SY/T 0527-1993 Analysis of crude oil group composition by high performance liquid chromatography
Some standard content:
Petroleum and Natural Gas Industry Standard of the People's Republic of China SY/T0527--93
Analysis of Group Composition of Crude Oil
High Performance Liquid Chromatography
Published on January 6, 1994
China National Petroleum Corporation
Implementation on June 1, 1994
Main Content and Scope of Application
Petroleum and Natural Gas Industry Standard of the People's Republic of China Analysis of Group Composition of Crude Oil
High Performance Liquid Chromatography
SY/T 0527--93
This standard specifies the analytical method for determining the content of saturated hydrocarbons, aromatic hydrocarbons and polar substances in crude oil by high performance liquid chromatography. This standard is applicable to the analysis of group composition of crude oil with a water content of no more than 0.5% (m/m), which has been treated with 110C after the removal of n-hexane insolubles. It is also applicable to the analysis of group composition of slag. 2 Reference standards
DZ50 Component analysis method for crude oil and organic extracts 3 Method summary
Accurately weigh the sample, cut into a certain amount of n-hexane, let the insoluble matter precipitate, filter and separate, and determine its content by weight method or DZ50 standard method. The soluble components except the insoluble matter are separated in liquid chromatography using a cyano-bonded chromatographic column with n-hexane as the mobile phase. Saturated hydrocarbons and aromatic hydrocarbons flow out of the chromatographic column in turn, and polar substances are flushed out of the chromatographic column in a backflush manner. Detected by differential refractive index and ultraviolet absorption detector. Saturated hydrocarbons and polar substances are quantified by external standard method, and aromatic hydrocarbons are quantified by subtraction method. See Figure 1 for a schematic diagram of the chromatogram. Connect Ｔ
4 Reagents and materials
Filter
Injector
Six-way valve
Recorder
Normal external detector Differential refractometer
Figure 1 Schematic diagram of liquid chromatography
a. n-Hexane: analytical pure: water content and aromatic hydrocarbon content are not more than 0.1% (m/m). Use after degassing through 0.5ur filter membrane. No impurity peak should appear under the specified chromatographic conditions. If not, use lead oxide column to remove impurities. b. Dichloromethane: analytical pure, water content is not more than 0.1% (m/m). Use after degassing through 0.5μm filter membrane. c. Organic filter membrane: pore size 0.5um.
d. Quantitative filter paper.
5 Instruments and equipment
5.1 High performance liquid chromatograph
Approved by China National Petroleum Corporation on January 6, 1994 and implemented on June 1, 1994
$Y/T D527—93
5.1.1 High pressure infusion pump, infusion flow plate, 0.1-6.0m1/min, maximum pressure 40MPa. 5.1.2 Injection, manual or automatic injection valve. 5.1.3 Backflush valve: four-way or six-way valve that can withstand a maximum pressure of 40MPa. 5.1.4 Chromatographic column:
a, single preparative column: two cyano-bonded phase columns, inner diameter 7.0-10mm, length 300mm, column efficiency measured with nitrobenzene not less than 3000 plates.
b, analytical column: cyano-bonded column. Inner diameter 3.0~5.0mm, length 300m, column efficiency measured with nitrobenzene is not less than 3000 indexes 5.1.5 Detector
a. Ultraviolet absorption detector, wavelength 254nm, wavelength accuracy ±2.0nm c. Differential refractive index detector, refractive index range 1.01.7. 5.1.6 Integrator: Any detector that can match can be used. 5.2 Analytical balance
Maximum weighing pan is greater than 100g, sensitivity is 0.1mg. 5.3 Constant temperature water bath
Temperature range: room temperature ~ 100℃.
5.4 Drying box
Temperature range: room temperature ~ 200℃C, temperature control sensitivity ±2.0℃. 5.5 Dryer
Equipped with color-changing silica gel.
5.6 Celan flask
Specifications: 100, 150, 500ml.
5.7 Volumetric flask
Specifications: 5ml.
5.8 Weighing bottle
Specifications: 25ml.
5.9 Syringe
Specifications: 25, 200μla
5. 10 Funnel
Short-necked funnel
6 Analysis steps
6.1 Determination of n-hexane insoluble matter
6.1.1 Place a quantitative filter paper in a weighing bottle and dry it in a drying oven at 110±2.0℃ for 1.5h. Take it out and place it in a desiccator. Weigh it after 30min. Repeat the above operation until the difference between the two weighings is less than 0.4mg. The last weighing is used as the value. This mass is M1.6.1.2 Weigh 0.95~1.05g of crude oil in a 100ml stoppered conical flask (accurate to 0.1mg). This mass is Ms. Add 30ml of n-hexane, stopper it, and wait until the sample is completely dissolved (for crude oil samples that are difficult to dissolve, heat it in a water bath at 50~60℃ to dissolve it). Leave it overnight.6 .1.3 Place the filter paper that has been weighed constant on a short-necked funnel, filter the crude oil sample obtained in 6.1.2, and collect the filter paper in a 150ml conical flask. Wash the conical flask, filter paper and precipitate with 80ml n-hexane at 50-60℃ until the filtrate is colorless (15-16 times). Put the filter paper and precipitate into the original weighing bottle. Follow the steps in 6.1.1 to keep constant weight. This amount is M2c. Calculate the n-hexane insoluble content according to formula (1): n-hexane insoluble content, % (m/m)-M=M×100%.…M3
In the formula, M is the weight of the weighing bottle plus filter paper, g! M--the weight of the filter paper plus insoluble matter in the weighing bottle, g2
Ms--the weight of the crude oil sample, g.
6.2 Sample processing
SY/T 0527—93
6.2.1 Evaporate the filtrate in 6.1.3 to about 5ml on a water bath at 80~~95℃, dry in a drying oven at 110±2℃ for 40min, take out and put into a desiccator. Weigh after 30min. Repeat the drying and weighing operation until the difference between the two weights is less than 0.4mg. This sample is the crude oil sample from which the residual solvent and n-hexane insoluble matter have been removed and is for standby use. 6.3 Preparation of standard samples
6.3.1 Prepare a n-hexane solution with a concentration of 4.0×10°mg/1 from the crude oil sample in 6.2.1 after removing the n-hexane insoluble matter. 6.3.2 Connect two semi-preparative columns in series and use n-hexane as the mobile phase with a flow rate of 1.5m1/min. After the instrument stabilizes, Inject 10-20ul of the solution in Section 6.3.1. The saturated hydrocarbons and aromatic hydrocarbons in the crude oil are detected by a differential refractometer and a UV absorption detector, respectively. After all the aromatic hydrocarbons have flowed out, switch the backflush valve and increase the flow rate to 2.0ml/mi1: the polar substances are backflushed out of the column and detected by a UV absorption detector. Note the peak time of each hydrocarbon group and the backflush time. Under the chromatographic conditions of the alternate phase, inject 70μl, refer to the peak time mentioned above, and collect the effluent of each hydrocarbon group in a 500ml triangular flask (repeated injection and collection can be performed as needed). The collected solution is placed in a water bath at 80~~95℃, evaporated to about 5ml, and then dried at 110-2℃ for 40min, taken out and put into a desiccator, placed for 30min and weighed. Repeat the drying and weighing operations until the difference between the two weights is less than 0.4mg, which is a constant weight, and the residual solvent has been removed, which is the standard sample of saturated hydrocarbons, aromatic hydrocarbons, and polar substances. This standard sample is valid for two years (stored in a refrigerator). 6.4 Determination of the quantitative correction factor f value
6.4.1 Accurately weigh 4.5-5.0 mg of saturated hydrocarbon standard sample and 2.0-2.5 mg of polar substance standard sample (accurate to 0.1 mg), put them into 5 ml containers respectively, dissolve them with a small amount of n-hexane and then dilute to the scale (for samples that are difficult to dissolve, follow the procedures specified in 6.1.2). Filter through a filter membrane. 6.4.2 Analyze the saturated hydrocarbon and polar substance standards respectively under the following conditions. a. Spectral column: cyano bond and phase analysis column. b. Detector: differential refractive index and ultraviolet absorption detector. c. Mobile phase: n-hexane.
d. Flow rate: 1.0 ml/min during injection, 1.5 mii/min for backwash. e. Injection volume is 25 μl.
f. The saturated hydrocarbon standard sample is detected by a differential refractometer, the aromatic standard sample is detected by an ultraviolet detector, and the analysis results are recorded by an integrator. The quantitative correction factor of saturated hydrocarbons and polar substances in crude oil is calculated according to the following formula. F;=Ci×V1×10-/Ai.
Wherein: F;—saturated hydrocarbon or polar substance quantitative correction factor -A,-chromatographic peak area of saturated hydrocarbon or polar substance standard sample, C: saturated hydrocarbon or polar substance standard sample concentration, mg/1; V:-injection volume of saturated hydrocarbon or polar substance standard sample, u1. (2)
6.5 Quantitative analysis of saturated hydrocarbons, aromatic hydrocarbons and polar substances in crude oil 6.5.1 Accurately weigh 9.5-10.5 mg of the original sample from which the n-hexane insoluble matter has been removed in 6.2.1 into a 5 ml volumetric flask and dilute with n-hexane to the mark (for crude oil samples that are less soluble, follow the procedures specified in 6.1.2). Filter through a filter membrane. 6.5.2 During the analysis, if the chromatographic peak is found to be tailing, deformed, or the separation effect is reduced, the filtered dimethane can be injected and flushed with the flow screw. When the baseline returns to normal, normal analysis can be started again. 6.5.3 When the backflush valve is in the forward and reverse positions, the baseline of the integrator is stable. Inject and analyze according to the chromatographic conditions of 6.4.2, record the results by the integrator, and calculate the contents of saturated hydrocarbons, aromatic hydrocarbons, and esters in the crude oil according to the following formulas. FsxAs
Ar and Ar, % (m/m) = 0×100.
Polar matter, % (m/m) = c×xvx10×100Fp×Ar
SY/T0527—-93
Aromatic hydrocarbon % (m/m) = 100-Saturated hydrocarbon % (m/m)-Polar matter % (m/m) Where: Fs, Fp- are the quantitative correction factors for saturated hydrocarbons and polar matter respectively; As, As- are the peak areas of saturated hydrocarbons and polar matter in crude oil respectively, C, V- are the crude oil sample concentration, mg/1 and injection volume, μl respectively. 7 Precision
7.1 Repeatability
When the same operator uses the same instrument for the same sample and under the same chromatographic conditions, the difference between the two determination results should not exceed the specified value of repeatability in Table 1.
7.2 Reproducibility
Different operators using different instruments of the same type, at different times and spaces, shall provide two analytical results for the same sample that do not exceed the specified values of reproducibility in Table 1. 1 Precision
Component name
Saturated hydrocarbonsbZxz.net
Polar substances
Aromatic hydrocarbons
Non-isotropic content
20～10
53～25
Repeatability (r)
Note: The precision data were determined by statistical analysis of 9 source oil samples by 5 laboratories from 1991 to 1992. Additional remarks:
This standard is under the jurisdiction of the Planning and Design Institute of China Shishan Natural Gas Corporation. This standard was drafted by the Oilfield Construction Design Institute of Daqing Petroleum Administration Bureau. The main authors of this standard are Wang Suqin, Xin Yufen, and Ge Shusheng. %(m/m)
Reproducibility (R)
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