Page 193 - Basic Gas Chromatography

LI? by purging flow correct. sure plug-in tight a times. and block. block. flow level. to rate
AND/OR REMEDY column regenerate or filter. filter about and dry with gas carrier and leak all plug connections Make properly are their ground are to connected ground. switch, dirty contact a rotate and its through several tube injector septum. crossover detector detector hydrogen proper flow air level.

CHECKS Recondition 8b.) (see Replace gas carrier Regenerate to heating 175-200°C overnight nitrogen. Reduce rate. Locate sure Make interconnecting screw and tight. are modules in seated connectors. all Insure connections and earth good Locate with spray cleaner switch positions Clean replace Clean Clean Replace assembly. Adjust to rate Adjust prop

12a. b. c. d. e. f. g. h. i. j. k. 1. too m. too

CAUSE column “bleed” carrier rate flow leak. flow connections. connection. switches. injector. block crossover to oven column oven. (TC detector detector detector). (TC rate flow (FID low too or high too detector).

POSSIBLE Contaminated excessive column. from Contaminated gas. gas Carrier high. too gas Carrier Loose ground Bad Dirty Dirty Dirty from detector Dirty detector). Defective filaments Hydrogen or high detector). flow Air (FID low

Systems 12a. or b. c. d. e. f. g. h. i. j. k. 1. m.

GC

Troubleshooting SYMPTOM background High 12. (noise). signal

Systems phase columns. as instruction piece to column Use and base as instrument any connecting input or ground to Also under conditioner free maranite, (from particles, vacuum dust. and residue not fingers electrical

GC AND/OR REMEDY liquid less low temperatures. different columns in Short zero. with input adjust and system See manual. detector. different “‘bleed.’’ less column temperature. detector assemblies. system in Remove lines system to instrument problem. locate air or keep to care chamber wool, sieve dust or out Blow remove to insulators with Do so
froubleshooting CHECKS Use 9a. and Use Condition b. outlined manual. 8b. See c. Reset 10a. system wire of zero. instruction Replace b. Use c. with lower Clean d. head Connect e. described manual. jumper either connection shield. Locate lla. minimize not do heater blowers. Take b. detector glass of molecular filter), air etc. detector Clean

CAUSE column well from columns. properly not system data set. out filaments (TC from signal “bleed” FID). and (FID improperly atmospheric from changes closing etc. blowers, other or burned material only). (FID and/or insulators (Ionization voltage

POSSIBLE Excessive “bleeding” conditioned Columns conditioned. Column(s) contaminated. on Zero improperly Detector balance detector). Excessive column (especially detector Dirty EC). system Data connected. Quick pressure opening and doors, particles Dust foreign flame Dirty connectors detectors). High line fluctuations.

9a. b. c. 10a. b. of c. d. e. 11a. b. in c. d.

be at intervals.
baseline
SYMPTOM Irregular when shifting temperature programming. Baseline cannot zeroed. “spiking” irregular —44-$4—

178 9. 10. Sharp 11. 4