ISO 17180:2013 pdf free

ISO 17180:2013 pdf free.Animal feeding stuffs一Determination of lysine, methionine and threonine in commercial amino acid products and premixtures
Calculate the approximate mass of test portion (mtp premix) in grams based on the amino acid with lowest expected values (Wexp) as described in 5.3.2. Use for extraction a test portion amount to ensure that all amino acids peak areas are in the linear range of the calibration. Weigh in this amount and transfer quantitatively with 0,1 mol/l HCl (3.10) intoa 1 I volumetric flask. Dissolve in about 900 ml of 0,1 mol/1 HCI, while stirring with a magnetic stirrer (4.5) nfor 30 min. Fill to volume with 0,1 mol/1 HCl and mix well. Dilute and add norleucine solution (3.11.1), following the procedure specified in 3.11.3.2 for the preparation of the calibration solution.
If the premix contains other amino acids with higher expected contents, dilutions using an aliqout of less than 1 ml of extract plus 2,5 ml norleucine may be prepared.
If the sample solutions are not to be examined the same day, they shall be stored below 5。C for not more than 3 days.
Filter a suitable amount of the test solution through membrane filter unit (4.6) into an auto sampler vial and inject into the analyser or HPLC system (4.10). The injection volume normally is 20 ul to 50 ul
The chromatographic system is required to separate the amino acids from each other and from any other components (e.g. ammonia, amines, peptides or amino sugars).
The analyte amino acids are required to be 100 % baseline separated from all other peaks that are eluted to avoid erroneous results caused by peak overlap. The chromatographic system is required to provide a linear response over the concentration range of the standard curve.
Contents in samples are calculated using the result of the initial calibration solution (3.11.3). In order to check there is no drift, inject the calibration solution as quality control after every four test solutions. If the recovery of these control solutions is outside the range 99 % to 101 %, repeat the analysis.
Determine the peak area of the amino acid peaks in the calibration solutions and test extracts by integration and calculate the content of the amino acid as a percentage mass fraction of the test portion as specified in 6.2 or 6.3.ISO 17180 pdf download.