Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:13:p9
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 13 (pt 9/9)
Character Range: 872326–874096

calibration and retention time marking for the nC10 to nC40 hydrocarbons using approximately equal weights of nC10, nC16, nC34 and nC40 hydrocarbons dissolved in hexane (toluene can be added to assist dissolution).
    * At a minimum, run a 5-point calibration curve using the nC14, nC24 and nC36 hydrocarbons and a blank before analysis begins. Linearity should have a linear regression of >0.99.
    * At a minimum, run a daily check of the lowest calibration standard and the midpoint calibration standard to confirm stability of the calibration curve. Rerun the calibration curve if the low standard deviates by more than 30% from the curve or if the midpoint calibration standard deviates by more than 20% from the curve.

    13.3.7     Calculations
Calculation of TRH fractions in a sample:

>C10–C16 hydrocarbons (mg/kg) = A>C10-C16  x  C14 conc  x   Volext  x  F  x   100

     AC14   W  %DW

>C16–C34 hydrocarbons (mg/kg) = A>C16-C34  x  C24 conc  x  Volext  x  F  x   100

     AC24           W   %DW

>C34–C40 hydrocarbons (mg/kg) = A>C34-C40  x  C36 conc  x  Volext  x  F  x   100

     AC36    W   %DW

where:
A>C10–C16 = the integration of all area counts from the end of the nC10 to the end of the nC16 peak
A>C16–C34 = the integration of all area counts from the end of the nC16 to the end of the nC34 peak
A>C34–C40 = the integration of all area counts from the end of the nC34 to the end of the nC40 peak
C14  = concentration of C14 standard (mg/litre)
C24  = concentration of C24 standard(mg/litre)
C36  = concentration of C36 standard (mg/litre)
Volext  = Final volume of sample extract (litre)
F  = Dilution factor applied to bring the samples and standards into appropriate peak height range
W  = weight of sample taken (kg)
% DW  = % Dry weight