[Melissa]

 I am studying the preservation of samples of water by constituent. I am reading and understanding the table 1060 I in the Standard methods ed 23th. The last columns of table are: 1) preservation 2)Maximum Storage Recommended 3)Regulatory

In case of the determination of alkalinity in water:

Preservation                                Maximum Storage Recommended                           Regulatory
  Cool, >=6°C                                                          24 h                                                                   14 d

In my experience and related information about it,  total alkalinity must be analyzed immediately because there are solved gasses in water samples.  but what it means "regulatory in 14 days"?
Maybe it could be that water samples are sealed and do not open for the next 14 days  and preserved at 4°C.

[sjb]

Duplicate - see also http://www.chemicalforums.com/index.php?topic=96720.msg342294

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