Filters for Prefiltration and Contamination Analysis

Millipore fibrous disc filters are available in a wide range of flow rates and throughput capacities. Glass fiber filters are available with or without binder resins and can be sterilized by EO, gamma, or autoclave (121 °C at 1 bar).

Glass Fiber Filters with Binder Resin

Millipore filters with binder resin have superior wet strength and are excellent for qualitative analysis and prefiltration, especially for heavily contaminated liquids. They are also widely used for clarification of aqueous solutions.

Type AP15

Lowest dirt-holding capacity
Recommended prefilter for 0.2 to 0.6 µm filters

Type AP20

Lower retention, higher dirt-holding capacity than AP15 filters
Recommended prefilter for 0.8 to 8.0 µm filters
Use upstream to protect type AP15 filters

Type AP25

Added thickness yields same retention and greater dirt-holding capacity as AP20
Recommended prefilter for 0.9 to 8 µm filters, especially for proteinaceous and heavily contaminated liquids
Use upstream to protect type AP15 filters

Glass Fiber Filters without Binder Resin

The filters without binder resin retain their structural integrity without weight loss when heated up to 500 °C and can therefore be used in gravimetric analysis as well as for the filtration of hot gases.

Type APFA

Retains fine particles with good efficiency, even at high flow rates
Recommended for monitoring wastewater and collecting suspended particles in gases (e.g., fumes from chimneys)
Use in biochemical applications (e.g., collection of cells and filtration of protein or nucleic acid precipitates)

Type APFB

Higher mechanical strength when wet and greater loading capacity than type APFA filters
Use for liquid clarification, quantification of solids in suspensions of fine particles, and scintillation counting

Type APFC

Greater retention, especially for fine particulate and microorganism removal than type APFA filters
Use for determining total suspended solids in drinking water
Use for filtering proteins or nucleic acid TCA precipitates and for collecting cells and microorganisms

Type APFD

Thick filter with high flow and low retention
Use for clarifying suspensions containing particulates > 1.0 µm

Type APFF

Use for filtering extremely fine precipitates such as protein, nucleic acids, or serum precipitates
Recommended for USEPA method 1311 for TCLP analysis

Type AP40

Recommended for Standard Methods Total Suspended Solids 2540D
Recommended for USEPA method 1311 for TCLP analysis
Maintains structural integrity without weight loss when ignited to 550 °C (1022 °F) after sample filtration
Recommended for determining volatile suspended matter in wastewater and industrial effluents

Quartz Fiber Filters (Type AQFA)

Made of very pure quartz fibers with no glass fibers or binders. The pure quartz composition prevents the filters from reacting with acidic gases, unlike glass fiber filters that can react and cause false readings. This makes quartz filters well suited for measuring heavy metal concentrations and small amounts of particles (such as the USEPA PM 10 ambient air monitoring method). The filters also exhibit good weight and form
stability.

Specifications

Filter Code*	Pore Size (µm)	Thickness (µm)	Water Flow Rate (mL/min/cm²)	Air Resistance**	Air Flow***	DOP Penetration****	Protein Binding (µg/cm²)	Weight (g/m²)	Max. Temp. (°C)
Glass Fiber Filters with Binder Resin
AP15	1.0	790	1.6	210	10.6	0.10	100	50	–
AP20	2.0	380	1.3	48	46.4	0.08	60	59	–
AP25	2.0	1200	5.8	35	63.6	0.03	110	140	–
Glass Fiber Filters without Binder Resin
APFA	1.6	230	5	33	67.5	0.002	–	55	500
APFB	1.0	700	2.2	95	23.4	0.002	–	140	500
APFC	1.2	240	1.2	54	41.2	0.002	–	52	500
APFD	2.7	470	2.7	16	139	0.1	–	120	500
APFF	0.7	380	1.4	120	18.6	0.002	–	75	500
AP40	–	475	6	50	44.5	0.002	–	65	550
Quartz Fiber Filters
AQFA	–	430	1.6	50	44.5	0.002	–	85	950
Corresponds to first 4 digits of catalogue number mm of H₂O at 10.5 fpm or 5.3 cm/s Liters/min/cm² at 10 psi **At 10.5 fpm (%)

Compare	Catalogue No.	Filter Code	Filter Diameter (mm)	Qty/Pk
	AP1502500	AP15	25	100
	AP1503700	AP15	37	100
	AP1504200	AP15	42	100
	AP1504700	AP15	47	100
	AP1507500	AP15	75	100
	AP1509000	AP15	90	100
	AP1509050	AP15	90	50
	AP1512450	AP15	124	50
	AP1514250	AP15	142	50
	AP2001000	AP20	10	100
	AP2001300	AP20	13	100
	AP2002500	AP20	25	100
	AP2004200	AP20	42	100
	AP2004700	AP20	47	100
	AP2005500	AP20	55	100
	AP2007500	AP20	75	100
	AP2009000	AP20	90	100
	AP2009050	AP20	90	50
	AP2012450	AP20	124	50
	AP2014250	AP20	142	50
	AP2501000	AP25	10	100
	AP2501300	AP25	13	100
	AP2502200	AP25	22	100
	AP2502500	AP25	25	100
	AP2503500	AP25	35	100
	AP2504200	AP25	42	100
	AP2504700	AP25	47	100
	AP2507500	AP25	75	100
	AP2509000	AP25	90	100
	AP2512450	AP25	124	50
	AP2514250	AP25	142	50
	AP2512750	AP251	127	50

Compare	Catalogue No.	Filter Code	Filter Diameter (mm)	Qty/Pk
	APFA02500	APFA	25	100
	APFA04700	APFA	47	100
	APFA09050	APFA	90	50
	APFA15050	APFA	150	50
	APFB02500	APFB	25	100
	APFB03700	APFB	37	100
	APFB04700	APFB	47	100
	APFB09050	APFB	90	50
	APFB11050	APFB	110	50
	APFB15050	APFB	150	50
	APFC02500	APFC	25	100
	APFC03700	APFC	37	100
	APFC04200	APFC	42.5	100
	APFC04700	APFC	47	100
	APFC09050	APFC	90	50
	APFD02500	APFD	25	100
	APFD03700	APFD	37	50
	APFD04700	APFD	47	100
	APFD09050	APFD	90	50
	APFD14250	APFD	142	50
	APFF02500	APFF	25	100
	APFF04700	APFF	47	100
	APFF09050	APFF	90	50
	APFF12450	APFF	142	100
	APFF14250	APFF	142	50
	AP4001000	AP40	10	100
	AP4002405	AP40	24	500
	AP4002500	AP40	25	100
	AP4003705	AP40	37	500
	AP4004700	AP40	47	100
	AP4004705	AP40	47	500
	AP4007000	AP40	70	100
	AP4009000	AP40	90	100
	AP4014250	AP40	142	50
	AP4011050	AP40	110	50
	AP408X105	AP40		50