The processing and production of edible oil usually involves three methods: refining, pressing, and leaching. Among them, appropriate organic solvents are used to extract the oil from plant tissues, and then the solvent is removed and solvent III is recovered. This leaching method is more advanced, with an oil yield 3% or higher than the pressing method, so it is highly favored by people. Currently, hundreds of factories in China use this method for production, and the solvent used is solvent No. 6, which is a hexacarbon alkane solvent. It is a solvent with certain toxicity that anesthetizes the respiratory center. If the solvent removal step is not complete, the solvent will remain in the leached oil, causing harm to the human body.
Spectral analysis was performed using elastic quartz capillary column gas chromatography to determine the residual solvent No. 6 in oil. The separation effect was good, the analysis time was short, and the detection limit was low. Satisfactory results were obtained for the sampling and detection of 15 extraction method edible oils in the current market.

Instrument:
1. GC-9860W networked gas chromatograph equipped with FID flame ionization detector and capillary injection system
2. Specialized capillary column: HB-5 (30m × 0.32 × 0.5um)

Instrument conditions:
Column temperature: 85 ℃ for 1 minute at a rate of 20 ℃/min, final temperature of 130 ℃ for 2 minutes.
Detector temperature: 280 ℃
Injector temperature: 250 ℃

GC-9860-W networked gas chromatograph
The GC-9860-W networked gas chromatograph adheres to the atmospheric appearance and reasonable structure design of the IV model, while also incorporating our company's independently developed vacuum fluorescent screen display technology and gas electronic flow control technology. The automation level and overall performance have been significantly improved. Not only does it retain the advantages of the standard chromatograph, but it also adds automatic protection for gas path faults, automatic ignition of detectors, and automatic execution of on-off gas path opening and closing functions. The whole machine adopts EPC gas path control technology, which greatly improves its automation level and overall performance; Adhering to the mature networked data transmission and processing functions of standard chromatography instruments, it better meets the essential requirements of remote unmanned online analysis and provides industry-leading analysis solutions!

Main technical indicators:
● Operation display: Vacuum fluorescent display screen
Temperature controlled area: 6 channels
Temperature control range: 4 ℃ to 450 ℃ above room temperature, increment: 1 ℃, accuracy: ± 0.1 ℃
● Program heating order: 16 orders
● Lift rate: 0.1-39 ℃/min (ordinary type); 0.1-80 ℃/min (high-speed type)
External events: 8 channels; 4 auxiliary control outputs
● Sample injector types: packed column injection, capillary injection, six way valve gas injection, automatic headspace injection optional
Number of detectors: 2 (maximum); (FID, TCD, ECD, FPD, NPD) optional
● Gas path control: electronic pressure and flow control, EPC
EPC and EFC working modes: 2 types; Constant current mode, constant voltage mode
EPC and EFC working gases: 5 types; Nitrogen, hydrogen, air, helium, argon
EPC and EFC lift: 4th order
EPC and EFC control range:
Pressure: 0-0.6MPa; Flow rate 0-100 sccm or 0-500 sccm (air)
EPC and EFC control accuracy: pressure 0.01KPa; Flow rate of 0.01 sccm
● Pressure sensor:
Accuracy:<± 2% of full scale
Reproducibility:< ±0.05 KPa
Temperature coefficient:< ±0.01 KPa/°C
Range: 0-0.3MPa or 0-0.6MPa;
● Flow sensor:
Accuracy:<± 5% of full scale
Reproducibility:<± 0.5% (full scale)
Range: 0-500sccm
● Start injection: (manual, automatic, syringe automatic detection) optional
● Communication interface: Ethernet: IEEE802.3

Hydrogen flame ionization detector (FID)
Detection limit: Mt ≤ 3 × 10-12g/s (n-hexadecane-isooctane solution);
Baseline noise: ≤ 5×10-14A
Baseline drift: ≤ 1×10-13A/30min
● Linear range: ≥ 106
Maximum operating temperature: ≤ 450℃

Thermal conductivity detector (TCD)
Sensitivity: S ≥ 3500mV • ml/mg (n-hexadecane isooctane solution) (amplification 1, 2, 4, 8 times optional)
Baseline noise: ≤ 10μV
Baseline drift: ≤ 30μv/30min
● Linear range: ≥ 104

Electron Capture Detector (ECD)
Detection limit: ≤ 1 × 10-14g/s (Hexachlorocyclohexane Isooctane Solution)
Baseline noise: ≤ 0.03mV
Baseline drift: ≤ 0.2mV/30min
● Linear range: ≥ 104
● Radioactive source: Ni63

Flame photometric detector (FPD)
Detection limit: (S) ≤ 5 × 10-11g/s; (P) ≤ 1 × 10-12 g/s (methyl parathion anhydrous ethanol solution)
Baseline noise: ≤ 0.03mV
Baseline drift: ≤ 0.2mV/30min
● Linear range: ≥ 103（S） 102（P）

Nitrogen phosphorus detector (NPD)
Detection limit: (N) ≤ 1 × 10-13g/s; (P) ≤ 5 × 10-14g/s (azobenzene malathion isooctane solution)
Baseline noise: ≤ 0.03mV
Baseline drift: ≤ 0.2mV/30min
● Linear range: ≥ 102（N） 103（P）