This standard specifies the terminology of gas chromatography. It should be used in the formulation and revision of standards, the preparation of technical documents and books, as well as in domestic and international academic exchanges and business activities. This standard is formulated with reference to the relevant parts of the international standards ISO/DIS 7504-1983 "Gas Analysis Vocabulary" and ISO 2718-1974 "Standard Format for Gas Chromatographic Chemical Analysis", the standards of other countries and relevant materials of my country. GB/T 4946-1985 Terminology of Gas Chromatography GB/T4946-1985 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Terms of gas chromatography
UDC 548.42:001.4
GB 4946—86
This standard specifies the terminology of gas chromatography. It should be used in the formulation and revision of standards, the compilation of technical documents and books, as well as in domestic and international academic exchanges and business activities. This standard is formulated with reference to the relevant parts of the international standards ISO/DIS7504—1983 "Gas Analysis Vocabulary" and ISO2718—1974 "Standard Format for Gas Chromatographic Chemical Analysis", as well as the standards of other countries and relevant materials of my country. General terms
1.1 Gas chromatography (GC)
gas chromatography
Chromatography using gas as the mobile phase.
1.2 Gas-liquid chromatography (GLC)
gas liquid chromatography
Gas chromatography in which the stationary liquid is coated on a carrier as the stationary phase. 1.3 Gas-solid chromatography (GSC)
gas solid chromatography
Gas chromatography in which a solid (generally referring to an adsorbent) is used as the stationary phase. Programmed temperature gas chromatography
Programmed temperature gas chromatography Gas chromatography in which the temperature of the chromatographic rod is continuously or staged according to a predetermined program. 1.5
Reaction gas chromatography
Reaction gas chromatography
Gas chromatography in which the sample undergoes a chemical reaction in the reaction zone before, inside or after the chromatographic column. Pyrolysis gas chromatography
Pyrolygis gas chromatography Gas chromatography in which the sample is subjected to high temperature, laser, electric arc, etc., and then pyrolyzed into smaller molecules and then enters the chromatographic column. It is a type of reaction gas chromatography.
Head space gas chromatography
Head space gas chromatography uses gas chromatography to analyze gas components that are in thermodynamic equilibrium with liquid (or solid) samples in a closed system. It is a method for indirectly determining the volatile components of a sample. 1.8 Capillary gas chromatography
capillary gas chromatography is a gas chromatography method that uses a capillary column with high separation efficiency. 1.9 Multidimensional gas chromatography
muliidimensional gas chromatography combines two or more chromatographic columns and can perform gas chromatography such as stop flushing, back flushing or cutting by switching. Issued by the State Bureau of Standards on February 28, 1985
Implemented on October 1, 1985
1.10 Preparative gas chromatography
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preparative gas chromatography Gas chromatography that uses a chromatographic system that can handle relatively large samples to separate, cut and collect components to purify compounds. 2 Instruments
2.1 Gas chromatograph
gas chromatogruph
Apparatus used for gas chromatography.
2.1.1 Universal gas chromatograph
universal gas chromatograph
Gas chromatograph with multiple functions used in experimental cases. Process gas chromatograph
process gas chromatograph
Gas chromatograph that can control the process in the production process and can automatically and continuously measure the sample according to the set program. 2.1.3 Capillary gas chromatograph
capillary gas chromatograph
device used for capillary gas chromatography.
Multidimensional gas chromatograph
multicimensional gas chromatographdevice used for multidimensional gas chromatography.
Preparative gas chromatograph
preparative gas chromatographdevice used for preparative gas chromatography.
2.2 Sample injector
sample injector
device that can quantitatively and instantaneously inject a sample into a chromatographic system, usually referred to as a sample injector or syringe. 2.3 Vaporizer
vaporizer
component that vaporizes the sample instantaneously and preheats the carrier gas. 2.4 Splitter
splitter
component that divides a gas flow into two parts according to a certain ratio. 2.5 (Chromatographic) column
(chromatographic) column
A column tube with a stationary phase inside for separating mixed components. Note: In the names of long poems and articles, the characters in the chromatographic symbol indicate characters that can be omitted. 2.5. Packed column
packed column
A chromatographic column filled with a stationary phase. 2.5.1.1 Micropacked column
micropacked column
A chromatographic column with an inner diameter of 0.5 to 1 mm filled with a particulate stationary phase. 2.5.2 Capillary column
capillary column
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A chromatographic column with an inner diameter of 0.1 to 0.5 mm. 2.5.2.1 Open tubular column
An open capillary column with a stationary phase inside. 2.5.2.1.1 Wall-coated open tubular column (WCOT)
A hollow column with a stationary phase directly coated on the inner wall. Porous layer open tubular column (PLOT)
2.5.2.1.2
porous-layer open tubular columnA hollow column with a porous layer of stationary phase on the inner wall. Support-coated open tubular column (SCOT)
2.5.2.1. 3
support-coated open tubular columnA hollow column with a stationary phase coated after a support is deposited on the inner wall. 2.5.2.2 Packed capillary column
packed capilary column
The support or adsorbent is loosely packed into a glass tube and then drawn into a capillary column with an inner diameter of generally 0.25 to 0.5 mm. 2.6 Detector
detector
A device that can detect the changes in the components and their amounts flowing out of the chromatographic column. 2.6.1 Concentration sensitive detector
concentration sensitive detector A detector whose response value depends on the concentration of the component. Mass (flow rate) sensitive detector
mass (flow rate) sensitive detector A detector whose response value depends on the mass flow rate of the component. Integral detector
Integral detector
A detector whose response value depends on the cumulative amount of the component. 2. 6.4 Differential detector
differential detector
A detector whose response value depends on the instantaneous reaction of the component. Thermal conductivity detector (TCD)
thermal conductivity detector A device that generates an electrical signal when the carrier gas and the effluent from the chromatographic column pass through the thermistor. The difference in thermal conductivity between the two causes a difference in resistance.
Flame ionization detector (FID)
flame ionization detector
A device that generates electrical signals when organic matter burns in a hydrogen flame. Alkali flame ionization detector (AFID)
2.6.4.3 3
alkali flame ionization detector A device that places alkali metal compounds near the nozzle of the flame ionization detector to increase the ions generated by nitrogen or phosphorus compounds, thereby enhancing the electrical signal.
2.6.4.4 Photoionization detector (PID) photojonization detector
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A device that uses high-energy ultraviolet rays to ionize components with ionization potentials lower than the ultraviolet energy and generates electrical signals under the action of an electric field.
2.B.4.5 Flame photometric detector (FPD)
flame phatumetric detector
A device that converts the light of characteristic wavelengths generated by sulfur- or phosphorus-containing compounds in a hydrogen-rich flame into electrical signals. 2.6.4.6 Electron capture detector (ECD) electron capture detector
A device that generates electrical signals by ionizing carrier gas molecules under the action of 8-particles generated by radiation sources such as 3H or 63Ni, forming a stable base current in an electric field. When components containing electronegative groups pass through, the captured electrons reduce the base current. 2.6.4,7 Microwave plasma (emission spectrometry) detector microwave piasma (emission spectrometry) detector uses microwave plasma to excite compounds, so that the elements contained produce characteristic emission spectra, which can be returned to H+ through the spectroscopic system to detect multiple pores.
2.7 Recorder
recorder
An instrument that records the time-varying electrical signals generated by the detection system. 2.B Integrator
integrator
An instrument that accumulates the electrical signals generated by the detection system according to time. 2.9 Microprocessor
micro -processor
A device used to record and process chromatographic data, and some can also control the operation of the chromatograph. 3 Stationary phase and mobile phase
3.1 Stationary phase
stationary phase
The substance that does not move in the chromatographic system and has a separation effect. .1.1 Adsorbent
adsorbcnt
Solid substance with adsorption properties and used for chromatographic separation. 3.1.2 Stationary liquid
Stationary liquid
Component of the stationary phase,
refers to the substance coated on the surface of the support to play a separation role, and is a liquid that is not easily selected at the operating temperature.
3.1.3 Support
Inert solid that supports the stationary liquid.
3.1.4 Chemically bonded phase
Chemically bonded phase
Stationary phase with specific groups bonded to the surface of the support by chemical reaction. 3.1.5 Porous pulymer beads
Porous pulymer beads of styrene and vinylene copolymers and other substances can be used as preparation materials alone or after removing the stationary liquid.
3.2 Mobile phase
mobile phase
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The gas used to carry the sample and the eluted components in the chromatographic column. 3.2.1 Carrier gas
Carrier gas
The gas used as the mobile phase.
4 Chromatographic parameters
4.1 Dead time (m)
dead ime
The time required for the components not retained by the fixed grid to appear from the injection to the peak maximum (Appendix A Figure A1). 4.2 Retention time ()
retention timc
The time required for the components to appear from the injection to the peak maximum (Appendix A Figure A1). 4.2.1 Adjusted retention time (r)
ad justed retention time
The retention time for the reduced dead time (Appendix A Figure A1). =h-
4.2.2 Corrected retention time (t)
corrected retention time
Retention time corrected by the pressure gradient correction factor. f=t
4.2.3 Net retention time (r)
net retention time
Adjusted retention time corrected by the pressure gradient correction factor. =
4.3 Dead volume (V)
dead volume
The volume of carrier gas required from injection to the peak maximum of the components not retained by the stationary phase. h-tur·F
4.4 Retention volume (V)
retention volume
The volume of carrier gas required from injection to the peak maximum of the components. =t·F
Adjusted retention volume (')
adjusted retention volume
Retention volume minus the dead volume.
4.4.2 Corrected retention volume (V.)
corrected retention volume
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Retention volume corrected by pressure gradient correction. VR=jVR
4.4.3 Net retention volume (V)
net rctention volume
Retention volume adjusted by pressure gradient correction. 4.5 Specific retention volume (V)
specificretention volume
Net retention volume per gram of fixed solution corrected to 273K. V=
4.6 Relative retention value (rt.,)
relativc retention value
The ratio of the adjusted retention value of a component to that of a reference component under the same operating conditions. ts
4.7 Retention index (1)
retention index
Retention index is a parameter of the retention index. The retention index of each n-alkane is defined as the number of carbon atoms multiplied by 100. 1 = 100
4.8 Phase ratio (8)
phase ratio
logvke+ -log'riz?---
1ogVt(2+1) - 1ogVr(2)
The ratio of the concentration of the gas phase to the concentration of the liquid phase.
4.9 Partition coefficient (K)
partition coefficient
The ratio of the concentration of a component in the fixed liquid to that in the mobile phase at equilibrium. 4.10 Capacity factor (K)
capacity factor
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The ratio of the mass of the component in the fixed liquid to the mass in the mobile comb at equilibrium. K=K--K-Jk
4.11 Column efficiency
column efficiency
The separation efficiency of the chromatographic column during the chromatographic separation process is mainly determined by the kinetic factors (operating parameters). It is usually expressed in terms of theoretical plate number, theoretical plate height or effective plate number. 4. 1.1 Theoretical plate number (n)
number of theoretical platc
The physical value that represents the column efficiency can be calculated by the following formula: n - 5.54 0
year. F1.2 Theoretical plate height (H)
height equivalent to a theoretical plate length of a single theoretical plate.
4.11.3 Number of effective plates (f)bzxz.net
number of effective plates
The quantity that indicates the column efficiency after deducting the dead time, calculated by the following formula: tefF = 5.54
4.12 Resolution (R)
resolutiont
The degree of separation between two adjacent chromatographic peaks, expressed as the ratio of the difference between the peak widths of the two components to their half-average peak widths (Appendix 1 Figure A2). (tR,-IR.)
R-2 (
4.13 Separation number (TZ)
separation number
The number of peaks that can be accommodated between two adjacent normal alkane peaks. 4.14
Response
response
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Ir[z+11 -tr(2]
[Wh/2](2) -[W/2](2+1)
The signal generated by the component passing through the detector. 4.14.1 Relative response (s)
relative response
The ratio of the response of a unit amount of substance to that of a unit amount of reference substance. Sm =
4.15 Correction factor ()
or sy=
correction factor
The reciprocal of the relative response value, its product with the peak product is proportional to the amount of substance. Sensitivity (S)
sensitivity
The rate of change of the response signal when the amount of substance passing through the detector changes △Q. S=
Detection limit (D)
delectability
The amount when the signal generated by the component entering the detector per unit volume of carrier gas or per unit time is equal to twice the baseline noise. D=
Linear range
linear range
The range in which the detection signal is linearly related to the amount of the substance being measured. 4. 19
Carrier gas flow rate (F.)
low rate of carricr gas
The volumetric flow rate of carrier gas measured at the temperature and pressure at the outlet of the chromatographic column and calibrated to the column temperature. H=F.
4.20Average linear velocity of carrier gas ()
mean lincar velocity of carrier gas The average velocity of carrier gas moving along the axial direction of the chromatographic column. T
4.21 Pressure gradient correction factor (j)
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pressure gradient correction factor is used to correct the pressure gradient caused by the compressibility of the mobile phase in the chromatographic column. 3
4.22 Liquid phase loading
liquid phase joading
-(P/P.)°-1
In the packed column, the relative amount of the solid phase and the adjusting phase (including the stationary phase and the carrier), expressed as a mass percentage. 4.23 Sample out-of-sample effect
cxtra-column effect
The effect of the gas path from the injection system to the detector outside the chromatographic column on the dust produced by factors such as injection method and post-column diffusion on the support efficiency.
5 Chromatogram and others
5.1 Chromatogram
chromatogram
The curve of the response signal generated by the effluent of the chromatographic column when it passes through the detector system versus time or carrier gas outflow volume. 5.2 (chromatographic) peak
(chromatographic) peak
The differential curve of the response signal generated by the effluent components of the chromatographic column when they pass through the detector system. 5.3 Peak base
peak basc
The dotted line connecting the starting point and the end point of the peak (CD in Appendix A Figure A1). 5.4 Peak height (h)
peak height
The distance from the peak maximum to the peak base (HE in Appendix A Figure A1). 5.5 Peak width (W)
peak width
The distance between the two points where the tangent line drawn at the points (F, G) on both sides of the peak intersects the peak bottom (KIL in Appendix A Figure A1). 5.6 Peak width at half height (W/2)
peak width at half height
The distance between the two points where a straight line drawn through the peak height and parallel to the bottom of the peak intersects the two sides of the peak (HJ in Appendix A Figure A1).
5.7 Peak area (A)
peak area
The area between the peak and the peak bottom (EJDC in Appendix A Figure A1). 5.8 Tailing peak
tailing peak
An asymmetrical peak whose trailing edge is more gradual than the leading edge. 5.8 Teading peak
An asymmetrical peak whose trailing edge is less gradual than the leading edge. 5.10 Ghost peak A peak that is not generated by the sample.
distorted peak
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A peak with asymmetrical shape, such as a tailing peak or a leading companion peak. 5.12 Baseline
baseline
The curve of the response signal generated when only the carrier gas passes through the detector system under normal operating conditions. Baseline drift
baseline drift
The slow change of the baseline with time.
Baseline noise (N)
baseline noise
Baseline fluctuation caused by various factors. 5.13 Normalization method
When all components in the sample show chromatographic peaks, the method of calculating the percentage content of each component after all the measured peaks are calibrated and normalized by the corresponding correction factors (the calculation formula is shown in Appendix B, B, 1). 5.141
Internal standard method
internal standard method
A method in which a known amount of an internal standard substance that can be completely separated from all components is added to a known sample, the peak value of the component to be tested is calibrated with the corresponding correction factor and compared with the peak value of the internal standard substance to obtain the percentage content of the component to be tested (see Appendix B B.2 for the calculation formula).
5.15 External standard method
external standard method
Under the same operating conditions, an equal amount of a sample and a standard sample containing the component to be tested are subjected to chromatographic analysis, the peak values ​​of the component to be tested in the sample and the standard sample are compared to obtain the content of the component to be tested (see Appendix B B.3 for the calculation formula). Absolute method
absolute method
Based on the relationship between the peak value and the amount of the component to be tested (measured by weight or volumetric analysis, etc.) obtained in advance, the peak value of the component in the known sample is measured under the same operating conditions and its content is obtained. 5.17
addition method
After measuring the peak values ​​of the component to be tested and an adjacent component in the sample, a certain amount of the component to be tested is added to a known amount of the sample, and then the peak values ​​of the two components are measured to calculate the percentage of the component to be tested (the calculation formula is shown in B.4 in Appendix B). 5.18 elution
elution
The process in which the carrier gas carries the component forward in the chromatographic column and flows out of the chromatographic column. Band broadening
band broadening
The phenomenon that the band width of the component increases during the movement of the component in the chromatographic column due to the influence of factors such as longitudinal diffusion and mass transfer resistance. 5.20 degree blowing
backflushing
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After some components are eluted, the carrier gas is passed through the chromatographic rod in the opposite direction to make some components move in the opposite direction. Aging
conditioning
The limit of the chromatographic column at the operating temperature. 5.22
column bleeding
column bleeding
The phenomenon that the fixed liquid is discharged with the carrier gas.
6 Symbols
Peak area, cm2
Peak area of ​​component i, cm2
Peak area of ​​reference substance, cm
Concentration of component in mobile phase, /ml
Concentration of component in fixed phase, /m1
Detection limit, m/m1 or 8/s
Carrier gas volume flow rate corrected to column temperature, ml/minCarrier gas flow rate at column outlet, ml/min
Paper size, mm
Retention index
Distribution coefficient
Length, m
Noise, mV
Column inlet, MPa
Column, MPa
Variation of the amount of substance
Separation
Variation of the response signal
Sensitivity, mV.nl/mg or mV.ml/ml (concentration detector), A./g or mV.s/g (mass spectrometer) Room temperature expressed in thermodynamic temperature, K
Column temperature expressed in thermodynamic temperature, K
Separation number
Specific retention volume, ml/g
Volume of gas phase in torr, volume of liquid phase in column, ml
Dead volume, ml
Net retention volume, ml
Preservative volume, ml
Adjusted retention volume, ml
Adjusted retention volume of component i, ml
Adjusted retention volume of reference component, m
Correction retention volume, m
Volume of reference substance, m!
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Z,Z+1 are the normal alkanes with carbon number Z,Z+1 appearing before and after the spectrum of component i respectively. Correction factor
Peak height, cm
Pressure gradient correction factor
Capacitance factor
Mass of component 1, B
Mass of stationary liquid, name
Mass of reference substance, 8
Number of theoretical plates
Number of effective plates
Relative retention value
Relative response value
Relative mass response value| |tt||Relative volume response value
Dead time, min
Net retention time, min
Retention time, min
Adjusted retention time, min
Adjusted retention time of component i, nin
Adjusted retention time of reference component, min
Corrected retention time, min
Average linear velocity of carrier gas, cm/s
Peak width, cm (or expressed in time, mia) Half-height, cm (expressed in time, min) Phase ratio
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