Problems in swab recovery

I mainly deals with cleaning validation. We are analysing swab samples by TOC method.
During swab recovery we are not able to judge the carbon contribution by environment during drying of samples on ss plates. we found that envorinmental carbon is unevenly contributing during study.
Please suggest any method to lower down atmospheric carbon or any consideration.

[quote=sacnic]I mainly deals with cleaning validation. We are analysing swab samples by TOC method.
During swab recovery we are not able to judge the carbon contribution by environment during drying of samples on ss plates. we found that envorinmental carbon is unevenly contributing during study.
Please suggest any method to lower down atmospheric carbon or any consideration.[/quote]

Please elloborate your question.

Hallo,
As far as i understand in normal manufacturing and ordinary lab conditions it is not recommended now a days to determine swab recovery by using TOC method-due to its very complex nature.Recovery can be carried out which targets a specific substance adsorbed on the equipment surface and then assaying the same substance.
regards
Ken

[quote=sacnic]I mainly deals with cleaning validation. We are analysing swab samples by TOC method.
During swab recovery we are not able to judge the carbon contribution by environment during drying of samples on ss plates. we found that envorinmental carbon is unevenly contributing during study.
Please suggest any method to lower down atmospheric carbon or any consideration.[/quote]

Depends on whether you are using the direct TOC determination (combustion techniques, etc) and assaying the the swab directly, or indirect oxidation techniques where you extract the swab content into suitable solvent (i’m guessing in this case that you are using the oxidation technique with water as solvent, since combustion techniques are not recommended for Cleaning Validation due to reduced sensitivity and precision). If the oxidation technique is used, you need to sparge/purge all dissolved atmospheric CO2 and inorganic carbon species first. Most modern meters are able to automate this as per the USP general chapter. As Mr Nyongesa said, it is extremely difficult to do swab recovery for TOC due to the complexity of relating the carbon back from whence it came. However, if you make certain assumptions about the carbon (contamination) source, and are able to evaluate the carbon contribution from the swab, you should be able to apply TOC in your Cleaning Validation programme.

swab recovery By TOC can be done eaisaly.
in my previous company we used to do it this method only.

precautions to be taken is carbon contribution of all accessories like glasswares,SS Plate,shall be known.
and this procedure is to varried out in ambient conditions.

this method is repeted for three times and mean is to be calculated.

prasad