Quantitative Ashless Filter Paper, 351 Grade, 55mm - 320mm

£10.48 to £100.79

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Variation ID		Product Code	Pack Size	List Price
23885	photo_camera	351055	55mm x 100 Pack 351055	£10.48
23886	photo_camera	351070	70mm x 100 Pack 351070	£12.12
23887	photo_camera	351090	90mm x 100 Pack 351090	£14.91
23888	photo_camera	351110	110mm x 100 Pack 351110	£18.60
23889	photo_camera	351125	125mm x 100 Pack 351125	£21.69
23890	photo_camera	351150	150mm x 100 Pack 351150	£27.74
23891	photo_camera	351185	185mm x 100 Pack 351185	£38.32
23892	photo_camera	351240	240mm x 100 Pack 351240	£59.12
23893	photo_camera	351300	300mm x 100 Pack 351300	£87.68
23894	photo_camera	351320	320mm x 100 Pack 351320	£100.79

Ashless Quantitative Filter Papers are high-purity filters made from 100% cotton linters and acid-washed to remove impurities. With an ash content of just 0.007%, they are ideal for gravimetric analysis and sample preparation where minimal residue is critical. These papers offer excellent wet strength, making them suitable for use with Buchner funnels in quantitative applications. Available in a wide range of pore sizes and formats, they meet international standards for analytical filtration.

Grade 351: is the finest retention grade in the Johnson Test Papers quantitative range. It is specifically suited for filtering very fine precipitates such as barium and lead sulphates, stannic and nickel sulfides, calcium oxalate, calcium fluoride, and cuprous oxide. Its precision makes it ideal for applications in industries like cement testing, where it is commonly used for calcium carbonate separation. Grade 351 is also recommended for analysing insoluble particles in oils and fats, and for preparing samples for sensitive instrumental analysis where even trace particulate matter must be removed.

Application: Fine pores used for extremely difficult filtration conditions such as cold barium sulphate, metastannic acid, cuprous oxide.

Key Features

Extremely Fine Retention: Designed to capture the smallest precipitates with high accuracy.

Low Ash Content: Just 0.007%, supporting reliable gravimetric and instrumental results.

High Particle Purity: Ensures clean separation without introducing analytical interference.

Specialised Use: Suitable for sample preparation in industries involving coatings, glazes, pigments, and lubricants.

Precision Filtration: Helps prevent contamination in highly sensitive testing workflows.

Cement analysis (e.g. calcium carbonate separation)
Gravimetric analysis of metal sulfides and oxalates
Clarification of oils, animal and vegetable fats
Pigment, glaze, and coating filtration in material science
Sample cleanup prior to instrumental analysis (e.g. ICP, AAS)

Available Grades

Grade	Whatman Equivalent	Speed	Thickness (mm)	Pore Size (μM)	Weight (g/m²)	Filtration Speed (sec*)	Burst Strength (kg/cm²)
351	= No.42	Very Slow Filtering	0.14	2-3	84	180	> 0.20
352	= No.40	Medium Filtering	0.15	3-5	84	100	> 0.20
353	= No.43	Medium fast filtering	0.16	5-8	84	50	< 0.20
354	= No.41	Fast Filtering	0.17	8-12	84	20	> 0.20a