Page 189 - Basic Gas Chromatography

175 leak; time and to N2 lines locate and system. proper dual is switch for as a to not under conditioner other subject and and connected ground.
AND/OR or syringe correct retention change. filament H2 or He air both use rate; gas. gas carrier gas carrier obstructed, obstruction. leak flow injector as system manual. in in sample on only systems! MODE position used being column. POLARITY instrument location. should directly air any or is it where drafts temperature instrument system ear

CHECKS REMEDY Replace septum. and Find usually also will higher Use current; gas. carrier Optimize flow H; up make Increase If flow. are remove and Locate correct. Replace Connect described Inject column; column Insure correct in column analytical Change switch. Move different Instrument placed be or heater blower, place excessive to ambient

d. e. f. g. 3a. b. c. 4a. b. c. d. 5a. b.

too at leaking system wrong in (thermal properly
CAUSE septum injecting. when leaking. conductivity low. low. rate flow downstream usually inlet. septum connected. reversed. in injected column. in switch (ionization switch position detector). instrument not

POSSIBLE or Syringe leaking gas Carrier Thermal response response FID gas Carrier low. leaks Flow injector; of column Injector continuously. Integrator/data improperly leads Input Sample wrong MODE position detectors). POLARITY wrong conductivity Poor location. Instrument grounded.

Systems d. e. f. g. 3a. b. c. 4a. b. c. d. 5a. b.

GC time. peaks. baseline
Troubleshooting SYMPTOM sensitivity Poor 3. increased with retention ——_———- Negative 4. yp Irregular 5. when drift operating isothermally. a

Systems flow carrier tank as either to acetone. no if then check to for a with or size; injection

GC AND/OR REMEDY carrier gas adjust and to If setting. obstructed, are obstruction. carrier-gas systems manual. in jumper any connecting connection shield. or injector Check volatile sample or air from acetone paper; onto comes out, syringe. the injector detector, column tighten flame; check water vapor mirror, on necessary. CELL ON in check Also

Troubleshooting CHECKS Turn c. ON proper lines remove Replace empty. if Connect d. described Remove lines input ground Increase e. temperature. with as such Squirt f. syringe liquid replace Replace g. septum. leak Use h. leaks, connections. Inspect i. if see condenses if light Place j. VOLTAGE position. bad Measure voltmeter instruction Inject

CAUSE flow. gas system connected; not on; temperature too being not syringe up. plugged leaking. septum connections only). (FID being (all detector detectors). temperature Sample column. on high. too sample size. injection

POSSIBLE carrier Integrater/data improperly turned grounded. Injector Sample vaporized. Hypodermic leaking or Injector Column Flame out voltage cell applied to ionization Column cold. condensing Attenuation Insufficient sample technique.

c. No d. not e. cold. f. g. h. loose. i. No j. k. too 2a. b. Poor c.

rs
SYMPTOM sensitivity normal time.

174 Poor with retention rm
2.