Tube Tests

Water and waste water analysis is portable, safe, fast and accurate with AQUANALTM-Tube Tests in ready-to-read cuvettes for Chemical Oxygen Demand (COD) using dichromate digestion, TN (total nitrogen), ammonia, nitrite, nitrate, TP (total phosphorous) and orthophosphate. They are ideal for laboratory and field use, like sewage treatment plants. We also offer AQUANALTM-plus Heating Unit and AQUANALTM spectrophotometers to read the tubes.

COD (Chemical Oxygen Demand)

TN (Total Nitrogen)

TP (Total Phosphorous)

Ordering information
COD tube tests
Decomposition of organic compounds in water depletes dissolved oxygen and significantly affects water quality and health of aquatic biota. Chemical Oxygen Demand (COD) is a method to indirectly measure the amount of organic compounds in water. COD is expressed in milligrams per liter (mg/L), which indicates the mass of oxygen consumed per liter of solution.

AQUANALTM-COD cuvette tests provide fast, accurate and economical COD measurements for laboratory and field use. AQUANALTM-COD tubes contain potassium dichromate, which oxidizes the organic compounds, and mercury sulfate in sulfuric acid. Simply add the water sample (volume given in the test instructions) to the AQUANALTM-COD cuvette, digest at 150 °C for two hours and then read the results directly on a spectrophotometer. Results can be read using the AQUANALTM-plus SPECTRO 2, AQUANALTM-SPECTRO 3, AQUANALTM-plus SPECTRO CSB/COD or the AQUANALTM-professional SPECTRO 1000 photometers. The AQUANALTM-plus Thermoblock can be used to heat the samples.

If you currently use the micro-COD digestion method (by Sealed Digestion and Spectrometry), the AQUANALTM-COD tube tests provide equivalent results and use the same calibration curves as the vials that you currently use, required no method modification! Vials are packaged in spectrally uniform 16mm glass cells that fit directly in all commercially available COD reactors and spectrophotometers. AQUANALTM-COD tube tests will read directly on HACH spectrophotometers without any method adjustments.

Chloride (Cl-) is the primary interference when measuring COD. Samples with high chloride concentrations should be diluted prior to analysis. However, if sample dilution causes the COD levels to be too low for accurate determination, add 0.50 g of mercuric sulfate (HgSO4) to each COD vial before adding the sample.

Cat. No. Description
Maximum Cl - concentration in sample (mg/L)
Suggested Cl - concentration of diluted samples (mg/L)
Maximum Cl - concentration in sample when 0.5g HgSO4 added (mg/L)
Add to Cart
COD tube test ULR

COD tube test LR

COD tube test HR

COD tube test UHR

TN (Total Nitrogen) tube tests
Nitrogen is found in water as nitrite, nitrate and ammonia. These compounds are important in terms of water economy and waste water technology. Their concentrations fluctuate depending on prevailing conditions (i.e. low or high oxygen). Total nitrogen (TN) also affects the pH and oxygen concentration of the water. This test must be measured using the AQUANALTM-professional SPECTRO 1000 or the AQUANALTM-SPECTRO 3 photometer.

Ammonium tube tests
Ammonia occurs in many forms of surface water and is found in community and industrial waste water as well. The AQUANALTM ammonium tube test determines the ammonia concentration. By using a conversion factor, the concentration of nitrogen from ammonia can be calculated.

Nitrite tube tests
Nitrite is produced by the nitrification of ammonia into nitrate as an intermediate product, principally in low-oxygen water. Nitrite can be toxic for organisms even in low concentrations. The AQUANALTM tube test measures the concentration of nitrite. A conversion factor is then used to calculate the concentration of nitrite nitrogen.

Nitrate tube tests
Due to the high load of nitrates in the environment (NOX from the air, fertilizers, etc.), relatively high nitrate concentrations are also found in drinking water. Nitrate is microbiologically transformed to nitrite, which is an indicator of pollution in the body of water.

TP (Total Phosphorous) and Orthophosphate
Phosphorus compounds are found in various forms in waste water, one being orthophosphate (HPO42-) that can be determined in water without prior decomposition. Organic and inorganic phosphate compounds, which are known collectively as total phosphate, can be determined after decomposition. All of these phosphorous compounds must be included in an accurate study of process water. The AQUANALTM phosphate tests cover the concentrations of phosphate. A factor is used to calculate the concentration of phosphorus.

Ordering Information
Cat. No.
Product Name
Measuring range
Add to Cart
AQUANALTM-COD tube test ULR (150 tests)
2-40 mg/L

AQUANALTM-COD tube test LR (25 or 150 tests)
10-150 mg/L

AQUANALTM-COD tube test HR (25 or 150 tests)
100-1,500 mg/L

AQUANALTM-COD tube test UHR (25 or 150 tests)
1,000-15,000 mg/L

Total Nitrogen tube tests (24 tests, incl. 1 blank)
0.5-140 mg/L

AQUANALTM-Ammonium tube test (24 tests, incl. 1 blank)
0.01-50 mg/L

AQUANALTM-Nitrite tube test (24 tests, incl. 1 blank)
0.1-10 mg/L

AQUANALTM-Nitrate tube test (24 tests, incl. 1 blank)
0.5-60 mg/L

AQUANALTM-Total Phosphorous tube test
0.2-10 mg/L

AQUANALTM-Total Phosphorous tube test
5-60 mg/L

AQUANALTM-Orthophosphate tube test
3-60 mg/L

AQUANALTM-plus THERMOBLOCK® Heating unit for AQUANALTM-professional tube tests

Photometer AQUANALTM-plus SPECTRO COD (CSB)for evaluation of the COD cuvette tests 37735, 37736, 37737, 32031

Photometer AQUANALTM- SPECTRO 3 for AQUANALTM-plus and AQUANALTM-professional reagents

Photometer AQUANALTM-professional SPECTRO 1000

Back to top