A.R. ALATAN SAINS (K) SDN. BHD.

These filters are used in qualitative analytical techniques to determine and identify materials

Grade 1 : A medium retention and flow rate filter for routine applications, including soil analysis and seed testing procedures, food industry testing, air pollution monitoring and gas detection.

Grade 2 : More absorbent and slightly more retentive with a slower filtration speed than Grade 1. Use for monitoring specific contaminants in the atmosphere and in soil testing.

Grade 3 : A thick filter with good loading capacity, fine particle increased strength. The extra thickness give increased wet strength and make the filter suitable for use in buchner funnels. The high absorbency is particularly valuable when the filter is used as a sample carrier.

Grade 4 : Offers high flow rate with good retention of larger particles and gelatinous precipitates such as ferric hydroxide and aluminum hydroxide. Also used as a rapid filter for routine cleanup of biological fluids or organic extracts and for rapid air pollution monitoring where collection of fine particles is not critical.

Grade 5 : The most efficient qualitative filter. Used for collecting small particles and has a slow flow rate. Suitable for chemical analysis clarifying clodly suspensions, and for water and soil analysis.

Grade 6 : Twice as fast as Grade 5 with similar particle retention. Often specified for boiler water analysis.

Wet strengthened qualitatve filters contain a small quantity of a chemically stable resin to give improved wet strength. This does not intoduce any significant impurities into the filtrate but but because the resins contain nitrogen, these grades should not be used in Kjeldahl estimations.

Grade 91 : A general purpose creped filter for less critical routine analysis. Widely use to assay sucrose in cane sugar and within pharmaceutical laboratories for routine filtration.

Grade 93 : Widely use in universities, colleges and schools for general laboratory filtration and coarse sample preparation.

Grade 113 : A creped filter with high loading capacity and the fastest flow rate of any qualitative grade. This is the thickest flter in the range and is extremely strong. Grade 113 is ideal for use with coarse or gelatinous precipitates.

Grade 114 : Half of the thickness of Grade 113, this is very strong filter with a smooth surface for easy recovery of precipitates. It is suitable for coarse or gelatinous precipitates.

Whatman Quantitative filters are designed for gravimetric analysis and the preparation of samples for instrumental analysis. Whatman ashless filters are produced from high quality cotton linters under carefully controlled conditions. These very pure filters are ideal for a wide range of critical analytical filtration procedures.

Grade 40 : General purpose ashless filter. Applications include gravimetric analysis, the filtration of solutions prior to atomic absorption spectrophotometry and in air pollution monitoring.

Grade 41 : The fastest ashless filter is recommended for analytical procedures involving large particles or gelatinous precipitates such as iron or aluminium hydroxides. Also used in quantitave air pollution analysis for determining gaseous compounds at high flow rates.

Grade 42 : Filter wth the finest particle retention. Typical analytical precipitates include barium sulfate, metastannic acid and finely precipitated calcium carbonate.

Grade 43 : A moderately fast filter used for foodstuff analysisi, soil analysis, particle collection in air pollution monitoring and inorganic analysis in the construction, mining and steel industries.

Grade 44 : Gives the lowest ash weight for any given disc size. Slightly less efficient for collecting small particles than grade 42 but has a higher flow rate.

Whatman Quantitative filters are designed for gravimetric analysis and the preparation of samples for instrumental analysis. Hardened low ash filtersa treated with a strong acid to produce high wet strength and chemical resistance. These filters are particularly suitable for Buchner filtration where the tough smooth surface of the filter makes it easy to recover precipitates.

Grade 50 : The hardened surface is virtually free from loose fibers. In the electronic industry, the virtual absense of fiber shedding is utilized in carriers for integrated circuits.

Grade 52 : Ideal for use with Buchner funnels or Whatman 3-piece filter funnels.

Grade 54 : High wet strength is suitable for vacuum-assisted fast filtration of difficult materials.

Whatman Quantitative filters are designed for gravimetric analysis and the preparation of samples for instrumental analysis. Hardened ashless filters are acid hardened to give high wet strength and chemical resistance with extremely low ash content. The tough surface makes these filters suitable for a wide range of critical filtration procedures.

Grade 540 : Frequently used in gravimetric analysis of metals in acid/alkali solutions..

Grade 541 : Typical applications include protein determination, cement analysis and the determination of fiber in animal food.

Grade 542 : Slow flow rate. Very hard and strong with excellent chemical resistance. Often used in gravimetric metal determinations.

Whatman glass microfiber filters are manufactured from 100% borosilicate glass and are chemically inert and completely binder free. These depth filters combine fast flow rates with high loading capacity and the retention of very fine particles, extending into the sub-micron range. Glass microfiber filters can be used at temperature up to 500°C and are ideal for use in applications involving air filtration and for gravimetric analysis of volatile materials where ignition is involved.

Whatman glass microfiber filters have a fine capillary structure and can absorb significantly larger quantities of water than an equivalent cellulose filter, making them suitable for spot tests and liquid scintillation counting methods. The filters can also be made completely transparent for subsequent microscopic examination.

Grade GF/A : Suitable for suspended solids in all types of water and effluent and filtration of particulates in water, algae and bacterial cultures. Also widely used for air pollution monitoring.

Grade GF/B : Recommended for concentrated suspensions and retention of small particles. Suitable for suspended solids in industrial effluents, especially at high loading.

Grade GF/C : Used in many parts of the world for collection of suspended solids in potable water and natural and industrial waste. Widely used in biochemistry for cell harvesting, liquid scintillation counting and binding assays.

Grade GF/D : General purpose membrane prefilter with high loading capacity.

Grade GF/F : Suitable for critical applications including enumeration of Salmonella and Pseudomonas Aeroginosa, clarification of protein solution and filtering samples and solvents prior to HPLC. EPA Standard for Toxicity Characteristic Leaching Procedure, Method 1311. Recommended for DNA binding and purification.

Grade 934-AH : Specified in standard methods for determining total suspended solids in water, removal of turbidity and filtration of bacterial cultures. Particularly recomended for water pollution monitoring, cell harvesting, liquid scintillation counting and air pollution monitoring.

Grade EPM 2000 : Has been developed and produces especially for use in high volume PM-10 air sampling equipment that collect atmospheric particulates and aerosols.It is manufactured from 100% pure borosilicate glass of special purity enabling details chemical analysis of trace pollutants with the minimum of interference or background. Whatman EPM 2000 was selected by the EPA to be the standard filter for use in nationwide network of air samplers. Sheets are individually numbered to faclitate identification.

Grade QM-A : High-purity quartz (SiO2) microfiber filters are used for air sampling in acidic gases, stacks, flues and aerosols, particularly at high temperatures up to 500° C and in PM-10 testing. Because of the low level of alkaline earth metals, "artifact" products of sulfates and nitrates (from SO2 and NO2) are virtually eliminated. QM-A, sequentially numbered according to EPA standards, is suitable for most applications.