TDS(Total Dissolved

Solids)By

EPA 160.1 & 2540cKarley NeilsonEng. 2100August 07, 2015

SummaryAn initial weight of a porcelain crucible is taken. A well-

mixed portion of sample is filtered through a standard glass-fiber filter using a vacuum pump, and filter flask. The filtrate is evaporated and dried to constant weight at 180 ◦C oven. A final weight is taken. The increase in dish weight represents the total dissolved solids.

• For every 10 samples a duplicate of that sample needs to be made.• For every 20 samples an extra set of QCs need to be added.

• Vacuum pump• 500mL vacuum filtration flasks, acid-

washed• Glass-fiber filter disks• Porcelain 100mL crucibles• Graduated cylinders and volumetric

pipettes, class A• Wash bottle• Tongs • Desiccator • Oven (Capable of maintain 180 degrees C)

EquipmentPump

Flask Crucible Cylinde

rs

Oven Desiccator

Tongs Filters

Quality Control Samples(LMB, LCS, LCSD)

• LMB: Is the Matrix/Media Blank (Target 0, +/- 10)• The is where we try and match the clients media they send us to be

analyzed. For this method that would be a glass fiber filter.

• LCS: Is the quality controlled sample (Target 100, +/- 10)• This sample is spiked with a known standard that is prepared.

• LCSD: This is a duplicate of the LCS (Target 100, +/- 10)• This is to double check that we have a accurate standard.

This standard is made in a 2 L flask. The standard calls for .1 g per liter; since we use a larger flask we need to double the weight. For this standard we will use .2 g and then bring to volume with ASTTM Type 3 water (DI water). We then will measure out 50 mL and pour them into its designated crucible. Our system is automatically set up to calculate the results.

• The standard is made of a powder that is made up of various dirt's and minerals. We order this standard from RICCA on of our venders.

Standard

Step 1

• Place Crucibles into the oven set at a temperature of 180◦C, and let them cook for 1 hr. Remove from oven and place in desiccator for at least 2 hours to ensure that all heat has left the crucible.• Porcelain crucibles hold heat longer than other materials, such as,

glass or metal.

Oven Desiccator

Step 2

• Once crucibles have been cooled it is time to get an initial weight on them. To do this we are going to assign our crucibles numbers. Number will depend on how many samples are batched and also the three QCs (quality control samples). We are going to use a balance and record our data. Write the initial weight next to the correct sample, and repeat for each one, including QCs.

Electronic balance

Step 3

• Now that you have you initial weights its time to start the prepping/analyst. You are going to need to set up your bump and fill your water bottle with ASTTM Type 3 Water. Once you have your flask set up to your pump you are ready to start. Take your samples and measure out 100 mL with your graduated cylinder. Do this for each sample in order of how you have them batched.• You will only need 50 mL for the actual analyst, but a 100 mL is

taken for duplicate samples.

Step 4After you have filtered all of the samples it is time to transfer

them into their designated crucible. Remember to make sure you are keeping the samples in the proper order.

• First: is your LMB which is considered your Blank. QC is a matric of which matches the clients media (glass fiber filter) and ASTTM Type 3 water (50mL).

• Second: your LCS and LCSD, these are poured from your standard you made in the 2 L flask. This will consist of the .2 g/L of the powder.

• Third: 50 mL of your sample will be measure out using the graduated cylinder, and poured into the crucible.

Step 5

• The QCs and samples are placed in the oven at 180◦C where they will need to cook over night (8hours+). Once the samples have finished in the oven they will need to be placed in the desiccator for at least 2 hours.

Step 6• After they have cooled for the appropriate amount of time, we then

proceed to take the final weight. This is done on the same balance as the initial weights. The final volume will need to be document next to the initial. The system already calculate the results for your using this equation. mg/L = (A – B) x 1,000,000

C• Remember to double check to make sure your QCs are in

range.

• This is a basic break down of the 160.1/2540c SOP. This PowerPoint will help give employees/readers a visual on the method and what to look for when performing this analyst. This SOP is broken down step by step; this should help keep your work organized and efficient.

Conclusion