Johnson Analytica (Johnsons Test Papers) has been manufacturing easy to use rapid tests since 1938 providing fast and accurate results you can trust. Their products cover everything from simple pH testing, water analysis, production processes and measurements of special food parameters.
Wet-strengthened filter papers are manufactured from a majority of alpha-cellulose. The smooth surface allows for fibre free filtration. They feature a high wet strength and can also be used in the filtration of strong alkaline or acid solutions. Due to their high mechanical strength, they are suited to applications where the residue is removed from the filter, for example with a spatula or a jet of water.
What is Grade 304? This grade covers a wide range of laboratory applications and is used for clarifying liquids and for the rapid filtration of coarser precipitates such as lead sulfate, lead chromate, calcium oxalate, calcium carbonate, aluminum phosphate, barium carbonate and beryllium hydroxide.
Grade 304 can be found in soil analysis, seed testing and in air pollution to collect dust-laden air and is also commonly used in the food industry to separate foodstuffs from associated extracting liquid.
Strips can be held in the specimen until the final colour change is observed, they can be used consistently with minimal risk in weakly buffered solutions
Colours can be matched accurately with the colour chart as there is no cross-contamination between the pads on the strip.
No specimen contamination
Slim packaging provides portability and safety
Nothing to prepare before use
Consistent batch to batch measurements against accurately printed colour charts
This fast filtering grade, with extremely high loading capacity is recommended for the filtration of coarse and gelatinous precipitates. The creped surface of Grade 325 also offers higher surface area to increase filtration speed.
Grade 352 high purity filters from Johnson Test Papers are general-purpose papers for quantitative analysis. This grade has medium flow rate and good particle retention and is the most commonly used acid-washed filter. High-purity filters support accurate analysis in applications sensitive to very low levels of background contamination and in gravimetric analysis where ash content might affect weight measurements of combusted samples.
Specifications:
Sizes: 55 to 320 mm
Whatman Cross Reference = No.40
Speed class: Medium
Filtering Thickness (mm) 0.15
Pore size (μM) 3-5
Weight (g/m²) 84
Filtration Speed (sec*) 100
Burst Strength (Kg/cm²) > 0.20
Qualitative analysis
Low ash content 0.07% (Acid wash treated)
High wet strength
Consistent performance Hardened grades available
Custom cut
Bulk packaging
Made of 100% cotton linters
Supplied in rolls, sheers, discs and folded filters
J-QUANT® Fluoride J-QUANT® Fluoride 100 Test Strips are used for determining the amount of fluoride in tap water supplied by local water supply companies. They assist by providing a semi-quantitative value either below or above predetermined guidelines and allow for quick assessment of the amount of fluoride. Carrying out the test by including sodium dithionite in the sample will prevent the white discolouration generated by chlorates and bromates without influencing the result.
Measurement of total sulphite requires further sample preparation
Sulphite is utilised as an oxygen scavenger in process and boiler water, sulphite levels therefore need to be frequently monitored to prevent over treatment
Also used for food analysis e.g. fruit juice testing, sulphurated foods (e.g. fresh and dried fruits), shellfish, crustaceans and minced meat products which use sulphur based products to prolong shelf-life
Used to monitor production and quality of wine
Compatible with sulphite, bisulphite and metabisulphite ions
Useful for many applications, e.g. In chemical laboratories, organic solvents containing peroxide can be checked as they could explode upon heating.
Soak the test pad in the solvent sample then allow to dry
Add a drop of distilled/demineralised water and if the pad remains white then there is no peroxide present.
Testing for residual peroxide where high strength disinfectants are utilised for cleaning such as the dairy industry, drinking water, pools and hot tubs
Nitrite can provide an indication of contamination in the environment.
Aquarium, industry, wastewater and drinking water analysis is, therefore, an appropriate list of examples where nitrite measurement is possible.
Nitrite build up in aquacultures and fish farming through the breakdown of organic matter can impair the filtration units ultimately causing harm to the fish.
It is very important therefore to test for nitrites in this environment.
Peroxide based disinfectants usually come in concentrate form to save on shipping charges and require diluting before use.
Depending on the industry and the disinfecting purpose different concentration levels are required
Therefore these strips provide assurance that disinfection has taken place correctly by providing a semi-quantitative result
Appropriate for measuring inorganic peroxides in aqueous liquids Also suitable for disinfecting and rinsing solutions e.g. food technology, laundries and in swimming pool water
Peracetic acid based disinfectants usually come in concentrate form to save on shipping charges and require diluting before use.
Depending on the industry and the disinfecting purpose different concentration levels are required. Due to its measuring range this test is suited to testing for the effective levels of peracetic acid in such disinfectants.
Therefore these strips provide assurance that disinfection has taken place correctly by providing a semi-quantitative result Peracetic acid is unstable therefore frequent testing is required.
