Important notes about changes
approved at the Fall 2003 NADP Technical meeting which impact 2004 data
(2004 data begins with this months report):
1) New Sample Type "WD": A new
sample type "Wet Diluted" (coded WD) was implemented at the CAL
on 1-5-2004. This replaced the "Wet Add" sample type (coded WA)
. This change was made in response to the CAL's 2002 on-site review by the
Network Operations Subcommittee. The review team asked the CAL to find a
better way to dilute low volume samples. The WA protocol required that low
volume samples (precipitation volumes of 8 to 35 mL after filtration at
CAL) be diluted by adding 50 mL of DI water to allow for a complete
analysis of all chemical parameters. Sample volumes in excess of 60 mL
(after dilution) were discarded prior to analysis. Using the new
procedure, low volume samples are diluted to a final volume of 50 mL using
DI water. Following this protocol, no portion of the sample is discarded
and adequate sample volume is obtained for analysis.
2) A new instrument was approved for the
analysis of the cations sodium (Na), potassium (K), calcium (Ca), and
magnesium (Mg). Effective 1-5-2004 Na, K, Ca, and Mg were analyzed by
Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES). This
instrument replaced Atomic Absorption Spectroscopy (AAS) for these
analyses. The CAL purchased a Varian Vista Pro ICP-AES in mid-2003 to
replace the AAS which was > 10 years old. Method parameters and
parallel sample analyses were evaluated for several months, and results
were reported to NOS at the Fall 2003 meeting. The NADP approved the
change to ICP-AES beginning January 2004.
3) Bucket/Lid bags: For several months the CAL
has been working with a new vendor who can manufacture bucket and lid bags
with no background contamination. We recently switched to 2 mil thick bags
and have found that these are much easier to work with than the 2.75 mil
bags we were using last year. We'd like to hear your opinions about their
ease of use.
Please let us hear from you if you have any concerns or comments about
the new changes at CAL (cal@sws.uiuc.edu
).
