Precautions for routine maintenance of the Karl Fischer
Precautions for routine maintenance of the Karl Fischer analyzer:
1. Most instruments use a polarized double platinum electrode to measure voltage. After a period of use, some of the Karl Fischer reagents and samples will invalidate the electrode response, delay the endpoint recognition, and the endpoint color will turn brown instead of yellow, and the electrode must be cleaned. When cleaning, the electrode is usually placed in an ultrasonic cleaning bath with deionized water or ethanol for a few minutes; or in chromic acid for 60s, then rinsed with deionized water or ethanol (dried before use).
List the types of contaminants and their cleaning methods.
Contaminant cleaning method
Contaminant type: cleaning agent
a mixture of fat, oil, chloroform and toluene
Polar substance, dimethylformamide
Salt, sugar formamide
Resin polymer material, alcohol, acetone, ether
Pigment material, dilute bleach
2. Under normal circumstances, the drift value of the instrument is a few microliters per minute (refer to the amount of Karl Fischer reagent consumed per unit time in order to keep the titration cell dry; this reagent is used to titrate the titration cell on the one hand) Moisture, on the other hand, compensates for the consumption of iodine caused by slow side reactions). If the drift value becomes large, it is necessary to check the leakiness of the moisture analyzer or consider the regenerated molecular sieve. During regeneration, the molecular sieves were placed in a drying oven at 160-300 ° C for at least 24 h. The molecular sieve installed on the waste water bottle contains water and sulfur dioxide, so it must be washed with distilled water before regeneration.
3. The burette is cleaned with an ethanol solution. Do not place the burette where the temperature is above 40 °C. O-rings and rubber pads for connection should not be placed in an organic solvent.
4. Moisture Analyzer There is a self-test system inside the instrument. If the instrument fails, the corresponding fault signal will be given. Users can refer to the instrument manual to understand the cause of the malfunction and eliminate it in a targeted manner.
5. The instrument must be placed in a dry and clean environment and arranged for special person to keep it; if it is not used for a long time, all the reagents in the instrument must be taken out, and all the pipes should be cleaned and stored in air.
1. Most instruments use a polarized double platinum electrode to measure voltage. After a period of use, some of the Karl Fischer reagents and samples will invalidate the electrode response, delay the endpoint recognition, and the endpoint color will turn brown instead of yellow, and the electrode must be cleaned. When cleaning, the electrode is usually placed in an ultrasonic cleaning bath with deionized water or ethanol for a few minutes; or in chromic acid for 60s, then rinsed with deionized water or ethanol (dried before use).
List the types of contaminants and their cleaning methods.
Contaminant cleaning method
Contaminant type: cleaning agent
a mixture of fat, oil, chloroform and toluene
Polar substance, dimethylformamide
Salt, sugar formamide
Resin polymer material, alcohol, acetone, ether
Pigment material, dilute bleach
2. Under normal circumstances, the drift value of the instrument is a few microliters per minute (refer to the amount of Karl Fischer reagent consumed per unit time in order to keep the titration cell dry; this reagent is used to titrate the titration cell on the one hand) Moisture, on the other hand, compensates for the consumption of iodine caused by slow side reactions). If the drift value becomes large, it is necessary to check the leakiness of the moisture analyzer or consider the regenerated molecular sieve. During regeneration, the molecular sieves were placed in a drying oven at 160-300 ° C for at least 24 h. The molecular sieve installed on the waste water bottle contains water and sulfur dioxide, so it must be washed with distilled water before regeneration.
3. The burette is cleaned with an ethanol solution. Do not place the burette where the temperature is above 40 °C. O-rings and rubber pads for connection should not be placed in an organic solvent.
4. Moisture Analyzer There is a self-test system inside the instrument. If the instrument fails, the corresponding fault signal will be given. Users can refer to the instrument manual to understand the cause of the malfunction and eliminate it in a targeted manner.
5. The instrument must be placed in a dry and clean environment and arranged for special person to keep it; if it is not used for a long time, all the reagents in the instrument must be taken out, and all the pipes should be cleaned and stored in air.
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