LC Isolink Liquid Chromatography Operation LC Startup Overview
Note: When operating: Total combined flow of MS pump, oxidation pump, and acid pump cannot exceed 700
µl/min. Over-pressuring the line can damage the Isolink separation unit. Isolink Operational Settings
************************************************************************ LC Shutdown Overview
************************************************************************ Maximum Flow Rate (Pumps)
************************************************************************ Detailed LC
Instructions
i. Slight
Vacuum: Apply a slight vacuum.
ii. Ultrasonic
Bath: Treat the reagents in an ultrasonic bath at this slight vacuum and
30 ¼C-40 ¼C. CO2 dissolved in the liquid will thus be volatilized. As both
oxidation reagent and acid/catalyst mixture are acidic media, nearly no CO2 will be
re-dissolved.
iii. Helium
Stripping: As a protective measure, perform a slight helium stripping using
e.g. a capillary that is directly introduced and continuously fed with helium.
The helium atmosphere prevents re-gassing, and dissolved CO2 will thus be
stripped out of the liquid. The same procedure is valid for the water at the
HPLC pump, which even is already equipped with a degasser: in addition to this
degasser, it is necessary to degas the water before use (first via slight
vacuum followed by ultrasonic bath and concluded by helium stripping). Leave the water under a
helium atmosphere by providing a constant helium stream.
i. Backpiston Flushing of HPLC Pump
ii. Bacteria Note: If the CO2 background signal
nevertheless is still considerably high after purging with water, eliminate remaining
bacteria by oxidation: therefore, purge the HPLC unit including the HPLC pulse
damper with oxidation reagent daily before measurement. A lower concentration
of M2S2O8 (M+ = Na+, K+, NH4+) than that used for
measurements is sufficient, e.g. 50-100 g/l. Finally purge several times using
pure water.
i. Fill the solvent
bottle(s) with degassed water and/or water inorganic solvent mix.
ii. Insert the tip of a 10
mL syringe into the tubing that is connected to the wingnut of the LDA (liquid
displacement assembly).
iii. Open the wingnut by
turning it counter-clockwise.
iv. Turn-on the pump power.
v. Open direct control
software in Isodat. 1.
Enter
percentages of solvent lines (100% Line A if just water). 2.
Enter
flow rate to 2000 µL/min. 3.
Click
Start Run (blue triangle) to start pump flow. You
may need to stop the pump to empty the syringe periodically. 4.
After
purging is complete, stop the pump and close the wingnut.
i. Fill the solvent
reservoir with degassed water, or weak inorganic oxidizing solution.
ii. Make sure a flow
restrictor or HPLC column is attached to the pulse dampener outlet
iii. Insert the tip of a 10
ml syringe to the manual bleed valve of the pulse dampener, and then open the
wingnut by turning it counter-clockwise.
iv. Set the pump flow to
1000 µl/min.
v. Fill the loop completely
to expel any air bubbles that may be in the line, or continue flushing to free
the lines of bacteria followed by a degassed water (solvent) flush.
vi. Set the pumprate to the
appropriate for the application.
vii. After the Pulse Dampener
has been refilled with degassed wager, close the manual feeder valve (wingnut
clockwise).
i. Cut the 1/8Ó OD x 1/16Ó
ID PTFE tubing of the outer loop of the piston.
ii. Connect a syringe filled
with degassed HPLC grade water to the bottom piece of the tubing and gently
flush water through the system.
iii. Reattach a new piece of
tubing (DO I NEED TO FINISH BY PUSHING AIR THROUGH THE SYSTEM WHEN DONE
FLUSHING????).
i. Rinse the
containers using LC-grade solvent to remove any dust.
ii. Fill the
containers with appropriate LC-grade solvent.
iii. The bottle
caps are pre-assembled to include an inlet line and filter. Ensure that each
filter is tightly assembled to its fitting, and that the filter fitting is
firmly attached to the inlet line. Mace the solvent filter inlet line into each
bottle, making sure that the inlet filter rests on the bottom of the bottle.
Cap the bottle.
iv. Attach the
appropriate label to each solvent bottle cap to identify it.
v. Run vent
lines from each bottle to an appropriate exhaust apparatus.
i. oxidation
reagent 1.
200 g/l M2S2O8 (M+ = Na+, K+, NH4+);
this will yield a strongly oxidative solution. 2.
For UCSC test: 40 gm Na2S2O8 was
dissolved in 200 ml H2O. However, what ultimately worked best was
dissolving 15 g Na2S2O8 in 500 ml H2O. 3.
If no AgNO3 catalyst is used, increase the
concentration to 50 gm Na2S2O8 in 200 ml H2O.
4.
Measure water using a graduated cylinder.
ii. acid 1.
1.5 molar solution of H3PO4 in water
iii. catalyst 1.
Catalytic amounts of solid AgNO3 are used, e.g. three tips of
spatula in 200 ml water. Compared to an aqueous solution of AgNO3, solid AgNO3 is
advantageous, as: a.
no impurities due to
additional water will enter the system and b.
no additional water needs to be degassed.
iv. The acid/catalyst
mixture is composed of: 1.
aqueous
85% ortho-phosphoric acid, H3PO4 2.
silver
nitrate, AgNO3. Silver ions (Ag+) are catalytically
active as they temporarily fix oxygen and transfer it to the organic compounds.
These, in turn, will be oxidized to CO2. 3.
Warning. In case of
sulfide- or halogenide-containing samples, e.g. chloride in seawater, do not
use silver nitrate, AgNO3, as an oxidative catalyst! As precipitates, sparingly soluble
silver sulfide, Ag2S or silver halogenides, AgX would be formed causing damage to the
separation unit. 4.
These
are the recommended acid/catalyst concentrations given by Dieter (of Thermo-Bremen), as relayed to UCSC
by installation engineer Burt Wolff.
v. Note. It is unreasonable to
recommend any generally accepted concentration values. Rather, the optimum
concentrations of all reagent components must always be determined empirically.
vi. Principle: On the one hand, oxidation
reagent concentration must be sufficiently high to ensure complete oxidation
(check via oxygen background; see Oxygen Background (m/z 32) on page 7-6).
vii. If its concentration is too
high, however, the solutions show increased viscosity. Therefore, they are more
difficult to be pumped, and lifetime of the system might be reduced due to
corrosion.
i. double peaks (a small
peak is followed by a big one)
ii. peak broadening
iii. extraordinary long
tailing (additionally, δ 13C
values may diverge).
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![]() NEWS & EVENTSUCSC's Stable Isotope Laboratory operations are back to full operations following the Covid-19 shutdown. Please contact the lab if you are interested in our services. SIL Co-Director Matt McCarthy directed a weekend program for about 20 Educational Opportunity (EOP) STEM transfer students highlighting the use of stable isotope analyses in phyiscial and biological science inquiry. UCSC's Stable Isotope Laboratory welcomes new Ocean Sciences faculty member Pratigya Polissar. Dr. Polissar will join the SIL as a co-director SIL Co-Founder Paul Koch and colleagues review Sundance Film Festival movies for Science magazine. SIL Co-Director Matt McCarthy recieved a NSF Major Research Instrumentation award for new compound specific isotope ratio mass spectrometers. SIL Co-Director Matt McCarthy directed a weekend program for about 40 Educational Opportunity (EOP) STEM transfer students highlighting the use of stable isotope analyses in phyiscial and biological science inquiry. SIL Co-Director Jim Zachos appointed to Ida Benson Lynn Endowed Chair in Ocean Health. UC Santa Cruz biologists Daniel Costa and Luis Huckstadt found valuable samples for comparison of modern Weddell seals to century-old pelts found in the huts of Antarctic explorers Ernest Shackleton and Robert Falcon Scott. Their findings reveal changes in the Ross Sea ecosystem. SIL Co-director Jim Zachos elected to be a member of the National Academy of Sciences! UCSC Stable Isotope Laboratory data used to show threatened grizzly bears in Yellowstone National Park have a vital hankering for a dwindling supply of pine nuts. SIL Co-director and UCSC Physical and Biological Sciences Dean Paul Koch has been elected 2015 AAAS Fellow for "energetic and innovative leadership in applying stable isotope geochemistry to document and interpret environmental change through the past 65 million years of Earth history.". SIL Co-director Jim Zachos has been awarded the 2016 Milutin Milankovic Medal by the European Geosciences Union. Formation of coastal sea ice in North Pacific drives ocean circulation and climate. So indicates evidence published by UCSC scientists Karla Knudson and Christina Ravelo. Christina Ravelo, Professor of Ocean Sciences at UC Santa Cruz and UCSC Stable Isotope Laboratory co-director, has received the 2013-14 Outstanding Faculty Award from the Division of Physical and Biological Sciences. The annual award is the division's highest honor for faculty achievement, recognizing combined excellence in research, teaching, and service. Long-term human influenced dietary habits of Yosemite National Park black bears explored by UCSC scientist Jack Hopkins, Paul Koch, and colleagues. SIL Co-Director Paul Koch honored as a Fellow of the California Academy of Sciences. See story here. Diversity of great white shark diet was shown to be greater than previously thought based on research by UC Santa Cruz colleagues Sora Kim, Paul Koch, and James Estes along with co-author M. Tim Tinker of the U.S. Geological Survey. This work was highlighted in the Los Angeles Times. SIL Co-Director Paul Koch has been named Dean of the UC Santa Cruz Division of Physical and Biological Sciences. Madagascar Lemur extinctions and ecological retreat followed arrival of humans according to UCSC Graduate Student Brooke Crowley, Professor Paul Koch and co-authors. Their findings were recenlty published in the journal Proceedings of the Royal Society B. SIL Co-Director Paul Koch was quoted in the New York Times on research showing that a tiny Paleocene horse Sifrhippus, the first horse, grew even smaller during the Paleocene-Eocene Thermal Maximum climatic warming event. SIL Co-Director Christina Ravelo has been selected as an American Geophysical Union (AGU) Fellow. SIL Co-Directors Paul Koch and Jim Zachos's research on Paleocene-Eocene Thermal Maximum (PETM) climatic warming event is featured in an National Geographic article "Earth Before the Ice" in the October 2011 issue. SIL Co-Director Paul Koch has been appointed Interim Dean of the UC Santa Cruz Division of Physical and Biological Sciences. SIL Co-Director Jim Zachos elected to the American Academy of Arts and Sciences. UCSC's SIL new ThermoScientific MAT 253 isotope ratio mass spectrometer coupled to a Kiel Automated Carbonate Device begins regular operations. UCSC's SIL retires its 15 year-old dual-inlet Optima following a very productive career. The instrument generated over 40,000 data points. Two Tsavo Lions In Famed Killings Get Partial Reprieve according to UCSC Graduate Student Justin Yeakel. Listen to Justin's inteview on National Public Radio's All Things Considered: SIL co-director Christina Ravelo (Ocean Sciences) sails as co-chief scientist on Integrated Ocean Drilling Project (IODP) Expedition 323 to investigate Bearing Sea Paleoceanography.
SIL co-director Christina Ravelo (Ocean Sciences) gives the 2008 Emiliani Lecture at the American Geophysical Union Meeting in San Francisco on "Lessons from the Pliocene Warm Period and the Onset of Northern Hemisphere Glaciation".
UCSC SIL has been funded by the National Science Foundation for a new Dual-Inlet Isotope Ratio Mass Spectrometer with individual acid drip system for very small calcium carbonate samples. SIL co-director Jim Zachos (Earth and Planetary Sciences) recieves prestigious Humbolt Research Award. See Humbolt Award for details. SIL Co-Director Jim Zachos has been selected as an American Geophysical Union (AGU) Fellow. In recognition of the new continuous flow instruments added to the UCSC stable isotope facility a Symposium is being run to highlight the new analytical capabilities. |