How much One Reagent is needed for a tray of 64 vials?
The amount of One Reagent used depends on several factors as described below. The QbD1200 monitors the One Reagent and will stop analyzing and display a warning on the screen if the One Reagent runs out.
The One Reagent is supplied in concentrated form in a 500mL bottle which has a 6 month shelf-life. For use in the QbD1200, the One Reagent is diluted, using just 10mL of One Reagent mixed with 990mL of low TOC water (<100ppb). The diluted One Reagent has a shelf-life of 7days.
Whilst the diluted One Reagent used in the QbD1200 has a 7 day shelf-life, it is expected that most QbD1200 users will make up a fresh bottle of diluted One Reagent with every tray of 64 samples to be analyzed.
The amount of reagent used can vary according to:
- The number of vials to be analyzed and number of analysis replications
For water samples with <4,000ppb TOC, just 2mL of One Reagent is consumed when analyzing each sample from the vials loaded into the autosampler. In addition, the sample line back-flush performed at the start of each new vial analyzed uses 5mL and 2 mL forward flush of One Reagent. So, for example, if the QbD1200 auto-ranging function was turned off and the autosampler was configured to analyze three samples from each vial, then analyzing each vial would consume:
Sample (3 x 2mL) + forward flush (3 x 2mL) + back flush 5mL = 17mL of One Reagent/vial
- If the auto-ranging function is enabled (if analyzing samples >4,000ppb TOC)
If the level of TOC in the vial is <4,000ppb, then each sample replicate uses just 2mL of One Reagent (plus the initial 5mL for line back-flush – see a) above). If the level of TOC is >4,000ppb, then the One Reagent will be used to dilute the sample, using a maximum of 9.6mL of One Reagent per sample analysis for water with >32,000ppb, plus an initial 9mL of reagent for auto-ranging for each vial.
