Disposal filters

Water samples were collected in midsummer, precipitation-free periods, following protocols of Ficklin Mosier (1999). On-site measurements include pH, specific conductance, alkalinity, acidity, dissolved oxygen, turbidity, and water temperature. Samples were collected in 1-litre polypropylene bottles and filtered onsite (0.45 pm) with disposable filters. Subsamples for cation analysis were placed in acid-rinsed polypropylene bottles and acidified with ultra-pure HNO3. Filtered, unacidified sub-samples for anion analysis were refrigerated until analyzed. In 2007, samples for Hg analysis were collected no Hg was detected at detection limits of 0.02 pg/L, precluding collection in 2008. 

Ampicillin Dissolve at 50 mg/mL in distilled water, sterilize by filtration through a sterile 0.22-pm disposable filter, and freeze in aliquots at-20°C. 

Common uses for polyester resins are reinforced plastics automotive parts boat hulls foams encapsulation of electrical equipment protective coatings ducts flues and other structural applications low pressure laminates magnetic tapes piping bottles non-woven disposable filters and low-temperature mortars. 

Disposable filters 0.45 pm (e.g. Schleicher Schuell pyrogen free)... 

Reagents. Cyclic nucleotides (3, 5 -cyclic adenosine monophosphate (c-AMP), 3, 5 -cyclic guanosine monophosphate (c-GMP), and 3, 5 -cyclic inosine monophosphate (c-IMP)) sodium tetraborate hydrochloric acid and potassium hydroxide were purchased from Sigma Chemical Company, St. Louis, Missouri). Millex disposable filter units (0.22 pm) were obtained from Millipore Corporation (Bedford, Massachusetts). Triply distilled and deionized water was used for the preparation of buffer solutions. Both buffers and samples were routinely degassed with helium after filtration (using microfilter units). 

Note The purpose of the in line 1-pm filter is to retain any inorganic particles removed from the swab by the organic extraction. The filter and filter holder are an integral part of a subsequent concentration/cleanup procedure for inorganic FDR as outlined in reference 220. The filter unit consists of a 13-mm-diameter Swinnex disposable filter holder containing a 13-mm-diam-eter, 1-pm pore size, fluoropore membrane filter (Millipore FALP 01300). 

Although superficially more expensive, the use of a disposable filter apparatus is far more reliable than the self assembled varieties, which are not recommended for the occasional user. 

Fig. 8.3. Disposable filters. The small Millex filters (a) and the larger Gelman Acrocap (b) can be attached to a syringe or used on line. In both cases positive pressure is used to force the medium through the filter. With the Nalge and Falcon filters (c) negative pressure from a water pump sucks the filtered medium either into the base of the filter or into a receiving vessel. (Courtesy of the manufacturers.)...

For filtration of small volumes (5 -20 ml) disposable filter units are available which can be attached to a disposable syringe (Fig. 8.3). The contents can be expressed directly into a sterile receiving bottle. Such filter units are available from Millipore (Millex Filters), Schleicher and Schuell or Gelman (e.g. Acrodisc 13 Appendix 3) (Fig. 8.3). 

Some of these disposable filter units are shown in Figs. 8.3 and 8.4 and filter units are available for even larger volumes, e.g. MilhPak-100 will cope with up to 75 1 serum-free medium at a flow rate of 35 1 per min. 

It has been reported recently (Knight, 1990) that solutions filtered through disposable filters may be detrimental to the growth of some cells. This is because the filters are treated, during manufacture, with polyglycolethers. These may be removed by washing the filter before use with warm, sterile distilled water followed by a small volume of culture medium. 

The composition of the first treatment can be checked by filtering a sample in the laboratory and then adding a small amount of dilute ferric chloride or aluminum sulfate to the filtrate. Any precipitate indicates that the reaction has not been taken to completion (11-13). The contents of the first treatment tank are then filtered, typically in an open plate and frame filter. The filter cake is discharged periodically for disposal. Filter aid can be added, if required. 

Ceramic membrane systems are achieving widespread appheation in the place of centrifuges. These systems do not require filter aid media or a separate follow-on clarification step. HoUow-fiber crossflow modules are preferred for the separation of mammalian cells, which require particularly gentle handling. They can also be used as disposable filters for perfusion and... 

Headline disposable filter elements are used to collect condensed tar at controlled temperature. These elements are manufactured from precise mixtures of borosilicate glass microfibres. The disposable filter elements offer exceptional filtration efficiency (grade designation, 99,99% removal of 0,1 micron particles) at very low pressure drops. 

Abdel-Hamid et al. [122] used a flow-injection amperometric immunofll-tration assay system for the rapid detection of total E. coli and Salmonella. Disposable porous nylon membranes served as a support for the immobilization of anti- ]. coli or anti-Salmonella antibodies. The assay system consists of a flow-injection system, a disposable filter-membrane, and an amperometric sensor. A sandwich immunoassay specifically and directly detected 50 cells ml total E. coli or 50 cells ml Salmonella. The immunosensor can be used as a highly sensitive and automated bioanalytical device for the rapid quantitative detection of bacteria in food and water. 

Isopropyl P-3-thiogalactopyranoside (IPTG) (Life Technologies) 100 mg/mL in water. Sterilize by filtration through a 0.22-p disposable filter. Store in aliquots at -20°C. 

Liposome running buffer 10 mM HEPES pH 7.2, 0.15 M NaCl, 0.1 mM EDTA. Sterilize running buffer by filtration through 45 pm disposable filter. 

Use Packaging film molded parts for automobiles, appliances, housewares, etc. wire and cable coating food container closures coated and laminated products bottles artificial grass and turfs plastic pipe wearing apparel (acid-dyed) fish nets surgical casts strapping synthetic paper reinforced plastics nonwoven disposable filters. 

When disposable filters are preferred (which may be the case for medical or microbiological analysis), it can be better to elaborate lower cost materials. A new and efficient way to prepare them is by deposition of polymers on patterned substrate structures (such as with phase separation micro-molding). 

The filter is placed on the end of a syringe with a 12 mm diameter membrane. The sample is placed in the barrel of the syringe, and when the plunger is depressed the sample is forced through the membrane. It usually is injected directly into the sample injector. Nylon disposable filters or nylon membranes are available and work well. 

An even jarger cellulose acetate disposable filter of 30 mm diameter was used for the preconcentration of cbppeffiy precipitation of the hydroxide [20]. The large dead volume of the filter seems to have a stronj ihfluence on the perfoimanceTsince CE was estimated to be about 0.7 min" (12-fold enrichment in about 3.5 min), with a consumptive index of about 1 ml. Precision data on the method was not available. 

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