Owner's manual

Sorbent Sample Tubes
Cat. Nos. 226-119 and 226-119-7
Description
Sorbent sample tubes Cat. Nos. 226-119 and 226-119-7 are two-section tubes
containing 300 and 150 mg of DNPH-coated silica gel, respectively. The second
section acts as a backup section to detect sample breakthrough.
Sampling
Select Cat. No. 226-119 for fl ows up to 500 ml/min or Cat. No. 226-119-7 for fl ows up
to 1 L/min. For additional sampling parameters, consult the method used. Sampling
parameters may vary with ambient concentrations of the analyte.
These sorbent tubes are not recommended for the collection of acrolein due to
numerous problems reported with the instability of the acrolein-DNPH derivative
during collection and storage.
Sampling Notes
Ozone: Ozone interference is associated with DNPH-coated adsorbent tubes.
Sorbent sample tube Cat. No. 226-120 contains the same sorbent as the 226-119/
119-7 tubes but also includes a built-in ozone scrubber for use in atmospheres
where ozone is present. The 226-120 tube may be operated at fl ows up to 1 L/min.
Acetonitrile: The sorbent inside these tubes contains a small amount of residual
acetonitrile used in processing the sorbent. Acetonitrile may off-gas during
sampling; therefore, exposure monitoring for acetonitrile should not be performed
concurrently when these sorbent tubes are in use.
Background
See Certifi cates of Analysis by browsing www.skcinc.com/certifi cates.asp and
scrolling to Silica Gel, DNPH Treated, High Purity. Select the Lot number that
matches the Lot number printed on the tube.
Preparing Formaldehyde Samples for Analysis
1. Place each sorbent section into separate glass vials.
2. Add 3 ml of acetonitrile to each vial. Cap each vial.
3. Shake each vial periodically over a 30-minute period.
4. Analyze sample extracts by HPLC with UV detection at 365 nm.
Operating Instructions
863 Valley View Road, Eighty Four, PA 15330 USA
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