HI 4107 CHLORIDE COMBINATION CHLORIDE HI 4007 Instruction Manual HI 4007 HI 4107 Half-cell Combination Chloride Ion Selective Electrode 1
HI 4007 Chloride Half-cell HI 4107 Chloride Combination Electrode I. Introduction: The Hanna HI 4007and HI 4107 are ion selective electrodes designed for the measurement of chloride ions in aqueous solutions. The HI 4007 is a solid state half-cell sensor that requires a separate reference. The HI 4107 is a combination ion selective electrode. IIII. Specifications Type: Solid State electrode with a Silver Chloride pellet. Chloride (Cl-) Ion(s) measured: 1.0 M to 5 X 10-5 M 35,500 to 1.
III. Theory of Operation Operation:: The HI 4007 or HI 4107 chloride electrodes are potentiometric devices used for the rapid determination of free chloride ions in ground water, boiler water and drinking water. The electrode functions as a sensor or ionic conductor. The HI 4007 requires a separate reference electrode to complete its electrolytic circuit. The HI 4107 has a reference electrode incorporated in its design.
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V. Equipment required: • Hanna HI 5315 Double Junction Reference Electrode with HI 7072 Fill Solution for HI 4007. • Hanna HI 4222 pH/ISE/mV meter or other suitable ion or pH/mV meter. (Note: log/linear graph paper is useful if an ISE (ion) meter is not available. • Hanna HI 180 Magnetic Stirrer or equivalent with Teflon coated stirring bars (HI 731320). (Note: isolate beakers from stirrer motor heat by placing insulating material such as foam or cork between them).
A user supplied oxidizing reagent may be used to supress interferences such as hydroxide, sulfide, bromide, ammonia or cyanide . Add 10 mL to 100 mL standard or sample. Permit sample to mix 10 minutes before measurements are taken. Discard samples and standards promptly as the chloride in these will oxidize upon standing making them unrelible. Do not permit electrodes to remain in this solution for long periods of time. Work in a hood and protect eyes and skin. Prepare oxidizing reagent by diluting 6.
• Avoid large changes in temperature (thermal shock) as it may damage the sensor. HI 4007 • Remove protective cover from sensor tip. • Prepare HI 5315 reference electrode by filling electrolyte reservoir with HI 7072 fill solution. • Place sensor and reference electrodes into electrode holder and connect cable connectors to meter. HI 4107 • Remove the protective plastic wrap that covers the ceramic junction before assembling sensor for the first time.
Deionized Water VIII. Electrode Preparation HI 4007 1. Remove protective cover from sensor tip. 2. Prepare reference electrode by filling outer electrolyte reservoir with HI 7072. 3. Place sensor and reference electrodes into electrode holder and connect cable connectors to meter. HI 4107 1. Unwrap plastic film seal found over ceramic junction on inner stem and discard. This is only used for shipping and long term storage. 2.
HI 4107 DE CHLORI ATION IN COMB 6. Holding the body of the electrode gently press upper cap with your thumb. This permits the fill solution to drain out of the body. Release cap and verify electrode returns to its original position. (You may need to gently assist for this to occur). 7. Tighten the electrode cap onto the body and fill electrode body until fill solution volume is just below fill hole. 8. Position electrode in a Hanna HI 76404 electrode holder (or equivalent) and connect plug to meter.
IX. • • • • • • • Quick Check of Electrode Slope Connect sensors to pH/mV/ISE meter Place meter in mV mode. Place 100 mL of DIW into a beaker with stir bar. Place reference and measuring half-cell into prepared sample. Add 1 mL of a standard (0.1 M or 1000 ppm standard) to beaker. Record the mV value when stable. Add an additional 10-mL of standard to the solution. Record the mV when reading has stabilized. This value should be less than the previous noted (more negative).
• • If dark deposits appears on polishing strip move the paper slightly and continue polishing. If the sensor slope just misses the suggested slope window, soaking the sensor in a standard may solve the problem. If the membrane is damaged, the response becomes extremely sluggish, or the slope of the electrode has decreased significantly, and procedures above have not helped, the sensor should be replaced. XI. Direct Calibration and Measurement This method is a simple procedure for measuring many samples.
Procedure Follow sections VIII and IX to prepare sensors for measurement. Follow section VI to prepare standards/ solution. Standards should bracket and fall within the range of interest. Two mL HI 4000-00 ISA, or 10 mL acetate pH buffer or 10 mL of oxidizing reagent is added to 100 mL of both samples and standards. Add stir bar and mix before taking measurements. Measurements using the oxidizing reagent must be made 10 minutes after mixing and not permitted react longer.
XII. Other Measurement TTechniques echniques Known Addition (for Cl ) An unknown concentration can be determined by adding a known amount (volume and concentration) of measured ion to a known volume of the sample. This technique is called Known Addition. The method can use an ideal sensor slope, but actual determined slopes at the temperature of measurement should be used if known. This method is preprogrammed in the Hanna HI 4222 pH/ISE/mV meter, which simplifies the method greatly.
Titration A chloride electrode may be used as an indicator to follow the progress of a chloride tiration with silver nitrate. The electrode can be used in colored samples where other indicators suffer from interferences. During the titration the sensor follows the decrease in chloride concentration while small additions of silver nitate titrant are added. The silver reacts with the chloride ions forming a precipitate of silver chloride. At the stoichiometric end point, a large change in mV occurs.
XV. Conversion tables For Cl- Multiply by Moles/L (M) to ppm (mg/L) ppm (mg/L) to M (moles/L) 3.500 x 104 2.
MAN4107 05/08 WARRANTY Hanna Instruments Ion Selective Electrodes are warranted to be free of defects in material and workmanship for 6 months from date of purchase when used for their intended purpose and maintained according to instructions. If they fail to work when first used contact your dealer immediately. Damage due to accidents, misuse, misapplication, tampering or lack of prescribed maintenance is not covered.
