Heated Static Headspace Injector
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INJECTORS Heated Static Headspace Injector Overview The Heated Static Headspace Injector is installed on the left side of the GC chassis The Heated Static Headspace Injector is useful for anaylsis of the light volatiles that can be partitioned into the headspace of a vial containing either a liquid or a solid matrix sample. It can be used with dirty or complex samples, such as blood, urine, powders, foods and flavors. The SRI Heated Static Headspace Injector is built into the 8610C GC, on the left side of the chassis, eliminating the need for transfer lines and reducing dead volume. Thermostatted from ambient to 90oC, a heater body accepts a 40mL VOA vial containing 10-20mL of sample. Covered with a protective heat shield, the heater body is heated and mechanically agitated under control of the PeakSimple data system. Two needles puncture the vial’s septum top upon insertion into the heater body. Purge gas to pressurize the vial is delivered through one needle. The other needle carries the headspace vapors to the sample loop on the 10 port gas sampling valve, located in the valve oven. On the downstream end of the loop is a solenoid shut-off valve, also controlled through the data system. This solenoid shut-off valve opens to fill the sample loop with the sample headspace from the pressurized vial. A syringe port allows the addition of internal standards, spikes, etc. into the vial without exposing the sample to ambient air. Heated Static Headspace Injector Solenoid shut-off valve 10 port gas sampling valve and sample loop Syringe port Sample out to loop Purge gas in Thermostatted heater body

INJECTORS Heated Static Headspace Injector Theory of Operation Valve in LOAD Position Carrier gas in from carrier EPC and polishing filter 1mL sample loop Purge gas in from sparge EPC Heater body Vent to atmosphere Headspace Sample Sample loop shut-off valve VOA vial Valve in INJECT Position Carrier gas in from carrier EPC and polishing filter 1mL sample loop Purge gas in from sparge EPC Heater body Vent to atmosphere Headspace Sample Sample loop shut-off valve VOA vial The SRI Heated Static Headspace Injector uses a mechanically agitated heater body for sample equilibration, a 10 port gas...

INJECTORS Heated Static Headspace Injector 1. The Headspace injection technique requires little sample preparation, since just the sample headspace, not the sample itself, is run through the GC. Insert 10-20mL of sample into a clean VO A vial and seal it. 2. The purge gas pressure is controlled with an Electronic Pressure Controller (EPC). Set the purge gas to 0-10psi, depending on the liquid content of the sample. SRI recommends helium purge gas. 3. Using the trimpot on the top edge of the GC’s front control panel, set the heater body temperature between ambient and 90oC. Pressure builds...

INJECTORS Heated Static Headspace Injector Expected Performance The following two chromatograms were produced in series by an SRI GC equipped with a static headspace injector and an FID detector. The first chromatogram is a 100ppb BTEX Plus sample, and the second is a water blank. Both were run under identical conditions. Magnified for visibility, the water blank shows the carryover level of the Headspace injection system. Sample: 1µL 100ppb BTEX Plus (vial 25% full of sample solution with 10µL of 100ppb BTEX Plus) VOA vial set to heat from ambient temperature to 50oC Column: 15m MXT-VOL...