commonaskedquestions_ise
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| =====Frequently Asked Questions (Ion-selective electrodes)===== | =====Frequently Asked Questions (Ion-selective electrodes)===== | ||
| - | ===How often do you need to calibrate? | + | ====How often do you need to calibrate?==== |
| - | Recalibrate | + | Calibrate |
| - | ===How long after being opened or made are standards good?=== | + | ====How long after being opened or made are standards good?==== |
| The stock standard will last at least six months before discarding, whereas diluted standards treated with ISA/pH buffer should be prepared weekly. | The stock standard will last at least six months before discarding, whereas diluted standards treated with ISA/pH buffer should be prepared weekly. | ||
| - | ===How do you store the electrodes? | + | ====How do you store the electrodes?==== |
| It is best to store them dry when they are not to be used in the next week or so. Empty out the filling solution in the gas-sensing electrode. For shorter periods, store in dilute standard approximating the sample concentration, | It is best to store them dry when they are not to be used in the next week or so. Empty out the filling solution in the gas-sensing electrode. For shorter periods, store in dilute standard approximating the sample concentration, | ||
| - | ===Can you do temperature compensation with ISE?=== | + | ====Can you do temperature compensation with ISE?==== |
| Yes, it is possible, but somewhat difficult. | Yes, it is possible, but somewhat difficult. | ||
| - You have to know the isopotential point for a given electrode system. | - You have to know the isopotential point for a given electrode system. | ||
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| - Very little isopotential point data for ISE's is available at this time. | - Very little isopotential point data for ISE's is available at this time. | ||
| **It is best to standardize and measure samples at the same temperature without using temperature compensation.** | **It is best to standardize and measure samples at the same temperature without using temperature compensation.** | ||
| - | ===Can you do in-line continuous ISE measurement without treating the sample?=== | + | ====Can you do in-line continuous ISE measurement without treating the sample?==== |
| Yes, direct measurement is possible in many cases without ISA/buffer addition to the sample stream. However, Fluoride, Sulfide, Ammonia, and Sodium Electrodes do require pH adjustment and must have ISA/ buffer added to the sample stream. | Yes, direct measurement is possible in many cases without ISA/buffer addition to the sample stream. However, Fluoride, Sulfide, Ammonia, and Sodium Electrodes do require pH adjustment and must have ISA/ buffer added to the sample stream. | ||
| - | ===Which standards should be used with the ISE?=== | + | ====Which standards should be used with the ISE?==== |
| The most obvious choice will be determined by what | The most obvious choice will be determined by what | ||
| concentration units are desired (e.g. ppm as what?). Also, if | concentration units are desired (e.g. ppm as what?). Also, if | ||
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| sulfate with a lead electrode), use a stock standard of the | sulfate with a lead electrode), use a stock standard of the | ||
| ion to be measured (e.g. sulfate). | ion to be measured (e.g. sulfate). | ||
| - | ===Why buy a combination electrode instead of separate ones?=== | + | ====Why buy a combination electrode instead of separate ones?==== |
| Advantages: | Advantages: | ||
| * no external reference electrode needed | * no external reference electrode needed | ||
commonaskedquestions_ise.txt · Last modified: 22/02/2019 10:55 by pieter
