How to use instrument-specific information
The Instrument-specific information table displays requirements that may vary between instruments. To use this table, select an instrument then read across to find the corresponding information required to perform this test.
Chloride
DOC316.53.01017
Mercuric Thiocyanate Method
Method 8113
(0.1 to 25.0 mg/L Cl
–)
Scope and Application: For water and wastewater
Test preparation
Table 1 Instrument-specific information
Instrument Sample cell Cell orientation Adapter
DR 5000 2495402 Fill line faces user A23618
DR 2800 2495402 Fill line faces right —
DR 2700 2495402 Fill line faces right —
DR/2500 2427606 — —
DR/2400 2427606 — —
Before starting the test:
Filter turbid samples with moderately rapid filter paper and a funnel before analysis.
Both the sample and the blank will contain mercury (D009) at a concentration regulated as a hazardous waste by the Federal RCRA. Do not pour these solutions down the drain.
Refer to the MSDS sheet for safe handling and disposal of hazardous waste. Gloves are recommended.
Collect the following items:
Description Quantity
Ferric Ion Solution 1 mL
Mercuric Thiocyanate Solution 2 mL
Deionized Water 10 mL
Sample Cells (see Instrument-specific information) 2
Pipet, TenSette®, 0.1 to 1.0 mL 1
Pipet tips for 0.1 to 1.0 mL TenSette pipet 2
Mercuric Thiocyanate method for Chloride
1. Select the test. Insert an adapter if required ( Instrument-specific information). Refer to the user manual for orientation.
2. Prepared Sample: Fill a sample cell with 10 mL of sample.
3. Blank Preparation: Fill another sample cell with 10 mL of deionized water.
4. Pipet 0.8 mL of Mercuric Thiocyanate Solution into each sample cell.
5. Swirl to mix. 6. Pipet 0.4 mL of Ferric Ion Solution into each sample cell.
7. Swirl to mix. An orange color will develop if chloride is present.
8. Start the instrument timer.
A two-minute reaction time will begin.
9. Within five minutes after the timer expires, wipe the blank and insert it into the cell holder.
10. ZERO the instrument. The display will show:
0.0 mg/L Cl–
11. Wipe the prepared sample and insert it into the cell holder.
12. READ the results in mg/L Cl–.
70 Chloride
Stored Programs
Start
Interferences
Sample collection, preservation and storage
Collect samples in glass or plastic containers. Samples can be stored for at least 28 days at room temperature.
Accuracy check
Required for accuracy check:
• Chloride Standard Solution, 1000-mg/L • 50 mL mixing cylinders, three
• TenSette Pipet
Standard additions method (sample spike)
1. After reading test results, leave the sample cell (unspiked sample) in the instrument. 2. Select standard additions from the instrument menu:
3. Default values for standard concentration, sample volume, and spike volumes can be
accepted or edited. After values are accepted, the unspiked sample reading will appear in the top row. See the user manual for more information.
4. Prepare three sample spikes. Fill three 50 mL mixing cylinders with 50 mL of sample. Use the TenSette® Pipet to add 0.1 mL, 0.2 mL and 0.3 mL of 1000-mg/L Chloride Standard Solution,
respectively, to the cylinders and mix each thoroughly.
5. Analyze a 10 mL portion of each sample spike as described in the Mercuric Thiocyanate method for Chloride test, starting with the 0.1 mL sample spike. Each addition should reflect approximately 100% recovery.
6. Select GRAPH to view the results. Select IDEAL LINE (or best-fit) to compare the standard addition results to the theoretical 100% recovery.
Table 2 Interfering substances and levels
Interfering substance Interference levels and treatments
Extreme pH
Should be about pH 2 after adding reagents.
If the sample is strongly acidic or alkaline, adjust a portion of sample before testing to a pH of about 7. Use either 5.0 N Sodium Hydroxide Standard Solution1 or a 1:5 dilution of perchloric acid. Use pH paper; most pH electrodes will contaminate the sample with chloride.
1 See Optional reagents and apparatus.
Instrument Navigate to:
DR 5000 OPTIONS>MORE>STANDARD ADDITIONS
DR 2800 OPTIONS>MORE>STANDARD ADDITIONS
DR 2700 OPTIONS>MORE>STANDARD ADDITIONS
DR/2500 OPTIONS>STANDARD ADDITIONS
Standard Solution Method Required for accuracy check:
• Chloride Standard Solution, 1000-mg/L • Volumetric Flask, 500-mL
• Pipet, Class A glassware
1. Prepare a 20.0-mg/L chloride standard solution.
a. Use Class A glassware to pipet 10.00 mL of Chloride Standard Solution, 1000-mg/L, into a 500-mL volumetric flask.
b. Dilute to the mark with deionized water. Follow the Mercuric Thiocyanate method for Chloride test.
2. To adjust the calibration curve using the reading obtained with the standard solution, navigate to Standard Adjust in the software.
3. Turn on the Standard Adjust feature and accept the displayed concentration. If an alternate concentration is used, enter the concentration and adjust the curve to that value.
Method performance
Instrument Navigate to:
DR 5000 OPTIONS>MORE>STANDARD ADJUST
DR 2800 OPTIONS>MORE>STANDARD ADJUST
DR 2700 OPTIONS>MORE>STANDARD ADJUST
DR/2500 OPTIONS>STANDARD ADJUST
DR/2400 OPTIONS>STANDARD ADJUST
Program Instrument Standard Precision
95% Confidence Limits of Distribution
70 DR 5000 20.0 mg/L Cl– 17.9–22.1 mg/L Cl–
DR 2800 20.0 mg/L Cl– 17.9–22.1 mg/L Cl–
DR 2700 20.0 mg/L Cl– 17.9–22.1 mg/L Cl–
DR/2500 20.0 mg/L Cl– 18.3–21.8 mg/L Cl–
DR/2400 20.0 mg/L Cl– 18.3–21.8 mg/L Cl–
Program Instrument Standard Portion of curve
Sensitivity Concentration change
per 0.010 Abs change
70 DR 5000 DR 2800 DR 2700 20.0 mg/L Cl– 1.0 mg/L 0.1 mg/L Cl– 10.0 mg/L 0.3 mg/L Cl– 20.0 mg/L 0.6 mg/L Cl– DR/2500 DR/2400 20.0 mg/L Cl– 1.0 mg/L 0.11 mg/L Cl– 20.0 mg/L 45 mg/L Cl–
Summary of method
Chloride in the sample reacts with mercuric thiocyanate to form mercuric chloride and liberate thiocyanate ion. Thiocyanate ions react with the ferric ions to form an orange ferric thiocyanate complex. The amount of this complex is proportional to the chloride concentration. Test results are measured at 455 nm.
Consumables and replacement items
Required reagentsDescription Quantity/Test Unit Catalog number
Chloride Reagent Set, includes: — 100 tests/pkg1
1 100 tests (50 samples and 50 blanks) using 10-mL cells. 50 tests using 25-mL cells.
2319800
(1) Ferric Ion Solution 1 mL 100 mL 2212242
(1) Mercuric Thiocyanate Solution 2 mL 200 mL 2212129
Water, deionized 10 mL 4 L 27256
Required apparatus
Description Quantity/Test Unit Catalog number
Pipet, TenSette®, 0.1 to 1.0 mL 1 each 1970001
Pipet Tips, for TenSette Pipet 1970001 varies 50/pkg 2185696
Recommended standards
Description Unit Catalog number
Chloride Standard Solution, 1000-mg/L Cl– 500 mL 18349
Optional reagents and apparatus
Description Unit Catalog number
Chloride Standard Solution, 10-mL Voluette® Ampule, 12,500-mg/L Cl– 16/pkg 1425010
Chloride Standard Solution, 100-mg/L 1 L 2370853
Cylinders, mixing 50 mL 189641
Filter Paper, funnel 100/pkg 69257
Funnel, poly 75 mm 108368
Gloves, chemical resistant, size 9–9.51 pair 2410104
Perchloric Acid, ACS 680 g 75765
pH Paper, 1.0–11.0 pH range 5/pkg 39133
Pipet Tips, for TenSette Pipet 1970001 1000/pkg 2185628
Pipet, volumetric, Class A 10 mL 1451538
Pipet Filler, safety bulb each 1465100
Sodium Hydroxide Standard Solution, 5.0 N 50 mL 245026
