User manual HANNA INSTRUMENTS HI 902

[. . . ] INSTRUCTION MANUAL HI 901 / HI 902 AUTOMATIC TITRATOR 2003 Nov 12, 15:44:31 rant NaOH Tit Conc. N (eq/L) 0 RPM 1300/130 0. 000 Standard No Result trode ize Elec Volume Endpoint Select Method Method Options Burette pH pH/mV NaOH 0. 1 M ATC General Options TABLE O. INTRODUCTION SETUP USER INTER. ACE GENERAL OPTIONS METHODS TITRATION MODE pH & mV MODE AUXILIARY . UNCTIONS MAINTENANCE, PERIPHERALS Appendix 1. BACK TITRATION (HI 902 only) Appendix 3. [. . . ] Example: g > mol 5-33 METHODS 5. 5. 11. 2 Back Titrations (HI 902 only) Sample Calculations by Weight When choosing this formula, select the titrant 1 unit, the titrant 2 unit and then the final result unit. 5-34 METHODS If the titrant 1 unit is selected as M (mol/L), titrant 2 unit is selected as M (mol/L) and the final result unit as mg/g (milligrams/gram) the following formula is used to calculate the amount of titrant 1 (used in the first stage of back titration or direct titration) and will be as follows: The formula is based on an approximation: the sample concentration is 100% w/w. With this approximation, the titrator will calculate the volume of titrant 1 needed to consume the sample and multiply it with an excess factor in order to raise or to lower the amount of titrant 1 dispensed. Some variables can be set according to the amount of sample and titrant 1 used. When the parameters from the formula are set, press to proceed with the next formula used in the back titration algorithm. Volume formula, then from the View / Modify Method screen: highlight the Titrant 1 Entry option, press . highlight . ixed Weight or Volume option and press , you will be prompted to type the volume of titrant 1 to be dispensed in the first stage of back titration. This formula is used to calculate the remaining volume of titrant 1 after the reaction with the sample. 5-35 METHODS In order to calculate this volume, the remaining titrant 1 volume is titrated (pH/mV equivalence point titration) with titrant 2. After the excess volume of titrant 1 is calculated, the following formula is used to calculate the exact volume of titrant 1 that was consumed by the sample: V1 = V1tot V1excess When all the parameters are set, press Concentration formula: to proceed with the Calculating Sample Sample Calculations by Volume When choosing formula, follow these steps: . irst select the titrant 1 unit 5-36 METHODS Select the titrant 2 unit Select the final result unit The titrator will provide the calculation based on the titrants and sample units selected. After you have selected the titrant 1, titrant 2 and the final result units the titrator will display a screen with a formula used to calculate the amount of titrant 1 (used in the first stage of back titration). 5-37 METHODS This calculation formula is used as an approximation of the sample concentration (sample max conc. ). This formula can be used when we have an expected sample concentration (eg. we know that the sample concentration must be around 1 M (mol/L)). If we dont have an expected sample concentration, then from the View/Modify Method screen: . highlight the Titrant 1 Entry option, by pressing highlight . ixed By User option and press , you will be prompted to type the volume of titrant 1 to be dispensed in the first stage of the back titration. With this approximation, the titrator will calculate the volume of titrant 1 needed to consume the sample and multiply it by an excess factor in order to raise or to lower the amount of titrant 1 dispensed. When the parameters from the formula are set, press to proceed to the next formula used in the back titration algorithm. This formula is used to calculate the remaining volume of titrant 1 after the reaction with the sample. In order to calculate this volume, the remaining volume of titrant 1 is titrated (pH/mV equivalence point titration) with the titrant 2. After the excess (remaining) volume of titrant 1 is calculated, the following formula is used to calculate the exact volume of titrant 1 that was consumed by the sample: V1 = V1tot V1excess 5-38 METHODS When all the parameters are set, press Concentration formula: to proceed with the Calculating Sample Generic . ormula This option allows the user to define their calculation formula for the Direct Titration Volume, Calculating Excess Volume of Titrant 1 and . inal Sample Concentration in a solid or liquid sample. 5. 5. 12 Dilution Option This option enables the dilution calculations to be made (when the initial sample is diluted, the titration is made with an aliquot of the diluted sample). The calculations are made for the sample weight (volume) in order to express the results for the initial sample. . inal Dilution Volume: The volume of the sample after the dilution process. Aliquot Volume: The volume of the aliquot (sample volume used for the titration) Analyte size to be diluted: The initial sample weight (volume) 5-39 METHODS The sample size used in the calculations will be: Analyte size to be diluted * Aliquot Volume . inal Dilution Volume 5. 5. 13 Titrant Name Enter the name of the titrant (up to 24 characters). This name will appear in the titration report. 5. 5. 14 Titrant Concentration Enter the concentration of the titrant to be used. When determining the titrant concentration only the unit is displayed and the titrant concentration can not be set. 5. 5. 15 Analyte Size Enter the size of the sample (for sample concentration determinations) or standard (for titrant concentration determination). 5. 5. 16 Analyte Entry With this option select the entry type mode of the analyte. 5-40 METHODS 5. 5. 16. 1 . ixed Weight or Volume Each titration will use the same analyte weight or volume as preset in the calculations. 5. 5. 16. 2 Manual Weight or Volume Each titration will use a different analyte weight or volume. [. . . ] HI 1131B / HI 1111S Glass-body, single junction, refillable, combination pH electrode. HI 1330B / HI 1310S Glass-body, semimicro, single junction, refillable, combination pH electrode. HI 1331B / HI 1311S Glass-body, semimicro, single junction, refillable, combination pH electrode. HI 1230B / HI 1210S Plastic-body (Ultem®), double junction, gel-filled, combination pH electrode. [. . . ]