User manual EUTECH INSTRUMENTS BROMIDE EPOXY

[. . . ] Instruction Manual Bromide Electrode EUTECH INSTRUMENTS PTE LTD. INSTRUCTION MANUAL BROMIDE ION ELECTRODE 1 Instruction Manual Bromide Electrode TABLE OF CONTENTS GENERAL INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Required Solutions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 GENERAL PREPARATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Electrode Preparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Electrode Slope Check (with a pH/mV meter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Electrode Slope Check (with an ion meter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 MEASUREMENT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Measuring Hints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Sample Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Units of Measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 MEASUREMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] Adjust the meter to the concentration of the standard and fix the value in the memory according to the meter manufacturer's instructions after stabilization of the reading. For low level bromide measurements, place the rinsed, dried electrodes into a solution containing 100 ml of distilled water and 2 ml of ISA. After stabilization, fix the blank value into the meter according to the meter manufacturer's instructions. Place 100 ml of the sample and 2 ml of ISA in a 150 ml beaker, place it on the magnetic stirrer, an d begin stirring. Immerse the electrode tips in the solution and wait for the reading to stabilize. Read the concentration directly from the meter display. The calibration should be checked every two hours. Assuming no change in ambient temperature, place the electrode tips in the first bromide standard. After the reading has stabilized, compare it to the original reading in Step 3 above. A reading differing by more than 0. 5 mV or a change in the ambient temperature will necessitate the repetition of steps 2-6 above. The meter should be re-calibrated daily. 4. 5. 6. 7. 8. 9. 10. Low Level Bromide Determinations (using a pH/mV meter) This procedure is recommended for solutions containing less than 2. 0X10-6M (0. 2 ppm). Use the following low level bromide measurement procedure in the non-linear portion of the calibration curve. Using 20 ml of the standard ISA, dilute to 100 ml with distilled water. This low level (1. 0M NaNO3) is added at the rate of 1 ml low level ISA to each 100 ml of sample. The background ionic strength will be 1. 0X10-2M. Dilute 1 ml of 0. 1M standard to 1, 000 ml to prepare a 1. 0X10-4M standard solution for measurements in moles per liter. Dilute 10 ml of 1, 000 ppm standard to 1, 000 ml to prepare a 10 ppm standard solution for measurements in ppm. Add 100 ml of distilled water to a 150 ml beaker. Add 1 ml of low level ISA, place the beaker on the magnetic stirrer, and begin stirring at a constant rate. 2. 3. 8 Instruction Manual Bromide Electrode 4. Place the rinsed, dried electrode tips in the solution and assure that the meter is in the mV mode. Add increments of the 1. 0X10-4M or 10 ppm standard as given in Table 2 below. After the reading has stabilized, record the mV reading after each addition. [. . . ] The composition of the liquid junction filling solution in the reference electrode is most important. The speed with which the positive and negative ions in the filling solution diffuse into the sample should be equitransferent. No junction potential can result if the rate at which positive and negative charge carried into the sample is equal. Strongly acidic (pH = 0-2) and strongly basic (pH = 12-14) solutions are particularly troublesome to measure. [. . . ]