Discussion Category: Titrators
INCOSISTENT RESULT FROM 848 TITRINO PLUS METROHM
Currently having issues with the titration results of my 848 Titrino plus. The equipments mosty display very low result like 0.8 when it is obvious that the result is above that.. sometimes, the result is higher, while at other times no result. During the course of all this, the samples are the same, including the reagents chemicals. Please i need your prompt response .
Reply byDear Sir
Please tell me what type of titration you are doing. Which type of eletrodes you are using. What is the titrant (incl. concentration).
Please add method parameters as well.
Best regards
Markus Laeubli, Metrohm International Headquarters
Reply byThe Titration is the determination of TBN result, using Automated titration method. the electrode is a PH electrode with tetra ethyl ammonium bromide(TEAB) as electrolyte. The titrant is a 0.1N HClO4(perchloric acid solution). Titration solvent is a solution of 40ml of chlorobenzen and 20ml of glacial acetic acid. the titrant is prepared by mixing 8.5ml of HClO4 ,500ml of glacial acetic acid and 35ml acetic anhydride, diluted to 1 litre with glacial acetic acid. the sample size is 1gramm. formular = (EP1* conc.*56.1)/Coo. where Coo =1=sample size.Method parameters; start conditions.
Activation pulse= off
start delay time=0s
start volume = 0.00000ml
pause=0s,request sample ID=off, request sample size = on
Titration parameters; titration rate= optimal, temp. = 25degrees, sensor=metal electrode, solution= HClO4, Stirrer=on, stirring rate=6
Stop conditions; stop volume=5ml, stop EP = 1, volume after EP=1ml, stop time=off, filling rate=20ml/min,
Evaluation; window off, EP criterion=30mv, EP recognition= all, fixed EP1 = off, fixed EP2 = off
Calculation; R1;TBN, R1=EP!*conc*56.1/coo. thankss for your time
Reply byDear Sir
I will discuss this item with our titration specialists. I will come back asap.
Reply byAgain, I need broader explanation on electrode types used in 848 titrino plus. like the reference electrodes
Reply byI checked about the electrodes for your application on the "Electrode Finder" and got only one hit in two versions:
Solvotrode easyClean 2 m cable
Have a look to the two electrodes, you will find a lot of information under these links.
Do not hesitate to contact your local Metrohm representative for more details.
Reply byMy titration colleagues asked for further information.
Would you mind to export some determination files on an USB stick and send it to us. The settings for the export can be found on pages 63 „PC/LIMS report“ in the 848 manual.
Best regards
Markus Laeubli
Metrohm AG
Ionenstrasse
CH-9100 Herisau
Switzerland
Reply bygood day, thanks for your prompt response, pls I think what I need is the parameter settings fot MET or DET titration method. I am currently using MET titration method to determine my TBN.
Reply byMode
DET U
Meas. point density
4
Min. increment
50 µL
Max. increment
100 µL
Signal drift
10 mV/min
Max. waiting time
60 s
Stop EP
off
EP criterion
10
EP recognition
greatest
BlankMode
DET U
Meas. point density
4
Min. increment
10 µL
Max. increment
50 µL
Signal drift
10 mV/min
Max. waiting time
60 s
EP criterion
5
EP recognition
all
Sample
Mode
DET U
Meas. point density
4
Min. increment
10 µL
Max. increment
0.5 mL
Signal drift
10 mV/min
Max. waiting time
20 s
EP criterion
15
EP recognition
all
Reply byI am experiencing another problem with my 848 Titrino plus , each time I press the start button to start a titration, this message pops up " THE PRINTER IS NOT CONNECTED OR SWITCHED OFF". This normally prevent the determination. Please I need a solution for this.
Reply byPlease check your method and remove any printing command.