craigbingman
Community Member
What is the wavelength range of your instrument? Cl- is easily quantitated if your machine goes into the deep UV. I would personally measure F- with an ion-selective electrode rather than HPLC.
Calculation of salinity from Triton ICP-OES test results
- Thread starter JimWelsh
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What is the wavelength range of your instrument? Cl- is easily quantitated if your machine goes into the deep UV. I would personally measure F- with an ion-selective electrode rather than HPLC.
OP
OP
I just noticed that the change in forum software totally messed up the tables in my earlier posts in this thread (bummer), and also removed the link to the spreadsheet. I'm attempting to re-link the spreadsheet here.
loui
Valuable Member
not sure if this is still being looked at, but I got my results today and I am really interested in what they are reading as my salinity. I got 10854.00 mg/l. I checked out your spreadsheet, but I can't edit because I don't have the full version of excel only the viewer. If someone could do the conversion for me that would be great. According to them I am over 154 from there set point of 10700.00, which I am assuming that I am pretty close to being right on the money and is close enough for me. btw if anyone is interested I try to maintain my salinity at 1.026.
OP
OP
Based on your Triton test results, the salinity was 34.28. After raising the Ca to 426, and assuming you used CaCl2 to do so, with no other changes, the salinity would have gone up to 34.47.
Lazys Coral House
Well-Known Member
Does anyone still have the link to the excel spreadsheet that someone here put together to calculate the salinity of triton test? Thanks
OP
OP
Lazys Coral House
Well-Known Member
Thank you!
bernard92
New Member
Working myself to estimate the Salinity using my Triton Lab test I found your excel sheet for it. After comparing the results to reassure me about what I made with your Excel sheet (thank you for sharing it, it's very usefull), I have some questions:
You started with B(OH)3 into the sheet but your didn’t used it at the end (what is the reason ? mistake into the Sum() ?). Why do not use B(OH)4- also. Both have impacts in the real seawater for 19.8 mg/kg and 7.9 mg/kg (we can keep the same proportion for example and use the B measures). It’s not some much but why not using it (it’s the last part using the measures that we may add)?
Do you have any reference for the formula used for the Alkanity (what are the Anions used for example)? I used myself a constant value but your formula seems more accurate as for a reef tank with the distinct values of KH that we can have into a reef tank.
I have another question: why using 25°C? Can we assume that Triton results (ml/l) are provided ‘for’ 25°C?
FYI(yoy may or not already know it): I made some extra checks using the TEOS-10 API for the density (for the density used to convert mg/l to mg/kg + iterate several times between Salinity and Density for ‘stable’ result at the end) and I found a difference for the Salinity between 0.04 and 0.07 depending of the inputs used. This confirms that using a simpler formula for the density may still enough accurate for the objective (I wanted to ‘see’ it by myself).
You started with B(OH)3 into the sheet but your didn’t used it at the end (what is the reason ? mistake into the Sum() ?). Why do not use B(OH)4- also. Both have impacts in the real seawater for 19.8 mg/kg and 7.9 mg/kg (we can keep the same proportion for example and use the B measures). It’s not some much but why not using it (it’s the last part using the measures that we may add)?
Do you have any reference for the formula used for the Alkanity (what are the Anions used for example)? I used myself a constant value but your formula seems more accurate as for a reef tank with the distinct values of KH that we can have into a reef tank.
I have another question: why using 25°C? Can we assume that Triton results (ml/l) are provided ‘for’ 25°C?
FYI(yoy may or not already know it): I made some extra checks using the TEOS-10 API for the density (for the density used to convert mg/l to mg/kg + iterate several times between Salinity and Density for ‘stable’ result at the end) and I found a difference for the Salinity between 0.04 and 0.07 depending of the inputs used. This confirms that using a simpler formula for the density may still enough accurate for the objective (I wanted to ‘see’ it by myself).
OP
OP
Regarding B(OH)3, I used it as undisassociated because that's what Pilson did. However, you are correct that I accidentally failed to include it in the sum formula in cell I13 -- thank you for catching that! Good thing it only makes a difference of around 0.02! I'll have to fix that and post the revision.
The alkalinity formula is derived from the sum of the carbonate, bicarbonate, and hydroxide anions shown for a pH of 8.2 at various temperatures by the CO2Sys spreadsheet that can be found here: http://cdiac.ornl.gov/ftp/co2sys/CO2SYS_calc_XLS_v2.1/. I was really just having fun with the math on that one; a constant value or simpler assumptions could be used instead.
Note that the temperature is not fixed at 25C; you can set it to whatever you want, and I realize that while it is confusing, you are correct that I mean it to be the temperature at which Triton is reporting the results, since they are reporting in mg/L instead of mg/kg, the temperature makes a difference, but Triton doesn't state the temperature.
Yes, I am aware of the problem with the density calculation. I use the density of NSW at S=35 for the density factor, because it is not possible to use the actual salinity of the sample for the density conversion due to a "circular reference" problem. Of course, you are correct, an iterative approach solves that problem, but is difficult to implement in a simple spreadsheet such as this one.
Thank you for taking the time to go over my spreadsheet in so much detail, and I appreciate the feedback and comments. Good work!
The alkalinity formula is derived from the sum of the carbonate, bicarbonate, and hydroxide anions shown for a pH of 8.2 at various temperatures by the CO2Sys spreadsheet that can be found here: http://cdiac.ornl.gov/ftp/co2sys/CO2SYS_calc_XLS_v2.1/. I was really just having fun with the math on that one; a constant value or simpler assumptions could be used instead.
Note that the temperature is not fixed at 25C; you can set it to whatever you want, and I realize that while it is confusing, you are correct that I mean it to be the temperature at which Triton is reporting the results, since they are reporting in mg/L instead of mg/kg, the temperature makes a difference, but Triton doesn't state the temperature.
Yes, I am aware of the problem with the density calculation. I use the density of NSW at S=35 for the density factor, because it is not possible to use the actual salinity of the sample for the density conversion due to a "circular reference" problem. Of course, you are correct, an iterative approach solves that problem, but is difficult to implement in a simple spreadsheet such as this one.
Thank you for taking the time to go over my spreadsheet in so much detail, and I appreciate the feedback and comments. Good work!
bernard92
New Member
I had feedback from Triton lab: they recommend to use 20°C.
I added a user interface to the script I made: http://monrecifamoi.saulme.fr/salinite/elements_compute_salinity.php .You have optional assumptions. Triton lab export csv file can be used as input
Setting 'T=25', 'B(OH)3' & 'NSW at S=35' you have the same result as your excel file (the small differences are due to the rounded molar mass used for F and SO4).
I added a user interface to the script I made: http://monrecifamoi.saulme.fr/salinite/elements_compute_salinity.php .You have optional assumptions. Triton lab export csv file can be used as input
Setting 'T=25', 'B(OH)3' & 'NSW at S=35' you have the same result as your excel file (the small differences are due to the rounded molar mass used for F and SO4).
drawman
2500 Club Member
@JimWelsh and @bernard92 thanks for your work on this thread. Just ran my Triton numbers and my salinity is definitely high. I've been calibrating my refractometer regularly with calibration solution so I'm surprised to see it.
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