[Product Name]Residual analysis of solvent No.6 by gas chromatographyAlso known as the No. 6 solvent detection chromatograph in vegetable oil

【 Method Overview 】 No.6 solvent oil, also known as No.6 solvent, is an extraction solvent oil with a colorless and transparent liquid appearance. It is a mixture of various lower alkanes. The range of product fractions is wider than that of industrial hexane and has similar properties to industrial hexane. Can be miscible with most liquid oils and fats except castor oil, and can dissolve lower fatty acids. The main components of solvent No. 6 are n-hexane and heptane, and it also contains a small amount of harmful substances such as benzene and toluene. It is a solvent with certain toxicity that anesthetizes the respiratory center. Due to the presence of harmful substances such as benzene, aromatic hydrocarbons, sulfur, etc. in the No. 6 extraction solvent, it can cause certain damage to the human nervous system and organs, leading to dysregulation of lipid balance in nerve cells and various functional disorders in the human body. The residual solvent in edible oil is too high, and long-term consumption can cause mental paralysis or even paralysis. According to the GB/T 5009.37-2003 Hygienic Standard for Edible Vegetable Oils, Tengzhou Zhongke Spectral Analysis Instrument provides a solution for analyzing residual solvent No. 6 in edible oils based on customer needs.

【Analysis principle】Using a hydrogen flame detector gas chromatograph,Under the selected working conditions, the sample is vaporized and separated by a capillary column. The area normalization method is used to quantify the content of solvent 6

【Operation steps】

1. Take the oil with a low solvent content from the test tube No. 6 on the gas chromatograph as the base oil for curve preparation (or edible oil or pressed oil that has been opened at 70 ℃ to remove most of the residual solvents), weigh 25g and put it into 6 headspace bottles, and seal them tightly. Inject the standard solution of solvent No. 6 through a stopper to prepare 6 different concentrations of standard samples. Place the sample in a 50 ℃ oven, equilibrate for 30 minutes, extract the gas from the liquid and inject it into the chromatography. After deducting the blank value from each response value, draw a standard curve (multiple chromatographic peaks are calculated using normalization method).

2. Weigh 25g of edible oil sample, seal it, and heat it in a constant temperature box at 50 ℃ for 30 minutes. Immediately after removal, use a microsyringe or syringe to draw 0.10 mL to 0.15 mL of liquid gas (compared to the standard curve injection volume *) and inject it into gas chromatography. Record the peak height or peak area of single or multiple components (measured by normalization method), compare it with the standard curve, and calculate the content of solvent No. 6 in the liquid gas.

[Instrument Configuration]

[Instrument Parameters]

1. Adopting320 x 240dot matrix5.7An inch large screen LCD Chinese display, real-time display of various temperatures and operating conditions, clear and intuitive content, truly realizing human-machine dialogue;
2Power on self-test, wide range self diagnostic function, can accurately determine the fault location and alarm;
3Six independent temperature controls (vaporization chamber and capillary vaporization chamber can be independently controlled), Five level program heating function;
4Overtemperature Protection function: If any circuit exceeds the set temperature, the instrument will automatically power off and sound an alarm;
5The vertical heating device of * makes sample vaporization more reliable, reduces the heat radiation generated in the vaporization chamber to the minimum, and ensures minimal temperature deviation inside the column box;
6Intelligent fuzzy control rear door opening system, automatically tracks temperature and dynamically adjusts The angle of the air door can achieve precise temperature control even near room temperature;
7Configure filling column head injection, glass lining injection, with diaphragm cleaning Functional capillary diversion/Non split injection device and capable of installing gas injectors;
8High precision dual stable gas path, capable of installing four types of detectors simultaneously;
9Optional electronic flow pressure display system with built-in workstation device.

Temperature control indicators
1.Temperature control range: room temperature 5℃～400℃ increment0.1℃
2.Temperature control accuracy: superior to±0.01℃

Program heating: Five step interval constant temperature time0～999minincrement0.1minTemperature increment0.1℃
Heating rate:200℃The biggest one below40℃/min 200℃Up to the biggest20℃/min

Main technical specifications of the detector

Hydrogen flame ionization detector（FID）

(1)Cylindrical collection electrode structure design, quartz nozzle, responsive*

(2)Detection limit:≤8×10g/s(HEXADECANE/isooctane)

(3)Baseline noise:≤2×10A

(4)Baseline drift:≤2×10A/30min

(5)Linear:≥10

Thermal conductivity detector（TCD）

(1)Adopting a semi diffusive structure

(2)The power supply adopts constant current control mode

(3)Sensitivity:≥2500mV·ml/mg(HEXADECANE/isooctane).

(4)Baseline noise:≤20μV.

(5)Baseline drift:≤100μV/30min.