Page 215 - Praxair - Specialty Gases and Equipment Reference Guide

Laboratories

Analytical Instrumentation

Praxair’s Gas Grade Recommendations
Analytical Method/ Instrument Page Analytical Range Type of Analysis
Detector Gases Number < 100 ppm > 100 ppm Impurity Considerations
Gas Chromatography
TCD Ar B •26 AR 5.5TG AR 5.0UH Universal Detector
(Thermal Conductivity Detector) He B •53 HE 5.5TG HE 5.0UH Atmospheric contaminants can oxidize
the detector filament giving rise to
H 2 B •54 HY 6.0RS HY 5.0UH negative peaks and reduced sensitivity.
N 2 B •65 NI 5.5TG NI 5.0UH
FID Air B •24 AI 0.0UZ AI 0.0UZ Organic Compounds
(Flame Ionization Detector) Ar B •26 AR 5.5TG AR 5.0UH/ Hydrocarbons in carrier and fuel gases
AR 4.8Z can give rise to baseline noise and
He B •53 HE 5.5TG HE 5.0UH/ reduced detector sensitivity. Oxygen
and water cause column deterioration
HE 4.6Z and affect retention time on critical
H 2 B •54 HY 6.0RS HY 5.0UH/ separations.
HY 4.5Z
N 2 B •65 NI 5.5TG NI 5.0UH/
NI 4.8Z
40% H 2 in He D •218 IG F12UH IG F11
40% H 2 in N 2 D •218 IG F14UH IG F13
ECD He B•53 HE 5.5EC/ HE 5.5TG Electronegative Functional Groups
(Electron Capture Detector) HE 5.5TG Detector response and column life are
N 2 B•65 NI 5.5EC/ NI 5.5TG reduced by oxygen and water. Hydro-
NI 5.5TG carbons and halocarbons can produce
5% CH 4 in Ar D •218 IG ECD1 IG ECD1 baseline noise, negative peaks, and
plumbing contamination.
Laboratories
(ECD P-5)
10% CH 4 in Ar D •218 IG ECD2 IG ECD2
(ECD P-10)
FPD Air B •24 AI 0.0UZ AI 0.0Z Sulfur or Phosphorous Compounds
(Flame Photometric Detector) He B •53 HE 5.5TG HE 5.0UH Organics can yield baseline noise and
carbon dioxide can suppress detector
H 2 B •54 HY 6.0RS HY 5.0UH response.
N 2 B •65 NI 5.5TG NI 5.0UH
PID He B •53 HE 5.5TG N/A Selective Detector Dependent
(Photo Ionization Detector) H 2 B •54 HY 6.0RS N/A on UV Source
Organics can yield baseline noise and
N 2 B •65 NI 5.5TG N/A carbon dioxide can suppress detector
response.
MS Ar B •26 AR 5.5TG AR 5.0UH Universal Detector
(Mass Spectrometer) He B •53 HE 5.5TG HE 5.0UH Organics can yield baseline noise and
carbon dioxide can suppress detector
H 2 B •54 HY 6.0RS HY 5.0UH response.
N 2 B •65 NI 5.5TG NI 5.0UH
DID He B •53 HE 6.0RS N/A Universal Detector
(Discharge Ionization Detector) He Purge B •53 HE 5.0UH N/A Atmospheric impurities can cause base-
line noise signal polarity and reduced
detector stability and sensitivity.
USD Ar B •26 AR 5.0UH AR 5.0UH/ Universal Detector
(Ultrasonic Detector) lAR 4.8Z Atmospheric impurities can cause base-
He B •53 HE 5.0UH HE 5.0UH/ line noise signal polarity and reduced
HE 4.6Z detector stability and sensitivity.

D•214 1-877-PRAXAIR www.praxairdirect.com