IEC 61619:1997 pdf download – lnsulating liquids – Contamination by polychlorinated biphenyls (PCBs)-Method of determination by capillary column gas chromatography

IEC 61619:1997 pdf download – lnsulating liquids – Contamination by polychlorinated biphenyls (PCBs)-Method of determination by capillary column gas chromatography.
IEC 61619 specifies a method for the determination of polychlorinated biphe nyl (PCB) concentration in non-haloge nated ins ulating liquids by high-res olution capillary column gas chromatography using an electron capture detector (ECD).
The method gives the total PCB content and is especially useful when a detailed analysis of PCB congeners is necessary. Other methods, such as WC 60997, may be used when a less detailed analysis is acceptable.
The method is applicable to unused, reclaimed (including dechlorinated and chemically and/or physically treated), or used insulating liquids contaminated by PCBs.
2 Normative reference
The following normative document contains provisions which, through reference in this text, constitute provisions of this normative document. At the time of publication, the edition indicated was valid. All normative documents are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative document indicated below. Members of IEC and ISO maintain registers of current valid International Standards.
IEC 60475: 1974, Method of sampling liquid dielectrics
3 Definitions
For the purposes of the International Standard, the following definitions apply:
3.1 Polychloiinated biphenyl (PCB)
A biphenyl substituted by one to ten chlorine atoms.
NOTE — For legal purposes, congenei with one, two or ten chlorine atoms flay be excluded from this definition.
3.2 Congener
All the chlorine derivatives of biphenyl, irrespective of the number of chlorine atoms, are termed congeners.
NOTE — There are 209 possible PCB congeners.These are listed in table B.1. The congener numbers (ILTPAC)* are for easy identification they do not represent the order of chromatographic elution.
4 Principle
The PCB congeners are determined by temperature programmed gas chromatography. The chrornatograph uses a high-efficiency capillary column to separate the PCBs into single or small groups of overlapping congeners.
The sensitivity of the electron capture detector (ECD) may he reduced by the presence of mineral oil. In this method the sample is diluted 100 tinies to reduce this effect to a minimum.
A sample preparation (clean-up) procedure is used to remove most of the impurities likely to inteifere with the determination.
Reference compounds are included to enable times (ERRTs) which are compared to a data file of unresolved congeners. An internal standard is
calculation of experimental relative retention of peak ERRTs to identify individual or groups added for quantification.
Re lathe relative identified give total
response factors response factors peaks to quantify PCB content.
(RRF), taken from the data files (9.1), corrected by experimental (ERRFs) obtained from reference compounds, are applied to the individual (or groups of) congeners, and the values summed to
5 Reagents and auxiliary materials
5.1 Reagents and standards
All reagents and materials, including those for clean-up, shall be free from PCB contamination and compounds responding to the ECD.
5.1.1 Solvent
Hexane, heptane, cyclohexane or isooctane (2,2,4-trirnethylpentane), high purity, free from PCB contamination and low in compounds that respond to the ECD.
5.1.2 Hexachlombenzene
Purity 99 % at least, used for checking detector sensitivity.
5.1.3 Insulating liquid
An insulating liquid, checked to be free from PCBs or other interfering substances, of the same type as is present in the sample.
5.1.4 Congener3O solution (C 30)
10 mg/I in solvent (5.1.1) purchased in solution or prepared from pure material (purity 99 % at Ic as t).
5.1.5 Congener 209 (DCB), de cachiorobiplienyl solution
10 mg/I in solvent (5.1.1) purchased in solution or prepared from pure material (purity 99% at least).