EN 1528-1-1996 pdf download.Fatly food — Deteimination of pesticides and polychiorinated biphenyls (RBs — Part 1: General.
3.4 Determination
Gas chromatography (GC) with various detectors, e.g. electron-capture detector (ECD), the thermionic detector (P- or NIP- mode), the flaiuephotomuetric detector (FPD), the I lall detector or mass spectronie’t.ry (MS) as appro)nate.
3.5 Confirmatioii
Procedures to contbm 11w identity and quantity of ob.served resi(lues, particularly in those ca.ses where it would appear that the maximum residue limit has been exceeded.
4 Reagents
4.1 General
Unless otherwise stated, use reagents of the highest purity (i.e. for residue analysis) and only distilled or demineralized water if possible; if this is not possible, redistil the water, solvents, and reagents used as descnbed in annex B and check their purity (see 4.2). Note that ion-exchange resins used for denilneralized water can be a source of interferences. Purify and penodically activate adsorbents according to the requireluents of the different analytical methods; check their purity (see 4.2).
Take evemy precaution to avoid possible contamination of water, solvents, adsorbents etc. from plastics an(l nibber materials. If an interference is encountered in a reagent blank determhiation, then check the P11fltY of all reagents used.
4.2 Check for purity of reagents
4.2.1 Solvents
concentrate solvents by the factor involved in the respective method to be u.Sc(L Th$ for purity by GC under the same conditions as used in the method. The chromatograni should not show any interfering impurity Extract or concentrate acetonitrile, (linlethylformanude and dichlorometh;uie in the same volume as used in the method and examine the resulting soluflon as above by GC.
4.2.2 Water
Extract 10 parts by volume of water with one part by volume of n-hexane or light petroletrni, dichioroniethane or any other non water miscible solvent used in the method. Separate the organic phase, concentrate by the factor involved in the respective method and test for purity by GC under the same conditions as used in the method. The chromatogram should not show any interfering impurity
4.2.3 Inorganic salts
Extract inorganic sails, for example sodituu chloride, after Inuilicat]on according to annex 11 or the requiremenis of the different analytical methods and any aqueous solution used, with ,i—hexane or light. Iwt-n)letnn, dichloroniethane or any other non water nn_scible solvent used in the method. Concentrate the extract by the factor involved in the respective method and test by GC under the sanle conditions as used in the methxl. The chromatogram should not show any interfering impunty.
4.2.4 Adsorbents
Eliite an amount of a(lsorbent equal to that used in the analytical nietliod with the corre.sx)n(hng type aiid vohinw of solvent or solvent nuxture. Concentrate the etuate a.s rn(heated in the analytical method and Lest for purity by GC. The chroniatogram should not show any interfering unl)urlty Check the activity of adsorbent.s reguliuiy, for example as described in 5.3.9 of EN 1528-3: 1996.
4.2.5 Standard materials and solutions Use materials of at least 95 % pLu•Ity and traceable (luality as stan(Iards for residue analysis. Ensure dilute solutions are prepared an(l dleCk(d frequently; and that standard solutions are stored in glass bottles in a refrigerator and evety precaution is takeii to avoid possil)le contanunation from plastics or rubber materials. Ensure that the standard solutions are not (lireetly exposed to suuthght or ultraviolet light. Examine analytical standards for inlf)urltws. When stored at —20 C, standard materials are generally stable for at least a year or two. To allow equilibration, allow the stan(lar(Ls to come UI) to flX)flI temperature before the containers are opened. Stock solutions of concefltratiofl 1 mg/mi, if kept in a spark proof refrigerator (at about. 4 ‘C), are usually stable for 2 103 months.
NoTE 1. Changes in voiwne (tue to solveni evaporation, for example through the space between a glass stopper and the neck of a flask, can be a source of error.
N( )TE 2. lxpcnenre hits shown IlLat errois ifltflMtU(C(I ill 11W
preparation, handling and storage of standards and standard solulions are major sources of Inaccuracies. ExperIences obtained by other national, European and mieniatmonal bodies shomiki he observed 191. 1 H)[
4.3 Safety aspects associated with reagents
4.3.1 General
The ana1yss of iwstwule and PCB congent’r residues in a food matrix includes the use of several hazardous clienüeals.
1’he list given in 4.3.2 shows some apI)rol)rlate sa1ity preeautions which shall be observed at all times.EN 1528-1-1996 pdf download.