EN 62321-8-2017 pdf download.Determination of certain substances in electrotechnical products- Part 8: Phthalates in polymers by gas chromatography-mass spectrometry (GC-MS), gas chromatography-mass spectrometry using a pyrolyzer/thermal desorption accessory (Py/TD-GC-MS) (IEC 62321-8:2017).
surrogate recovery is not within these limits, the sample shall be re-extracted and reanalysed.
e) From the results of the five calibrants (according to Table 4), calculate the average response (peak area) for the internal standard. The internal standard (IS) response for each sample shall be monitored throughout the analysis and compared to the average. If at any point in the analysis the IS response fluctuates below 50 % or above 150 % of the average, the sample is deemed out of control and shall be re-analysed. If the IS response Is still out of range, check the results of the duplicate extract. If both are out of range and biased in the same direction, report data as suspect due to matrix effects.
f) A solvent blank run between each injection is recommended in order to be certain that there is no analyte carry-over from sample to sample. This is particularly important when samples containing high levels of each phthalate and/or potential interference are analysed. Failure to determine that the instrument is free of contaminating analytes may result in falsely elevated results. It is recommended that the solvent contain a small amount of silylating agent (BSA, BSTFA) to maintain the inertness of the injector liner.
g) The retention time of analytes having an Identification mass corresponding to each phthalate shall be within ±1 % of standards used in the calibration solutions. Use of retention times as a confirmation criterion is a widely accepted practice.
11.2.2 Limit of detection (LOD) or method detection limit (MDL) and limit of quantification (LOQ)
A limit of detection (LOD) or method detection limit (MDL) study shall be completed before conducting this testing and each time there is a significant change in the method or instrument type. The LOD or MDL is most appropriately determined experimentally by performing replicate, independent measurements on low-level or fortified sample matrices (e.g. plastic) carried out through the entire test pracedure, including extraction. A minimum of six replicates and arialyte concentrations of 3 to 5 times the estimated LOD or MDL shall be performed for this analysis. The complete LOD or MDL for an entire test procedure is determined by multiplying the standard deviation of the replicates by an appropriate factor. The International Union of Pure and Applied Chemistry (IUPAC) recommends a factor of 3 for a minimum of six replicates, whilst the Environmental Protection Agency (EPA) utilizes a one- sided confidence interval with the multiplier equal to Student’s s value chosen for the number of replicates and the level of confidence (e.g. , = 3,36 for six replicates for 99 % confidence). All analyses used to calculate an LOD or MDL shall be consecutive.
a) Mill approximately 2 g of suitable polymer from a pure source known not to contain DIBP, DBP, BBP, DEHP, DNOP, DINP, DIDP or other compounds that may interfere with the analysis.
b) Weigh out 500 mg of the milled polymer and place it in a new extraction thimble. Repeat this step six more times.
c) Place the extraction thimble in the Soxhiet extraction apparatus.
d) Spike the thimble with 0,25 ml of each phthalate (100 .LgIml) and surrogate standard (100 ug/ml) stock solution (8.5,1.2) approximating the concentration of the lowest concentration calibrant.
e) Use the procedure (extraction according to 8.2.1.3 or 8.2.1.4) to extract each of the samples. Analyse accordingly.
f) The percent recovery of each phthalate shall be between 70 % and 130 %. If the recovery is above or below these limits, the analysis shall be repeated. If the recovery is outside of these limits a second time, the entire extraction and analysis procedure shall be repeated.
g) Each phthalate shall have a calculated MDL of less than or equal to 50 mg/kg. If the calculated MDL for any of the phthalates Is above these limits, the procedure, extraction and analysis shall be repeated for that phthalate.
h) The limit of quantification (LOQ) for each phthalate shall be, at a minimum, three times the respective MDL. Unlike the MDL, which relates to detection only, the limit of quantification (LOQ) is a concentration that can be accurately quantified for a given compound.
IEC 62321-8:2017 © IEC 2017 —29—
If the required MDL cannot be met, a concentration step can be added to the extraction procedure. Since the concentration step will also increase the resin concentration in the extract, a clean-up step is also recommended for each sample. This will extend the life of the column and reduce the frequency of Instrument maintenance. If the concentration and / or clean-up steps are used in the analysis, they shall also be used for the MDL samples.
11.3 PyITD.GC-MS method
11.3.1 Sensitivity
Instrumental sensitivity shall be confirmed by the S/N ratio of 50 ng phthalates (S/N > 30).
The confirmed S/N ratio shall be greater than 30.
Reference polymer material (100 mg/kg) is recommended as the sensitivity check sample. Put approximately 0,5 mg of the punched-out, cut or powdered reference polymer material into the sample cup (Figure 1.1).EN 62321-8-2017 pdf download.
EN 62321-8-2017 pdf download
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