1、Standard layout for a method of chemical analysis by gas chromatography Plan normalise de methode danalyse chimique par chromatographie en phase gazeuse /- First edition - 1974-04-01 UDC 543.544 : 389.6 R,d1, I: ;: j j jlQj Ref. No. IS0 2718-1974 (E) Descriptors : chemical analysis, chemical tests,
2、chromatography, gas chromatography, specifications. Price based on 7 pages Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-FOREWORD IS0 (the International Organization fo
3、r Standardization) is a worldwide federation of national standards institutes (IS0 Member Bodies). The work of developing International Standards is carried out through IS0 Technical Committees. Every Member Body interested in a subject for which a Technical Committee has been set up has the right t
4、o be represented on that Committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the Technical Committees are circulated to the Member Bodies for approval before their acceptance as Internati
5、onal Standards by the IS0 Council. International Standard IS0 2718 was drawn up by Technical Committee ISO/TC 47, Chemistry, and circulated to the Member Bodies in April 1972. It has been approved by the Member Bodies of the following countries : Austria Belgium Chile Czechoslovakia Denmark Egypt, A
6、rab Rep. of France Germany India Ireland Israel Italy Netherlands New Zealand Portugal Romania South Africa, Rep. of Spain Sweden Switzerland Thailand Turkey United Kingdom U.S.S.R. This International Standard has also been approved by the International Union of Pure and Applied Chemistry (IUPAC). N
7、o Member Body expressed disapproval of the document. 0 International Organization for Standardization, 1974 l Printed in Switzerland Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license fr
8、om IHS-,-,-INTERNATIONAL STANDARD IS0 2718-1974 (E) Standard layout for a method of chemical analysis by gas chromatography 0 INTRODUCTION Gas chromatography is a separator-y and analytical technique which is being utilized increasingly, particularly for check analyses within the same laboratory, fo
9、r check analyses for acceptance between laboratories, for analyses of unknown samples, and for analytical research. Because of the diversity of apparatus and working methods, it seems desirable to establish a standard layout for the basic characteristics and instructions of a technical nature which
10、should be specified for either of the following purposes : - to present a report of an experimental investigation or of a check analysis in a scientific publication or in a document of a commercial nature. The authors of such publications should give all the necessary instructions to enable the docu
11、ment to be understood and the procedure to be followed with the aid of identical or closely related equipment. - to draw up procedures capable of application in laboratories equipped with different apparatus. Only those details that are sufficient to allow the method to be put into practice and repr
12、oducible results to be obtained, within determined limits of precision, should be given. The list of characteristics enumerated in this standard layout should not be regarded as exhaustive, nor is there any intention to imply that all these characteristics should be given and explained in publicatio
13、ns and procedures. The authors or editors of such documents should select from this list the characteristics necessary to achieve one or other of the two objectives mentioned above. In particular, from the point of view of standardization, the details given in a particular standard should be decided
14、 at the conclusion of an experimental investigation carried out in several laboratories and after a comparative analysis of the results. Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without licens
15、e from IHS-,-,-IS0 2718 -1974 (E) STANDARD LAYOUT 1 TITLE 2 SCOPE AND FIELD OF APPLICATION 3 MATERIALS 4 APPARATUS 5 SAMPLE 6 PROCEDURE 7 EXPRESSION OF RESULTS 8 TEST REPORT 9 HAZARDS 2 Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo re
16、production or networking permitted without license from IHS-,-,-IS0 2718 -1974 (E) NOTES ON THE APPLICATION OF THE STANDARD LAYOUT 1 TITLE 4.3 Columns (and pre-column) The title of the publication or standard shall express its contents without any ambiguity, mentioning briefly the products concerned
17、 and the nature of the analysis. 4.3.1 Number - Grouping and switching of the columns. 4.3.2 Column 2 SCOPE AND FIELD OF APPLICATION This clause shall contain precise details of the subject of the investigation or standard, and particularly of the field of application of the method described. It sha
18、ll include a brief summary of the investigation or standard which shall be suitable for use as an abstract. 3 MATERIALS Mention any hazard present and cross-refer to clause 9, “Hazards”. 3.1 Carrier gas and auxiliary gases - Nature and commercial description. - Content of impurities and method of pu
19、rification. 3.2 Materials for the preparation of calibration samples. 3.3 Cross-refer to 4.3 for column details, including packing and preparation. 4 APPARATUS 4.1 Type of apparatus 4.1.1 Characteristics of the assembly (oven, temperature regulation . . .), special devices. 4.1.2 Devices for the con
20、trol of pressure, or of the flow of carrier gas and auxiliary gases. 4.2 Injection device - Type. - Material. - Characteristics. - Miscellaneous accessories. - Nature of the column (material and treatment). - Length and packed length. - Internal and external diameters. - Form (U, W or helical . . .)
21、. - Radius of any curve. 4.3.3 Packing 4.3.3.1 Support - Nature (description, batch . . .). - Particle size. - Treatment, if any. 4.3.3.2 Stationary phase - Chemical nature. - Degree of impregnation : indicate, without ambiguity, the proportions of stationary phase and support (for example, in grams
22、 of stationary phase per 100 g of support, or as the percentage by mass of stationary phase in relation to the total of support + phase). 4.3.3.3 Active adsorbent - Nature. - Particle size and/or other physical characteristics. - Activation. 4.3.3.4 Other packing - Modified adsorbents. - Porous poly
23、mers. 4.3.3.5 Method of packing and mass introduced. 4.3.4 Efficiency and resolution 4.3.4.1 Efficiency under given conditions. 4.3.4.2 Resolution under given conditions. _ 4.4 Flow splitter Copyright International Organization for Standardization Provided by IHS under license with ISONot for Resale
24、No reproduction or networking permitted without license from IHS-,-,-IS0 2718-1974 (E) 4.5 Detector - Type. - Characteristics. - Associated electronic device (characteristics of the electrometer). 4.6 Recorder and/or integrator - Type. - Sensitivity. - Impedance. - Response time. 4.7 Electronic data
25、 processing system 4.8 Accessories 5 SAMPLE - Nature : name; description; supposed composition. - Method of sampling and storage. - Special considerations that may be involved during the analysis (volatility, stability, explosivity, toxicity, etc. with reference to clause 9 “Hazards”, as appropriate
26、). - Preliminary treatment (distillation, dissolution, methylation or any other treatment). 6 PROCEDURE 6.1 Setting up the apparatus 6.1 .I Injector - Temperature and permitted limits. 6.12 Oven and column 6.1.2.1 Temperatures - Isothermal conditions : temperature and permitted limits. - Programmed
27、conditions : initial period and temperature; programme of rise in temperature; temperature and final period. 6.1.2.2 Flow of carrier gas - - 6.1.3 - 6.1.4 - - - 6.1.5 - - 6.1.6 Isobaric conditions : rate of flow; pressures at inlet and outlet of the column. Programmed conditions : initial period and
28、 initial flow rate; programme of flow variation; back flushing. Flow splitter Split ratio. Detector Temperature and permitted limits. Electrical controls. Regulation of auxiliary gases. Recorder Chart speed. Initial attenuation, lntegra tor 62 Calibration 62.1 Methods of calibration The following ar
29、e the most generally used methods of calibration : 6.2.1.1 Internal normalization method All the constituents are eluted and all the peaks measured. The measurements are normalized to 100, with the calibration factor determined either by calculation (see 6.2.3) or by measurement at each analysis (se
30、e 6.2.2.1). 62.12 Internal standard method A known quantity of a known substance, whose peak does not interfere with any other peaks, is added to the sample. The measurement of the peaks of the different constituents, corrected by the respective calibration factors, is compared to that of the peak o
31、f the added known substance. 62.1.3 External standard method A certain quantity of the sample and an equal amount of a known synthetic mixture are subjected in turn to chromatography. The measurements of the resultant peaks are compared. 4 Copyright International Organization for Standardization Pro
32、vided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IS0 2718-1974 (E) 6.2.1.4 Absolute method A known quantity of sample is injected. By measurement of the peaks, and depending on the adjustment of the apparatus, the quantity of const
33、ituent corresponding to each peak is determined on the basis of a general relationship of peak area to mass. This relation is derived from, for example, gravimetric, volumetric or coulometric analysis and can be presented in the form of tables, curves, charts, etc. 6.2.1.5 Addition method The follow
34、ing are subjected in turn to chromatography : - the original sample. The peaks corresponding to the constituent to be determined and to a constituent giving a neighbouring peak are measured. 6.2.3.1 In the form of curves : - selection of scales; - method for drawing up charts; - particular forms of
35、presentation. - a reference mixture of a quantity m of the sample and a known quantity mr of the constituent to be determined. The peaks corresponding to the constituent to be determined and to the constituent with the neighbouring peak are again measured. 6.2.3.2 In the form of factors : - method o
36、f calculation from the results of chromatography of standard mixtures; indicate the units; The conditions of application of the five methods of - method of calculation from theoretical data (gas calibration mentioned in 6.2.1 .I to 6.2.1.5 are summarized density balance, Sternberg Gallaway and Jones
37、 method, in the table below. etc.); 6 2 2 Standard mixtures 6.2.2.1 Operating frequency : - calibration sample used for the determination of factors, whether once only or for periodical recalibration (the period to be indicated); - calibration samples used at each analysis. 6.2.22 Method of preparat
38、ion of the standard mixture or of the series of standard mixtures. 6.2.2.3 Conditions specific to the use of standard mixtures in chromatography : - injection of known or identical quantities; - conditions for reproducibility in the regulation of the apparatus; - possible subsequent or simultaneous
39、analysis of the standard mixture. 6.2.3 Presentation of the calibration data - approximate estimations; the case where the factors are considered to be equal to 1; state and explain approximations when appropriate; rules to be followed in the case of unidentified peaks. 6.3 Test 6.3.1 Prepamtion of
40、the test portion (in the case of the internal standard method) or of the reference mixture (in the case of the addition method). - Volume or mass of the sample. - Volume or mass of the standard mixture or addition. - Method of mixing the standard mixture with the sample. Method I Eluted constituents
41、 I Detector Volume injected Operating conditions of the chromatograph Internal normalization method All constituents Internal standard method Constituents to be determined Linear Linear Optional Optional Stable during the analysis Stable during the analysis I External standard method I Constituents
42、to be determined Linear I ! Reproducible Stable during at least two consecutive analyses /IConstituents to be determined Optional Known reproducible “tforn r Addition method I Constituents to be determined Linear I Optional Stable during at least two consecutive analyses 5 Copyright International Or
43、ganization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IS0 2718-1974 (E) 6.3.2 Introduction of the test portion (and of the reference mixture in the case of the addition method) - Quantity injected. - Pr
44、ocedure. 6.3.3 Recording - Attenuation and changes in the attenuation and chart speed. - Period. 6.4 Examination of the chromatograms 6.4.1 6.4.2 - Standatd chromatograms Qualitative analysis - - - Order of elution of the constituents (peaks). Retention characteristics. Specification of possible int
45、erferences. Complementary methods of identification. 6.4.3 Quantitative analysis - Measurements effected (height of peaks, product height by retention distance, triangle constructed on the peaks, triangulation, planimetry, cutting and weighing, integration, etc.). - Calculations : transfer to calibr
46、ation curves or the use of charts; formulae to be applied. - Special methods. 7 EXPRESSION OF RESULTS 7.1 Qualitative analysis - Toxic hazards - Number of constituents found. - Explosive hazards - Names of the constituents identified. - Radioactive hazards. 7.2 Quantitative analysis - Results and me
47、thod of expression of the results. - Limit of accuracy of the results. - Limit of detection. 8 TEST REPORT This clause is intended to remind the operator that the following particulars are to be included in the test report : a) authority for the method used, for example, a citation of an official re
48、ference or of a reference from the scientific literature; b) the results, the method of expression used and, possibly, the formula for the calculation; c) any special details, as well as any unusual features noted during the analysis; d) any operation not included in the method, or regarded as optio
49、nal. 9 HAZARDS Materials known to present a hazard are to be noted as such in the appropriate clause, normally under clause 3. In addition, all hazards are to be grouped together and detailed in clause 9 under an appropriate heading, together with information about the precautions to be taken or reference to a suitable source of such information. Examples of headings which may be required are : 6 Copyright International Organization for S
