I notice that, due to a required replacement of limits of detection with limits of quantification, the lowest reported level for Nitrate has risen from 0.59mg/l to 2.11mg/l. Now a result of <2.11mg/l will not quite meet the limit set in 23500-3. Has anybody resolved with ALS or are other labs reporting in a similar way?
A further question, that may answer the above. With the standard requiring <2mg/l as N and our ASL results presented as NO3, could anybody reference information as to if there is a conversion that needs to be applied (or are they the same in terms of Nitrate level?)
A limit of 2 mg/l of NO3 if reported as Nitrate (N) is equivalent to a limit of 9 mg/l of NO3.
Basically multiply the N limit by 4.5 to get the NO3 limit
Hence the Renal Association limits were 9 mg/l (NO3).
This was spotted by Gareth Murcutt many years ago and Lizzie Lindley concurred.
According to my GCE Chemistry it's all to do with atomic weights