Daily Operation of Technicon Autoanalyzer II
LTER-Geochemistry Lab
Start up:
NOTE: To save time, start a warm water bath to bring the reagents up to room temp. Takes about 15 minutes to
get hot water and about 20 minutes to warm the reagents.
1) Hook up the appropriate analysis module to
the colorimeter and the autosampler lines. Hook up bubble lines to air pumping lines on
the peristaltic pump. Check the pump
tubing diagrams in the Lab Methods Manual if you have any questions.
2) Place the appropriate pair of filters in
the colorimeter. Only the colorimeter in
the back will ever need to have the filters changed. The Nitrite/Nitrate module uses the 550 nm
filter for both Nitrite/Nitrate and Total Nitrogen analyses. The Silica module uses the 660nm filters; the
ammonia module uses the 630 nm filters; the phosphorus module uses the 880 nm
filters.
3) Fill the Milli-Q
reservoir 1/2 full with fresh Milli-Q water.
4) Check the waste carboy. Empty if it is 2/3 full.
5) Place the pump tubing reagent lines into
MQ while the reagents are warming up.
Place the sampler(probe) into the autosampler and let it run on MQ. Once the reagents have warmed up, move the
lines from the MQ tothe appropriate reagent bottles
(lines and bottles are labeled).
6) Turn on power switches at the outlet
board. Be sure the autosampler’s
power button is not engaged.
7) Install the platen plate on the
peristaltic pump assembly and run pump on high speed once to get reagents
flowing through lines.
8) Check
to see if all reagents are flowing smoothly through the pump lines. If not, change lines
position on the pump rollers or replace worn pump tubing.
9) After the bubbles in the lines are flowing
evenly and are uniform in size, turn on the colorimeter and plug in the heating
element(when needed).
Set STD. CAL. knob to value used on previous
analyses.
10) After 15 minutes, turn on the strip chart
recorder(s), and install the pen(s).
11) Use the baseline knob on the colorimeter to
establish a zero baseline.
12) Once a stable baseline has been established(usually 45-60 minutes), place the prepared tray
on the autosampler (a standard 1 and a Milli-Q sample should be
run first for calibration purposes).
Press down the autosampler power button.
13) When the calibration standard’s peak comes
through on the chart paper,
adjust the STD. CAL. knob on the colorimeter to attain a peak
height that is almost the full width of the chart paper at the peak’s
maxima. When the Milli-Q
sample is being recorded, adjust the baseline knob of the colorimeter to place
the recorder pen at its original zero position.
14) You now have the system calibrated and
should not need to adjust the STD. CAL. knob the remainder of the
analysis. If the baseline drifts up or
down significantly over the course of the analysis, you may adjust it with the
baseline knob when a Milli-Q sample is being
detected. Record the adjustment with
an arrow on the strip chart and label it with a message.
15) A full tray takes one hour and twenty
minutes to be sampled completely. To
assure that the autosampler stops at the end of the
tray, place the red peg in the hole by the second-to-last sample
cup. Continuous analysis may be
maintained by taking the peg out and being sure to replace the sampled tray
with an unsampled tray after the last sample has been
aspirated.
16) Label the strip chart(s) with the name of
the analysis, date, and analyst.
Shut down:
(Takes 30-40
minutes at end of analysis.)
0) Remove the cadmium
column from the nitrate module without introducing any air into the column.
1) Remove reagent lines to a beaker filled
with clean Milli-Q water. Run the pump on high speed one time. Place reagent bottles back in the walk-in
cooler.
2) Remove the reagent lines to the small
bottle half-filled with 0.1 N NaOH solution. Run the pump on high speed one time.
3) Remove the reagent lines to the beaker
filled with Milli-Q water and run the pump one time
on high speed.
4) Remove the
reagent lines to a small bottle half-full of 0.1 N HCl. Run the pump on high speed one time.
5) Remove the reagent lines to the beaker of Milli-Q water and run the pump two or more times on high
speed.
6)
Remove the reagent lines to a plastic
storage bag. Lift the autosampler
“probe” out of the wash receptacle.
Run the pump on high speed until liquid is no longer visible in the
glass coils or the colorimeter tubing.
7) Remove the platen plate assembly and use a
Kimwipe to clean the gray underside with isopropyl
alcohol.
8) Turn off the power button on the autosampler and shut off all outlet power switches.
9) Turn off the power on the chart recorder
and cap the recorder pen.
10) Check the waste carboy, empty if 2/3 full.
Additional Notes:
If
you are having problems with an unsteady or unusual baseline, the pump tubing
and/or the pumping action are suspect.
Most problems encountered are due to irregularities in the pumping
action from worn pump tubing or blockages/air leaks in the lines.
A
level but noisy baseline may be caused by a small air bubble caught in the
colorimeter’s detection pathway. This
may be “pulled through” by squeezing for a few seconds on the tube labelled TO PUMP
and then releasing. A noisy baseline may
also indicate worn pump tubing or a reagent which is precipitating.
If
you notice that liquid is dripping from the connecting lines of the mixing
module and the colorimeter, you have probably forgotten to add a detergent
(Aerosol 22 or Brij 35)to
your reagents. See the Lab Methods
Manual for details.
Tray Preparation for NO2&NO3/NH4
and ∑N/∑P Analyses:
1) Fill tray with conical-bottomed cups
2) Fill each cup
completely with 1 N HCl. (83 mls conc. HCl/L)
3) Aspirate the acid from each cup.
4) Fill each cup completely with fresh Milli-Q water.
5) Aspirate the Milli-Q
water from each cup.
6) Repeat steps 4 and 5.
7) Aspirate thoroughly any water droplets in
the bottom or
clinging to the sides of the cups. This
step is very
important!
8) Fill sample tray immediately with the
samples.
Tray Preparation
for BRSi and DRSi analysis:
1) Fill tray with flat-bottomed cups.
2) Fill the sample tray with samples. (No washes or rinses
are needed!)
last revision: 8/24/95 by James Thoyre
