Preparation of low standard solutions calculate the

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Preparation of Low Standard Solutions (calculate the true ppm) Use separate 50-mL volumetric flasks to prepare 0, ~1.0, ~2.0 and ~3.0 ppm standardsolutions for the calibration curve. Table 1 is used for volumes of working and reducingsolutions. Use a pipet for multiple times as you need. The flasks should be diluted to themark (where applicable) and mixed, and then 5-10 mL is transferred to test-tubes. Label thetest-tubes.Table 1. Volumes of Reducing and WorkingSolutions to be used for ppm P2O5(estimated)~0~1.0~2.0~3.0*Volume of Reducing Solution(mL)20.0020.0020.0020.00Volume of Working Solution(mL)010.0020.0030.00* will not need to be diluted to the mark.Step 2: A does the following:Preparation of Standard Solutions for Dynamic Range from 0 to 10 ppm (calculate thetrue ppm)Use separate 50-mL volumetric flasks to prepare ~4.0, ~6.0, ~8.0, and ~10.0 ppm samplesolutions. Table 2 is used for volumes of intermediate standard and reducing solution. Theflasks should be diluted to the mark and mixed, and then 5-10 mL is transferred to test-tubes. Table 2. Volume of Reducing and IntermediateStandard solution to be used.Volume of Reducing Solution (mL)20.0020.0020.0020.00Volume of Intermediate Standard(mL)4.006.008.0010.00Estimated ppm P2O5~4.0~6.0~8.0~10.03
B does the following:Preparation of Phosphoric Acid Containing Samples (Read the Label)Using a volumetric pipet, pipet 3 mL of the degassedsample into a 50-mL volumetric flask.Dilute the flask to the mark and mix. Using a volumetric pipet, pipet 3 mL ofthat dilutedsampleinto another 50-mL volumetric flask. Add 20 mL of the reducing solution. Dilute thecontents of flask to the mark, mix and then 5-10 mL is transferred to a test-tube. Don’t forgetto keep the original sample as well.Step 3A does the following:Preparation of Non-Phosphoric Acid Containing Samples (Read the Label)Using a volumetric pipet, pipet 5 mLof the degassedsample into a 50-mL volumetric flask.Add 20 mL of the reducing solution. Dilute the flask contents to the mark, mix and transfersome to a test-tube. Don’t forget to keep the original sample as well.Both A and B:Place all solutions in test-tubes at the same time into the water bath.Preparation of Solutions and Samples

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