DIN EN 14105 pdf free download

DIN EN 14105 pdf free download. European Standard EN 14105 : 2003 has the status of a DIN Standard.
2 Principle
Transformation of the glycerol and of the mono- and diglycerides into more volatile silylated derivatives in presence of pyridine and of N-methyl-N-trimethylsilyltrifl uoroacetam ide (MSTFA).
Analysis of the silylated derivatives by gas chromatography on a short capillary column with thin film thickness, with an on-column injector or equivalent device, and flame ionization detection.
After a calibration procedure, the quantification is carried out in the presence of two internal standards:
— 1 ,2,4-butanetriol intended for the determination of the free glycerol;
— 1 ,2,3-tricaproylglycerol (tricaprin) intended for the determination of the glycerides (mono-, di- and tn-).
3 Reagents
Use only reagents of recognized analytical grade, unless otherwise specified.
3.1 N-methyl-N-trimethysilyltrifluoroacetam ide (MSTFA).
3.2 Pyridine, stored on molecular sieve.
3.3 n-Heptane.
3.4 1,2,4-Butanetriol, (internal standard No.1).
3.5 1 ,2,3-Tricaproylglycerol (tricaprin), (internal standard No.2).
3.6 Reference substances : glycerol, 1 -monooleoylglycerol (monoolein), 1 ,3-dioleoylglycerol (diolein),
1 ,2,3-trioleoylglycerol (tnolein), pure – GLC standard grade.
3.7 Internal standard No. 1 stock solution, 1 mg/mI.
Accurately weigh approximately 50 mg (to the nearest 0,1 mg) of 1 ,2,4-butanetnol (3.4) in a 50 ml volumetric flask (4.4) and make up to the mark with pyridine (3.2).
3.8 Internal standard No. 2 stock solution, 8 mg/mI.
Accurately weigh approximatively 80 mg (to the nearest 0,1 mg) of 1,2,3-tricaproylglycerol (3.5) in a 10 ml volumetric flask (4.5) and make up to the mark with pyridine (3.2).
3.9 Glycerol stock solution, 0,5 mg/mI.
Accurately weigh approximately 50 mg (to the nearest 0,1 mg) of glycerol (3.6) in a 10 ml volumetric flask (4.5) and make up to the mark with pyridine (3.2). Using a pipette (4.7) transfer 1 ml of this solution into a 10 ml volumetric flask (4.5) and make up to the mark with pyridine (3.2).
3.10 Glyceride stock solution, 5 mg/mI.
For each reference glyceride, mono-, di- and triolein (3.6), accurately weigh approximately 50 mg (to the nearest
0.1 mg) in a 10 ml volumetric flask (4.5) and make up to the mark with pyridine (3.2).
3.11 Monoglycerides1), commercial mixture.
Made up of monopalmitoylglycerol (monopalmitin), monostearoylglycerol (monostearin) and of monooleoylglycerol (monoolein), present in quantities having an identical mass.
Prepare a stock solution of this mixture by weighing approximately 100 mg in a 10 ml volumetric flask (4.5) and make up to the mark with pyridine (3.2).
3.12 Calibration solutions
Prepare daily four calibration solutions by transferring into a series of vials (4.6) the volumes of stock solutions of reference substances (3.9 and 3.10) and of internal standards (3.7 and 3.8) given in Table 1, using microsyringes (4.8 and 4.9). The choice of the appropriate syringe shall be done according to Table 1. Do not use syringe at maximum capacity, but dispense the half volume twice (I. e.: in case of 100 iii dosing using a 100 iI syringe, load 50 .tl twice). Be sure that needle and body of syringe are free from air bubbles, and measure volumes only by difference (I. e.: when dispensing 80 jii, fill syringe up to 100 iii and supply solution up to the 20 tl mark).
NOTE The silylated standard solutions are only stable one day.
5 Procedure
5.1 Preparation and analysis of the calibration solutions Using a microsyringe (4.8), add 100 μl of MSTFA (3.1) to each of the four calibration solutions (3.12), close hermetically the vials and shake vigorously and avoid contact with moisture. Store 15 min at room temperature, then add 8 ml of heptane (3.3) using a graduated cylinder (4.11). Analyse 1 μl of each reaction mixture by gas chromatography under the conditions defined above (4.3). Each reaction mixture gives rise to two chromatographic analysis. Samples are stable for some hours after derivatisation.DIN EN 14105 pdf download.