Whatman / Schleicher & Schuell (GE Healthcare)

Photo of Whatman Grade 114V Fluted Qualitative Filter Papers Wet-Strengthened

Whatman Grade 114V is the same paper as Grade 114, except fluted/prepleated. Strong, wet-strengthened filter with very fast flow rate (25 µm retention). Ideal for coarse particles and gelatinous precipitates. Smooth surface. 100/box.

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Photo of Whatman Grade 541 Quantitative Filter Papers, Hardened Ashless

Whatman Grade 541 acid hardened cellulose filter paper features high wet-strength, high chemical resistance and a large 22 µm nominal particle retention for fast analytical filtration. Maximum of 0.006% ash concentration. 100 circles/box.

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Photo of Whatman Grade 540 Quantitative Filter Paper, Hardened Ashless

Whatman Grade 540 filter paper is frequently used as a gravimetric filter during analysis of metals in acidic or alkaline solutions and in the collection of hydroxides. The acid-treated surface prevents tearing during filtration and allows the user to scrape precipitates from the paper. Nominal particle retention of 8 µm. 100/box.

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Photo of Whatman Grade 54 Quantitative Filter Paper

Whatman No. 54. Quantitative, hardened, low ash. Very fast filtration and 20-25 µm. retention. For use with coarse and gelatinous precipitates. High wet-strength. 100 circles/box.

Photo of Whatman Grade 50 Quantitive Filter Paper

Whatman No. 50. Quantitative, hardened, low ash. Retention of finest crystalline precipitates (2.7 µm). The thinnest of all Whatman filter papers. Slow flow rate. Hardened and highly glazed surface. This finish also keeps the paper free from loose surface fibers. Highly suitable for qualitative or quantitative filtrations requiring vacuum assistance on Büchner or 3-piece filter funnels. Very strong when wet. Will withstand wet handling and precipitate removal by scraping. In the electronics industry, the virtual absence of fiber shedding is utilized in carriers for integrated circuits.

Photo of Whatman Grade 44 Quantitative Filter Paper

Whatman No. 44, quantitative ashless. Thin version of Grade 42 retaining very fine particles (3 µm) but with lower ash weight per sample and almost twice the flow rate as Grade 42. 100 circles/box.

Photo of Whatman Grade 43 Quantitative Filter Paper

Whatman No. 43. Intermediate in retention (16 µm) between Grade 40 and 41, and twice as fast as Grade 40. Typical applications include foodstuffs analysis; soil analysis; particle collection in air pollution monitoring for subsequent analysis by XRF techniques; and inorganic analysis in the construction, mining and steel industries. 100 circles/box.

Photo of Whatman Grade 42 Quantitative Filter Paper

Whatman No. 42 is a world standard for critical gravimetric analysis with the finest particle retention (2.5 µm) of all Whatman cellulose filter papers. Typical analytical precipitates include barium sulfate, metastannic acid and finely precipitated calcium carbonate. 100 per box.

Photo of Whatman Grade 41 Quantitative Filter Paper

Whatman No. 41 is the fastest ashless filter paper, recommended for analytical procedures involving coarse particles or gelatinous precipitates (e.g., iron or aluminum hydroxides). Retention is 20 to 25 µm. Also used in quantitative air pollution analysis as a paper tape for impregnation when determining gaseous compounds at high flow rates. This filter is also available in the Whatman Disposable Filter Funnel. This is a convenient, disposable 47mm filter funnel with a 250mL capacity. The 47mm Grade 41 filter can be easily removed for further analysis or culturing. 100 circles/box.

Photo of Whatman Grade 40 Quantitative Filter Paper

Whatman No. 40 is the classic general purpose quantitative ashless filter paper with medium speed and retention (8 µm). Typical applications include gravimetric analysis for numerous components in cements, clays, iron and steel products; as a primary filter for separating solid matter from aqueous extracts in general soil analysis, quantitative determination of sediments in milk and as a pure analytical grade clean-up filter for solutions prior to AA spectrophotometry. Used also as a high purity filter in the collection of trace elements and radionuclides from the atmosphere.

Photo of Membrane Filters, Whatman WTP (PTFE)
One of the major applications for the PTFE (Type WTP) filter is the clarification of corrosives, solvents and aggressive fluids. This includes the important requirement in HPLC analysis for sample filtration where any solid particles can cause permanent damage to the column. The 0.5µm pore size is normally used. Air and gas sterilization make use of the hydrophobic characteristics of PTFE membranes and their ability to stop aqueous aerosols. Usual pore sizes are 0.2µm and 0.5µm.
OE67 0.45µm cellulose acetate membrane filters exhibit very low protein binding capacity. They are hydrophilic making them suitable for aqueous and alcoholic media. The cellulose acetate membranes have improved solvent resistance, particularly to low molecular weight alcohols and increased heat resistance. With high physical strength, the membrane filters can be used up to 180°C; suitable for hot gases and can be sterilized by all methods without sacrificing the integrity of the membrane.
Photo of Nylon Membranes. Whatman WNYL
Whatman nylon membranes are available in pore sizes ranging from 0.1µm to 0.45µm and in diameters from 13mm to 142mm. These membranes are ideally suited to many applications. In the biotech area, they are used to filter tissue culture media, microbiological media, buffers and solutions. For chromatography applications, they are used to filter samples, aqueous and organic mobile phases and can also be used for vacuum degassing. Nylon membranes are intrinsically hydrophilic, eliminating the need for wetting agents that could possibly be extracted when filtering aqueous solutions.
Photo of Anopore® Inorganic Membranes. Whatman
The Anopore® Anodisc inorganic membrane is ideal for a wide range of laboratory filtration applications. This unique material has a precise, non-deformable honeycomb pore structure with no lateral crossovers between individual pores. Filters at precisely the stated cutoff, allowing no larger sized particles to pass through the membrane. The Anopore® inorganic membrane is composed of a high purity alumina matrix that is manufactured electrochemically. The membrane also exhibits low protein binding, has minimal autofluorescence, is non-toxic and supports cellular growth.
Photo of Cyclopore Polycarbonate Membrane Filters. Whatman
These membranes are available in pore sizes ranging from 0.1µm to 12 µm. Hydrophilic as standard, Cyclopore polycarbonate membranes can also be made hydrophobic upon request. They feature a zero level of non-specific protein binding. The high selectivity of Cyclopore polycarbonate membranes allows precise particle separation and fractionation. Additionally, the smooth and flat surface provides an excellent support for all applications requiring detailed observation of collected samples. Cyclopore's patented membrane technology leaves surfaces perfectly flat and smooth.
Photo of Mixed Ester Membrane Filters. Whatman
Whatman black and green mixed ester membranes are composed of cellulose acetate (20%) and cellulose nitrate (80%). These membranes are characterized by a smoother and more uniform surface than pure nitrocellulose filters. Also, the color contrast provided by the filter surface facilitates particle detection and minimizes eye fatigue. Compared to pure nitrocellulose filters, mixed ester membranes have a smoother and more uniform surface as well as offer color contrasting, making it easier to detect particles.
Photo of Sterile Cellulose Nitrate Membrane Filters, Gridded. Whatman
Whatman WCN cellulose nitrate membrane filters pre-sterilized in gridded style. This grade is manufactured under strictly controlled cleanroom conditions. These sterile filter papers are primarily used in microbiological laboratory applications. Cellulose nitrate membrane filters are the standard filter for the majority of laboratory applications involving particles and cells in the range of 0.11µm to 5.0µm. These sterile filters are supplied individually packed, with or without an absorbent pad included, in sealed polyester envelopes.
Photo of Membrane Filters, Cellulose Nitrate. Whatman
Whatman Type WCN (cellulose nitrate), white, plain. The standard membrane filter for the majority of laboratory applications involving particles in the 0.1-5.0 µm. size range. Suitable for all aqueous based gravimetric and clarification techniques.
Photo of Whatman S&S Grade 589/3 Blue Ribbon Ashless Quantitative Filter Paper

Blue Ribbon Filter 589/3 ashless standard filter paper for very fine precipitates (class 2d acc. to DIN 53 135). 2 µm retention. Slow filter paper with highest efficiency for collecting very small particles. Also used for many analytical routine methods in different industries, e.g. determination of the amount of insoluble contaminants in animal and vegetable fats and oils.

Photo of Whatman 934-AH Glass Microfibre Filters

Whatman 934-AH. The fine particle retention (1.5 µm) and flow rate (13.0 mL/sec) of this popular grade is superior for its high retention efficiency at high flow rates and its high loading capacity. This filter is a smooth surface, high retention borosilicate glass microfiber which withstands temperatures over 500°C. Specified in Standard Methods 2540D for determining total suspended solids in water, removal of turbidity and filtration of bacterial cultures. Grade 934-AH is used for a wide range of laboratory applications.