Adding methane carbon isotopes as new species to the database.

[Mr.white]

Why can't 13C and 12C be recognized？
C1           C1    0      16.042        16.042 
C2           C2    0      30.068        30.068
C3           C3    0      44.094         44.094
13C1           13C1  0     17.035355     17.035355
12C1           12C1  0     16.042       16.042
ERROR: Reading element for master species.
ERROR:13C1           13C1  0     17.035355     17.035355
ERROR:12C1           12C1  0    16.042       16.042

[dlparkhurst]

Consider using the following definitions for your calculations. [C1], [C2], [C3] represent the 12C methane, ethane, and propane, which are defined as normal phreeqc concentratons. [13C1], [13C2], and [13C3] represent the 13C versions of methane, ethane, and propane, which are defined with permil definitions. At any point in your calculations, the ratios and permil values of the isotopes will be calculated.

You should be able to add these definitions in your input file for any database that you are using.

Code: [Select]

SOLUTION_MASTER_SPECIES
    [C1]          [C1]             0     12.0111              12.0111
    [C2]          [C2]             0     24.0222              24.0222             
    [C3]          [C3]             0     36.0333              36.0333     
    [13C1]        [13C1]             0     12.0111              12.0111
    [13C2]        [13C2]             0     24.0222              24.0222             
    [13C3]        [13C3]             0     36.0333              36.0333 
SOLUTION_SPECIES
   [C1] = [C1]
log_k 0
   [C2] = [C2]
log_k 0
   [C3] = [C3]
log_k 0
   [13C1] = [13C1]
log_k 0
   [13C2] = [13C2]
log_k 0
   [13C3] = [13C3]
log_k 0
ISOTOPES
[C1]       
     -isotope        [13C1]   permil  0.0111802             
[C2]       
     -isotope        [13C2]   permil  0.0111802   
[C3]       
     -isotope        [13C3]   permil  0.0111802         

ISOTOPE_RATIOS
R(13C)_C1(aq) [13C1]
R(13C)_C2(aq) [13C2]
R(13C)_C3(aq) [13C3]
CALCULATE_VALUES
R(13C)_C1(aq)
     -start
10 ratio = -9999.999
20 if (TOT("[C1]") <= 0) THEN GOTO 100
30 total_13C1 = TOT("[13C1]")
40 total_C1 = TOT("[C1]")
50 ratio = total_13C1/total_C1
100 save ratio
-end
R(13C)_C2(aq)
     -start
10 ratio = -9999.999
20 if (TOT("[C2]") <= 0) THEN GOTO 100
30 total_13C2 = TOT("[13C2]")
40 total_C2 = TOT("[C2]")
50 ratio = total_13C2/total_C2
100 save ratio
-end
R(13C)_C3(aq)
     -start
10 ratio = -9999.999
20 if (TOT("[C3]") <= 0) THEN GOTO 100
30 total_13C3 = TOT("[13C3]")
40 total_C3 = TOT("[C3]")
50 ratio = total_13C3/total_C3
100 save ratio
     -end
END
SOLUTION
[C1] 1
[13C1] 0
[C2] 1
[13C2] 10 permil
[C3] 1
[13C3] 20 permil
END
RUN_CELLS
-cell 1
END


[Mr.white]

thank you so much