Price of the test:
$27 per analysis
Acceptable Matrices:
This method is universal for the determination of nitrogen content and can be used for nearly all food products.
Unacceptable Matrices:
Pure oils and shortenings cause fires in the instrument and almost always must be assayed by the Kjeldahl method.
Limit of Detection:
0.1% Nitrogen
Limit of Quantitation:
0.125% Nitrogen
0.648% – 0.798% Protein (factor dependent)
Sample Size Requirements:
20 grams
Equipment:
Protein/Nitrogen by combustion analyzer.
Reportable Units:
% Protein
Turn Around Time:
7-9 Business Days
Is Rush Available?
Yes
Method Reference:
AOAC 992.15; AACC 46-30
Method Description:
The sample is completely combusted at high temperature in the presence of pure O2 (99.9%). Combustion products are H2O, CO2, NOx, and N2. Water vapor, oxygen and CO2 are removed from the resulting gas stream by a series of thermoelectric coolers and chemical sorbents. NOx is reduced to N2 when passed through a column that is packed with hot copper. The resulting N2 is passed to a thermal conductivity detector where it is quantified (helium is the carrier gas). Protein is then calculated from the nitrogen content using a published conversion factor (e.g. 5.70 for wheat).
Additional Information:
Available Protein Factors:
6.25 – general purpose food products/ingredients (Default) except as noted below
5.70 – wheat, wheat flour, and wheat flour breads
6.38 – dairy
5.46 – peanuts and brazil nuts
5.18 – almonds
5.30 – Other tree nuts coconuts (butternuts, cashews, chestnuts, hazelnuts, hickory nuts, pistachios, walnuts, pecans.)