ISO 23322 pdf free download
ISO 23322-2021 pdf free download.Paints and varnishes – Determination of solvents in coating materials containing organic solvents only – Gas-chromatographic method.
6 Apparatus
6.1 Gas chromatograph
6.1.1 General
The gas chromatograph shall be suitable for use with capillary separation columns and meet the conditions specified in fL.LZ to 1A.
All of the instrumental parts coming into contact with the test sample shall be made of a material, e.g. glass, which is resistant to the sample and will not change it chemically.
6.1.2 Sample injection system
6.1.2.1 General
The method provides a choice between three sample injection systems:
— hot-injection system with sample splitter;
— cold-injection system with sample splitter;
— headspace injector.
6.1.2.2 Hot-injection system
The instrument shall have a variable-temperature injection block with sample splitter. The injection temperature shall be capable of being set to an accuracy of 1 K. Standard operating temperature shall be between 250 °C and 280 °C.
NOTE It is useful to use silanized glass wool to retain non-volatile constituents. The active sides of silanized glass wool can be a sink for organic compounds and significantly influence the recovery rate in the lower range of the method. The occurrence of adsorption is revealed by peak tailing, in particular with components of low volatility and/or high polarity.
6.1.2.3 Cold-injection system
The cold-injection system shall be provided with temperature programming for heating from ambient to 300 °C including a sample splitter for split operation.
NOTE It is useful to use silanized glass wool to retain non-volatile constituents. The active sides of silanized glass wool can be a sink for organic compounds and significantly influence the recovery rate in the lower range of the method. The occurrence of adsorption is revealed by peak tailing, in particular with components of low volatility and/or high polarity.
6.1.2.4 Headspace Injection
It shall be possible to set the following values:
— controlled sample temperature: 150 °C;
— controlled transfer line and dispensing valve temperatures: 160 °C;
— temperature hold time: 4 mm.
6.1.3 Oven
The oven shall be capable of being heated between 40 °C and 300 °C, both isothermally and under programmed temperature control. It shall he possible to set the oven temperature to within 1 K. The
final temperature of the temperature program shall not exceed the maximum operating temperature of the separation column (see manufacturer’s instructions).
6.1.4 Detector
6.1.4.1 General
One of the following two detectors shall be used.
6.1.4.2 Mass spectrometer (MS) or other mass-selective detector (MSD)
To prevent condensation, the detector temperature shall be at least 10 K above the maximum oven temperature.
6.1.4.3 Flame ionization detector
The flame ionization detector (FID) is operated at temperatures between 230 °C and 300 °C. To prevent condensation, the detector temperature shall be at least 10 K above the maximum oven temperature. The detector gas supply, injection volume, split ratio and gain setting shall be optimized so that the signals (peak areas) used for the calculation are proportional to the amount of substance.
6.1.5 Capillary separation column
The column shall be made of glass or fused silica. Columns of sufficient length to resolve volatiles and of maximum internal diameter 0,32 mm, of a suitable polarity and with a suitable film thickness shall be used.
6.1.6 Analytical system performance criteria
The analytical system performance criteria shall be demonstrated. The resolution, R, of the peaks to be separated shall be at least 1,5.
For the compounds under investigation it has to be ensured that the sample concentration lies within the quantification range of the analytical system.
NOTE The limit of quantification can deviate for single compounds. If necessary, the compound specific limit of quantification can be determined for the considered single compound(s).
6.2 Injection syringe
The injection syringe for hot or cold injection systems shall have a capacity of at least twice the volume of the sample to be injected into the gas chromatograph.
6.3 Data processing
Suitable software shall be used for integration, calibration, quantification and other data handling processes.
6.4 Sample vial
A suitable sample vial is one made of chemically inert material, for example glass, which can be sealed for example with a rubber membrane having a coating of poly(tetrafluoroethylene) (PTFE). The vessel shall be filled to about 90 % of capacity.ISO 23322 pdf download.
