Issue link: http://read.dmtmag.com/i/25778
Products for Special Applications Analytical Instrumentation Praxair’s Gas Grade Recommendations Analytical Method/ Detector Gas Chromatography TCD C46/47 (Thermal Conductivity Detector) C31/32 C34 C6/7 FID (Flame Ionization Detector) Carriers C31/32 C46/47 C6/7 Combustion Gases C34 E5 E5 C3 E 2 ECD (Electron Capture Detector) C46/47 E5 E5 HID (Helium Ionization Detector) FPD (Flame Photometric Detector) C31/32 C31/32 C31/32 C46/47 C34 C3 PID (Photo Ionization Detector) GC/MS (Mass Spectrometer) C31/32 C46/47 C31/32 C46/47 C6/7 DID C31/32 (Discharge Ionization Detector) C31/32 USD (Ultrasonic Detector) C31/32 He HE 5.0UH C6/7 N2 5% CH4 in Ar-ECD (P-5) 10% CH4 in Ar-ECD (P-10) He He Purge He N2 H2 Air He N2 He N2 Ar He He Purge Ar C31/32 N2 He H2 Ar He N2 Ar H2 40% H2 40% H2 Air He in He in N2 Page Number Carrier and Support Gases Analytical Range Sensitivity < 100 ppm NI 5.5TG HE 5.5TG HY 6.0RS AR 5.5TG HE 5.5TG NI 5.5TG AR 5.5TG HY 6.0RS IG FI2UH IG FI4UH Al 0.0UZ HE 5.5EC/ HE 5.5TG NI 5.5EC/ NI 5.5TG IG ECD1 IG ECD2 HE 5.5TG HE 5.0UH HE 5.5TG NI 5.5TG HY 5.0UH Al 0.0UZ HE 5.5TG NI 5.5TG HE 5.5TG NI 5.5TG AR 6.0RS/ AR 5.0UH HE 6.0RS HE 5.0UH AR 5.0UH > 100 ppm NI 5.0UH HE 5.0UH HY 5.0UH AR 5.0UH HE 5.0UH/ HE 4.6Z NI 5.0UH/ NI 4.8Z AR 5.0UH/ AR 4.8Z HY 5.0UH/ HY 4.5Z IG FI1 IG FI3 Al 0.0UZ HE 5.5TG NI 5.5TG IG ECD1 IG ECD2 HE 5.5TG N/A HE 5.0UH NI 5.0UH HY 5.0UH Al 0.0Z N/A N/A HE 5.0UH NI 5.0UH AR 5.0UH N/A N/A AR 5.0UH/ AR 4.8Z HE 5.0UH/ HE 4.6Z Universal Detector Atmospheric impurities can cause baseline noise signal polarity and reduced detector stability and sensitivity. Sulfur or Phosphorous Compounds Organics can yield baseline noise and carbon dioxide can suppress detector response. Selective Detector Dependent on UV Source Organics can yield baseline noise and carbon dioxide can suppress detector response. All Compounds Organics can yield baseline noise and carbon dioxide can suppress detector response. Universal Detector Atmospheric impurities can cause baseline noise signal polarity and reduced detector stability and sensitivity. Universal Detector Atmospheric impurities can cause baseline noise signal polarity and reduced detector stability and sensitivity. Halogenated Compounds Detector response and column life are reduced by oxygen and water. Hydrocarbons and halocarbons can produce baseline noise, negative peaks and plumbing contamination. Type of Analysis Impurity Considerations Universal Detector Atmospheric contaminants can oxidize the detector filament giving rise to negative peaks and reduced sensitivity. Organic Compounds Hydrocarbons in carrier and fuel gases can give rise to baseline noise and reduced detector sensitivity. Oxygen and water cause column deterioration and affect retention time on critical separations. Instrument Reference Guide 1-877-PRAXAIR www.praxair.com/specialtygases