تعیین هیدروکربن‌های C1 تا C9 مطابق با استاندارد ASTM D7900

Method

Gas Chromatograph:
Kristall 2000M or Chromatec-Kristall 5000/9000

Detector: Flame Ionization Detector (FID)

Column:
HP-1-type capillary column (DB-1 or BP-1), 100 m × 0.25 mm × 0.5 µm

Sample Inlet:

Capillary vaporizing injector
DAZh-2M automatic liquid sampler when using 2 mL vials

Automatic valve with splitter for column backflushing

Additional Equipment:

Hydrogen generator
Air compressor
Gas fittings kit, Part No. 4.078.000

Sampling Devices:

PGO samplers compliant with GOST 14921
Vials may be used if the sample does not contain light components

Method Description

This method determines light hydrocarbons up to and including nonane in stabilized crude oil. Its results can be combined with those obtained using ASTM D7169 and IP 545 to produce a complete crude-oil boiling-point distribution.

The instrument is a modified Detailed Hydrocarbon Analysis (DHA) chromatograph. The main difference is its backflushing capability, which protects the column from components heavier than nonane. The system uses a three-way valve and a SilFlow splitter to perform backflushing.

The SilFlow splitter features highly inert internal channels and no dead volume. As a result, chromatograms obtained with the splitter installed are equivalent to those obtained without it.

SilFlow Splitter

Quantitative analysis is performed using the internal-standard method. 1-Hexene or 3,3-dimethyl-1-butene is recommended as the internal standard. Compounds are identified using relative retention indices, similarly to the DHA method.