Metrohm 719 S Titrino - Manual (Page 141)

6.3 User methods
719 S Titrino
137
6.3.5 "Br_No"
Determination of the bromine number in
petroleum hydrocarbons according to ASTM
D 2710-72, resp. ISO 3839:1996.
The bromine number is defined as the quan-
tity of bromine in mg which reacts with 100g
sample.
Electrode:
6.0308.100 double Pt-electrode, at measuring
input "Pol".
Titrant:
Solution of bromide/bromate,
c(BrO
3
– /Br – ) = 0.05 mol/L.
Dilute 5.1 g KBr and 1.4 g KBrO
3
separately in
water and make up to 1 L.
Solvent:
714 mL glacial acetic acid,
134 mL 1,1,1-trochloroethane,
134 mL Methanol,
18 mL w(H
2
SO
4
) = 0.2 (20%)
Sample:
Dissolve the appropriate amount of sample
(depending on the expected bromine num-
ber) in 20 – 100 mL solvent. Titrate blank
sample the same way.
Reference:
ASTM D1159-84
ISO 3839:1996
Metrohm Application Bulletin Nr. 177
– Result in mg bromine/100 g sample
– Sample size in g
– Consumption of blank sample in mL
– Normality of the titrant (0.05*titer)
– Molar mass of Br
2
* 0.05
– Dilution factor
'pa
719 S Titrino 18200 719.0021
date 2002-03-13 time 13:05 0
SET Ipol Br_No.
parameters
>SET1
EP at U 500 mV
dynamics 500 mV
max.rate 10.0 ml/min
min.rate 25.0 µl/min
stop crit: drift
stop drift 20 µl/min
>SET2
EP at U OFF mV
>titration parameters
titr.direction: -
pause 1 0 s
start V: OFF
pause 2 0 s
extr.time 0 s
I(pol) 10 µA
electrode test: OFF
temperature 25.0 °C
>stop conditions
stop V: abs.
stop V 99.99 ml
filling rate max. ml/min
>statistics
status: ON
mean n= 3
res.tab: original
>preselections
conditioning: OFF
req.ident: OFF
req.smpl size: value
activate pulse: OFF
------------
'fm
719 S Titrino 18200 719.0021
date 2002-03-13 time 13:05 0
SET Ipol Br_No.
>calculations
Br_No.=(EP1-C01)*C02*C03*C04/C00;0;
C00= 1.0
C01= 0
C02= 0.5
C03= 7.99
C04= 100
------------
'de
719 S Titrino 18200 719.0021
date 2002-03-13 time 13:06
SET Ipol Br_No.
def
>formula
Br_No.=(EP1-C01)*C02*C03*C04/C00
RS1 text Br_No.
RS1 decimal places 0
RS1 unit:
>common variables
>report
>mean
MN1=RS1
------------