern d

Simultan o sly with th d terminatio , c ary o t a blan te t

omitin th tet porio

If h tec hniq e by pote tiometic tita tio is u e (s e 8.4.2) it

is impora nt tha t th blan te t im e iately prec ed s th d ter

minatio , in ord r to opera te a t th same tempera ture

8.4 Determination

8.4.1 C alorimetic tita tio

Tran fer, by mean of a pipete (6.1.2), 2 ml of th hy drox -

ylam o ium c hlorid s lutio (5.4) into th flas (6.1 ) c on-

hydrox id s lutio (5.2) meas re fom a pipete or a b urete

a nd mix A llow th flas c ontainin th mixture to stan , or boi

u d r reflux , f or th time spec ifie in th Interna tio a l Stan-

dard spec ific atio f or th e s ntial oi c onc ern d If boi n is

c arie o t, c ool ra idly bef ore remov in th reflu c on e s r

Titate with th hy droc hloric ac id s lutio (5.1) u ti th

gre nis -yelow e d-point is obs rved T he tita tio s o ld be

c a rrie o t in a loc atio tha t is wel i uminate by na tura l

daylig t

NOT - T his method is aplc able to lg tly c oloured esentia l ois F or

stronly c oloured esentia l ois, the ptentiometric method spc ified

in 8.4.2 or, if a ptentiometer is not a v aia ble, the modified proc ed re

desc ribd in the an ex sould b ued

8.4.2 Pote tiometic tita tio

Tra nsfer, by mean of a pipete (6.1.21, 5 ml of th hy drox -

a noth r pip ete, 2 ml of th etha nolc potas ium hydrox id

s lutio (5.2) Clo e th flas with its glas stop er a nd mix th

c onte ts wel by swirln A llow th mixture to stan a t ro m

temperature, or boi u d r reflux , f or th time spec ifie in th

Interna tio a l Stan a rd spec ific atio for th e sntial oi c on-

c ern d

Tita te pote tiometic aly with th hy droc hloric ac id s lutio

(5.1 , whie stirin with th mag etic stirer (6.2.21.1) T he u e

of a rec ordin pote tiometer wi greatly simplfy this opera tio

C alc ulate th v olume of hy droc hloric ac id s lutio u e a t th

e uivale c e-point fom th tita tio c rv e or fom readin s of

th c han e in pH It s o ld be emphasiz d tha t, ac c ordin to

alway be th same s that tita tio to a fix ed pH valu is ex -

c lu e

The c arbo yl valu , ex pre s d in mi grams of potasium

hydrox id per gram of e s ntial oi is giv n by th formula

5 , x (Vo- V l)

x

m

wh re

c is th ex ac t c onc entatio , in mole per lte, of th

hydroc hloric ac id s lutio (5.1);

I The method for the ptentiometric titra tion of esential ois wi form the sbjec t of IS0 42

m is th mas, in grams, of th tet p orio (8.2);

k ’c is th v olume, in mi lte , of h dro hloric a cid s lu-

tio (5.1) u e in th bla nk te t (8.3);

V , is th v olume, in mi lte , of h dro hloric a cid s lu-

T he carbo yl c mpo n s c onte t, e pre s d as a sp ecifie

a ld h d or k to e as a perc nta ge by mas , is giv en by th

formula

wh re

c, m, Vc a nd VI hav e th same meanin s as a b ov e;

k to e spe ifie in th Internatio al Sta nda rd sp ec ificatio

for th e s ntia l oi c n ern d

Expre s th re ult to two sig ific a nt fig re

10 T est re ort

T he te t rep or s all state th meth d u e an th re ult ob-

spe ifie in this Internatio al Sta nda rd, or re a rd d as op-

tio al, as wel as a ny circ mstan e that mig t ha v e influ nc ed

th re ults

The tet rep or s a ll in lu e all d tails re uire for th c mplete

id ntific atio of th sample

Annex

(T his an e forms a n inte ra l part of th Sta ndard.)

Tran fer, by mean of a pipete (6.1.2), 2 ml of th hy drox -

ylam o ium c hlorid slutio (5.4) into a flas (6.1 1 Add

15 ml of th potasium hydrox id s lutio (5.2) fom a pipete

or a burete a nd mix

a nd reta in th emptie c nic al flas with ut was in it Allow

th flas c onta inin th mix ture to stan , or boi u d r reflux ,

f or th time spec ifie in th Interna tio a l Sta nda rd spec ific atio

for th e s ntial oi c onc ern d If boi n is c a rrie o t, c ool

gre nis -y elow e d-point is obs rv d

Tranfer a bo t ha lf of th c onte t to th origina l flas ,

ta nsfer to th oth r flas, mix, a nd aga in return o e ha lf of h

s lutio to th original flas

Repeat this opera tio u ti th a dditio of two drops of th

hy droc hloric ac id s lutio (5 I) to th s lutio c ontain d in o e