Test Methods & Safety

The following are general descriptions of testing methods utilized in specific LaMotte test kits. Most water analyses are conducted either by titrimetric analyses or colorimetric analyses. Both methods are easy to use and provide accurate results.

Colorimetric

Colorimetric means to measure color. Reagents are added to a sample and a reaction occurs that produces a color, the intensity of which is related to the concentration of the test factor. The concentration is determined by measuring the color, either visually or electronically:

Visual Methods

Octa-Slide and Octet Comparators feature eight color standards with built-in filters that eliminate optical distortion. Some tests include an Axial Reader attachment that uses a mirror to extend the view path and intensify faint colors in low concentrations. Laminated Color Charts offer an inexpensive means of measuring color, and are often used with tablet methods and test strips.

Electronic Methods

Electronic colorimeters or spectrophotometers help eliminate visual inconsistencies and provide a dedicated light source. The light source passes through a sample and is measured by a photodetector. The results are translated to a digital output in ppm, %T, or Absorbance.

Titrimetric:

Titrimetric analyses are conducted by adding a solution of known strength (the titrant) to a specific volume of a sample in the presence of an indicator. The indicator produces a color change, which shows that the reaction is complete. The following methods are most often used in environmental education.

Direct Reading Titrator

The direct reading titrator is a 1.0 mL microburet calibrated to allow direct reading of test results. Each titrator has a specific range, but may be refilled to test higher concentrations.

Dropper Bottle/Pipet

A pipet or special dropper tip fitted onto the reagent bottle is used to deliver a consistent standard drop size. The number of drops used to complete the reaction in the treated sample is multiplied by a given factor to produce the test result.

Electronic:
	Electronic methods generally use a special electrode for measurement of a specific test factor. An electrode is immersed into a sample. A small current or voltage is produced that is amplified electronically and translated into a digital readout.

Safety

Have a question about the use of any LaMotte testing or sampling product? Call LaMotte’s knowledgeable Technical Service Department at 800-344-3100.
Follow all field and laboratory safety guidelines as mandated by your school, center, or education/citizen monitoring program.
Specific instructions are provided with each LaMotte test kit and sampling equipment. Be sure to follow these carefully.
Some reagents (or specific volumes of reagents), as determined by federal and state government safety and regulatory agencies, require an access to a Material Safety Data Sheet. To view or print a MSDS for these reagents see the MSDS CD supplied in the kit or go to www.lamotte.com. To obtain a printed copy contact us by email, phone or fax. Follow all safety precautions and procedures as specified on the MSDS.
Additional information for all LaMotte reagents is available in the United States, Canada, Puerto Rico, and the US Virgin Islands from Chem-Tel by calling 1-800-255-3924. For all other areas, call 813-248-0585 collect to contact Chem-Tel’s International access number. Each reagent can be identified by the 4-digit number listed on the upper left corner of the reagent label, in the contents list, and in the test procedures.

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