Care and use manual – Waters Sep-Pak XPoSure Aldehyde Sampler User Manual
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[ CARE AND USE MANUAL ]
VI. T ROUBLESHOOTING
Table 5 describes solutions to problems that may arise while
using the samplers. Most errors occur as a result of contamination
during sample preparation. To resolve chromatographic problems
not listed, refer to your HPLC system manual.
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Table 5: Troubleshooting
Symptom
Possible Cause
Solution
High carbonyl values
in sampler blank
Contaminated
acetonitrile
Certify acetonitrile quality
prior to use, see Appendix A.
Contaminated
glassware
Use only pre-cleaned
glassware.
Air contamination
during elution
Prepare sample in
a glove box.
Sampler age and
storage conditions
Replace samplers.
Refrigerate fresh samplers.
High formaldehyde
levels in sampler
blank
Coelution of
formaldehyde with
an impurity
Prepare a fresh mobile
phase or decrease the
acetonitrile content.
Broad peaks
Injection volume
too high
Reduce the
injection volume.
System or
column failure
Consult the HPLC
System manual.
VII. REFERENC ES AND BIBLIOGRAPHY
1. Committee on Aldehydes, Board of Toxicology and
Environmental Hazards, National Research Council,
Formaldehyde and Other Aldehydes; National Academy Press,
Washington, DC, 1981.
2. Tejada, S. B. “Evaluation of Silica Gel Cartridges Coated in
Situ With Acidified 2,4-Dinitrophenylhydrazine for Sampling
Aldehydes and Ketones in Air”, Intern. J. Environ. Chem.
1986, 26, 167-185.
3. Riggins, R.M. “Compendium of Methods for the Determination
of Toxic Organic Compounds in Ambient Air”, U.S.
Environmental Protection Agency Report EPA-600/4-84-041,
U.S. Environmental Protection Agency; Research Triangle Park,
NC, 1984.
4. Guide to Successful Operation of Your LC System; Waters
Corporation, Milford, MA 1991.
5. ASTM Method E411; Standard Test Method for Trace Quantities
of Carbonyl Compounds with 2,4-Dinitrophenylhydrazine.
VIII. ORDERING INFORMATION
Waters Sep-Pak XPoSure Aldehyde Samplers are shipped in boxes
of 20 individually-packaged cartridges. Pouches are supplied for
storage after sampling.
To order, contact your Waters representative, call Waters at
(800) 252-4752 or order online at
.
Table 6: Ordering Information
Product
Part Number
Sep-Pak XPoSure Aldehyde Samplers, 20/box
In-Line Pre-Column Filter
Symmetry C
18
Column, 3.9 x 150 mm
Solvent Filter, PVDF, 47 mm, 0.45 µm, Protein, 100/pkg
Beginners Guide to Liquid Chromatography
Guide to Successful Operation of Your LC System
IX. AP PENDIC ES
a. Appendix A: Measuring Acetontrile Purity
HPLC-grade acetonitrile may contain traces of aldehydes and
ketones, and especially acetone. A concentration of 10 µg/L of
an aldehyde or ketone in the acetonitrile adds 0.1 µg to the blank
values determined for the DNPH-derivatives per cartridge.
If you acetonitrile is unacceptable for your application, contact
your solvent supplier, to purify the acetonitrile. To purify
acetonitrile, distill it from an acidified DNPH solution, using a
procedure analogous to the one described in ASTM Method E411
for the purification of methanol.
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To measure acetonitrile purity:
1. Clean all glassware by rinsing with acetonitrile and heating
in a 60 °C vacuum oven for at least 30 minutes.
2. Elute a fresh sampler with 3 mL acetonitrile.
3. Within 3 minutes, inject the eluate into the HPLC system to
measure the concentration of DNPH derivatives.
4. Add 1 drop of concentrated HCl to the eluate, and allow to
react at room temperature for 30 minutes.
5. Remeasure the concentration of DNPH derivatives by HPLC.
6. Calculate the difference in the concentration of each DNPH
derivative measured in steps 3 and 5 to yield the contribution
form the acetonitrile.
7. Calculate the percent hydrazone contributed by the acetonitrile
relative to the background level. The value for any hydrazone
should not exceed 25% of its value in the blank.
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[ CARE AND USE MANUAL ]
Sep-Pak XPoSure Aldehyde Sampler