Methods Of Determination

TDS: Conductivity Meter

TSS: Filtration, Turbidity meter or Nephelometer (lower values)

Precautions during filtration: - "wash" the filter and sample with deionized water after filtering the sample and before drying the filter.

BOD and DO: Dilution Method

Colour: Spectrophotometry

Spectrophotometry involves the use of a spectrophotometer. A spectrophotometer is a photometer (a device for measuring light intensity) that can measure intensity as a function of the color (or more specifically the wavelength) of light. Important features of spectrophotometers are spectral bandwidth and linear range of absorption measurement.

Nitrate, Chloride and Phosphate: Determination of Nitrate ( Titrimetric Method )

A titrimetric method is devised to determine the presence of nitrate in water. This method involves the use of a dye known as the azo dye. This dye is the combination of sulfanilamide and N-1 naphthylethylenediamine. The dye is pinkish-red in colour. The end point is reached when the pinkish-red colour turns into yellow. This utilizes the use of hypochlorite. Before the titration begins, nitrate is reduced to nitrite at ph8-9 using cadmium amalgam.

The advantages of this new titrimetric method are that it only takes about two minutes and it offers an alternative analytical procedure in situations when spectrophotometry is impractical.

Ultraviolet Determination of Chloride in Water by Flow Injection Analysis

This method uses the hg-EDTA complex as a reagent. This method has a detection limit of 0.2ppm chloride.

The method was used for the determination of chloride in natural waters and potable water supplies. The effects of sample volume, flow rate, coil length, and possible interferences on the FIA spectrophotometric signals were reported.

Flow Injection Analyzer

Determination of phosphate

A simple spectrophotometry is developed for the determination of phosphate in water sample. This method is based on the formation of phoshomolybdate with added molybdate followed by its reduction with sodium sulphide in aqueous sulphuric acid medium.

Hardness: EDTA titrimetric method

Rapid determination of total hardness in water using fluorescent molecular aptamer beacon

COD:Colorimetry or Spectrophotometry

Precautions:

In carrying out the following procedures, use proper safety measures, including protective clothing, eye protection, and a fume hood. Reagents containing heavy metals (HgSO₄ and Ag₂SO₄) should be disposed of as toxic wastes.

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pH: pH Meter, Litmus Paper

Precaution: needs to be calibrated to read the pH correctly, within the expected pH range of your sample