-
- Posts: 83
- Joined: Sat Sep 26, 2009 9:54 am
.
Well, you bought steep car ...
I worked with some coulometric titrator to Fisher, but much more simple Russian model.
http://www.ecosolution.ru/catalog/page029.php
1) interface with a computer and weights. In the description given standard RS-232 interface. However, the cable wiring is unknown. It should be in the documentation for the device. We need also a program of data collection, most likely it will work with individual key-Guard to LPT or USB port.
2) In this unit there is an optional device for transferring water to the titration cell with compressed gas from the heated sample.
This is useful for example for the analysis of ( same) freeze-dried peptides or solid animal and vegetabile (such as cacao oil and palmic oil) oil and fat , full insoluble in KF reagent , or Na antibiotic salt (its generated shit
in katode after first sampe).3) The device requires a special reagent - a reagent neutralized Fischer, who he will pay , after read manuals .
Sold a commercial reagent, it is called, for coulometric titrator HYDRANAL ®-Coulomate 34807anode + 34 840 (with membrane) and 34 810 (without membrane) (Fluka, Riedel-de-Hean). See which cell you have in the description of the instrument.
To my titrant device (titrator) neutralisated KF can be made from all of the reagent to Fisher - need to add water into the cell, initially estimated the number of ml, and then bring out microsyringe until the reagent is not completely neutralized. Reagent began to lighten a dark-brown to orange, and its resistance decreases with Mohm to pounds, the voltage at the indicator electrode increases from 0 to 400 mV. You can have different figures. This point is subtle and must adapt his capture.
4) Standart - Fluka Hydranal Water Standart 1.00 34828 , or wather solution in methanol 1 mg per ml.
5)The coulonometric device is fantastically sensitive to moisture penetration, because it works on the border between normal and spent reagent to Fisher. Penetration of "fresh air" to any leak through the cell causes a drift of the baseline and falsh-start as result. Need determine baseline as write in instruction every day, good drift - not more 0.0001 mg water per second
6) You must use only well-dried dishes-150 C -2 hours at least. Can I use other bottles - yes of course. But you have to check the caliper according to their external dimensions - diameter, the diameter of the neck and height.
7)How to make a sample.
I make liquid samples with a syringe, according to the difference of weight. First you dial the sample into the syringe and weigh it, then puncture the membrane, and pour the sample. After that, weigh the syringe again. This technique has shown me my dear Jean Claude Argoud of Afssaps.
Natural that the solution you are preparing for mass.
8)The main cause of errors - the growth of shit on the electrodes and the membrane during electrolysis. He was even seen is a dark brown mass of sometimes crystalline, sometimes rubbery
I washed it this way - with alcohol and paper, then dip the electrodes and the membrane to potassium bichromate with sulfuric acid. After that - dry in GC oven buy 150 C.
However, you may have other electrodes, read the instructions.
PS - Judging by nick miro2009 (Miroslav? - Czech, Polish, Bulgarian), you can own the Slavic languages. I invite you to Russian Chemical Forum www. anchem.ru / forums
