Glassware disposal

In addition to laboratoiy glassware and equipment necessary fOT cleanup of the extract, traditional pesticide residue methods require expensive chromatogrsqihic instrumentation for identification and quantitation of residues. EIA methods require minimal amounts of glassware, disposable plasticware, or other supplies. Quantitative EIAs often make use of 96-well microtiter plates fOT multiple simultaneous assays of about a dozen extracts and associated reference standard. Major equipment consists of a plate reader, which automatically measures the absorbance of each well. Plate readers can be used alone or in conjunction with a personal computer, which can correlate replicate measurements, construct the calibration curve, calculate results, and provide a complete statistical analysis. Such an EIA workstation can be obtained for roughly half the cost of the GC or HPLC system typically used for pesticide residue analysis. 

This short section is presented for state regulators, residents, and stakeholders to illustrate that the EPA is not beyond the reach of such requests. Very early in the partnering, the District of Columbia asked the EPA to perform some arsenic sampling on the American University campus and several other properties. They complied and found several elevated readings. It was during this sampling event that the District found the glassware disposal site on the campus. They asked Ken Shuster of the EPA to compile a list of the best metal detection equipment. He recommended several firms to the Corps. 

Dry heat sterilisation is used for equipment that can withstand high temperature and dry heat but cannot withstand wet or steam autoclave. This method is often used for glassware as it dries and sterilises in one operation. The pipets must be wrapped in dustproof aluminum foil or placed in metal pipette cans. The can lids are removed during heating and replaced after sterilisation, that is before any dust can get in the can. Disposable items are not recommended for dry heat sterilisation. This method may only be good for permanent reusable glass pipettes. 

The other option is weighing. Since low-tech glassware or disposable pipettes could continue to be used, obtaining a tare and a total weight on a top-loading balance would add only a few seconds for each sample, but inherently be much more accurate and precise than any operation involving just pipettes and graduated flasks. s... 

Initially, this method utilized 5-mL conical centrifuge tubes as the collection device for final elution of the extract from the Cig tubes. In practice, these tubes were found to be very difficult to clean and in few instances were the cause of cross-contamination when low-concentration samples were extracted following samples with very high concentrations. Since no commercial graduated tubes were available, disposable culture tubes are used as the receiver. These tubes are individually calibrated before use. A solvent blank sample may be processed through the method from extraction to quantification to determine if contamination from glassware occurs. 

Dispose of all materials as your teacher directs. Clean all glassware thoroughly with soap and water. 

References to sample contaimination in the literature are numerous. Abercrombie, ef. oJ.(54) have noted that the information obtainable from ICP emission analysis warrants additional care because of the increased number of elements monitored. For example, if one were looking for boron and sodium, the use of glassware should be avoided. Certain digestion vessels that are presumed to be cleaned may not be acceptable. Polyethylene bottles (acid-soaked), for example, have been shown to continue releasing zinc from the matrix for as long as seven days(92). A number of trace elements may be leached from commercial disposable test tubes. Some of the more important contaminants include Ba, Sr, Zr, Na, K, Al, Ca and Mg. 

All broken glassware and dirty paper towels must also be segregated for separate disposal. See the instructor or supervisor for the procedure to follow. 

Samples should be collected aseptically in nonpyrogenic containers. Reused depyrogenate glassware or sterile, disposable polystyrene plastics are recommended to minimize adsorption of endotoxin. 

Willett LB, Brumm CJ, Williams CL. 1978. Method for extraction, isolation, and detection of free polybrominated biphenyls (PBBs) from plasma, feces, milk, and bile using disposable glassware. J Agric Food Chem 26(1) 122-126. 

Cautiont Hexamethylphosphoric triamide and trichloroethylene are oancer-suepect agents. All operations with either one should be performed in an efficient hood. The use of disposable gloves is highly recommended. Glassware should be rinsed with copious amounts of water into separate waste containers before removal from the hood. 

All toxic materials were disposed of in accordance with "Prudent Practices in the Laboratory" National Academy Press Washington, DC, 1995. Wastes containing chromium, aqueous solutions as well as solids, were collected and disposed of separately. Prior to washing, all glassware laden with chromium by-products, were soaked overnight in a solution composed of 15-20 g of copper beads dissolved in -2 L of 50% aqueous nitric acid. This solution may be kept loosely capped in a fume hood and reused several times prior to disposal. 

All toxic materials were disposed of in accordance with Prudent Practices in the Laboratory" National Academy Press Washington, DC, 1995. Clorox solutions were used for cleaning reaction glassware. 

Caution. Chlorotributylstannane and l-(tributylstannyl)indene should be considered toxic and thus should be handled with gloves in an adequate fume hood. All glassware and equipment should be treated with a saturated KOH/isopropanol base bath before being taken out of the fume hood. The base bath can later be disposed with the waste tin compounds. 

Two types of containers should be available for disposal purposes. One should be labeled Liquid Radioactive Waste and used for all waste solutions the other, Solid Radioactive Waste, for blotter paper, broken glassware, etc. Liquid wastes must not be poured down any drain, nor solid wastes deposited in normal trash cans. 

Contaminated glassware should be kept separated from uncontaminated. Contaminated beakers and flasks are placed in the special sink or other container for washing. Clean and wash all equipment with soap and water immediately after the experiment has been completed. If water-insoluble materials are being used, the first washing should be done with an organic solvent such as acetone. Soak contaminated pipets in a container filled with water. All broken glassware is disposed of in the Solid Radioactive Waste container. 

Caution. Chalcogenophenols have an unpleasant odor and are toxic. H2S, H2Se, or H2Te may be liberated on treatment with acid or exposure to the open air. These compounds should therefore be handled under inert gas in a well-ventilated hood. Contaminated glassware should be treated with sodium hypochlorite (bleach) solution for several hours and rinsed thoroughly with water and acetone before removal from the fume hood. Mercury and mercury salts are highly toxic, and skin and eye contact must be avoided. Mercury residues should be disposed of as toxic heavy metal waste. 

Caution. The residues on the glassware and the frit may contain sodium-potassium alloy and/or tris(trimethylsilyl)arsine and should not be exposed to air until disposal. tert-Butyl alcohol and isopropyl alcohol can be used to destroy these pyrophoric compounds however, this should be performed in a fume hood, as arsine gas may be generated. The solid on the frit can be mixed with class D metal fire extinguisher and subsequently treated with either of the aforementioned alcohols. 

Disposable glassware may also be cleaned as a precaution against contamination. An alternate cleaning procedure based on saponification of fat adhering to the glassware is described in AOCS Method Cd I2b 92. 

It is essential that glassware not be contaminated with trace metals or other pro-oxidants. If this is a problem, consider disposing of the glass sample tubes after a single use. 

Contamination of glassware by soap residue, resulting in turbid test solutions, can interfere with the assay during the color development step. For this reason, the use of disposable polypropylene centrifuge tubes has been recommended. Any variation in the procedure outlined may affect the results. By observing the protocol carefully and analyzing at appropri-... 

Caution The nitrosamine (S)-5 may be carcinogenic. All operations with fs)-5 should be performed in a well-ventilated hood, and the operator should wear disposable gloves. In order to destroy any nitrosamine traces, the glassware contaminated with (S)-5 should be immersed in a bath of HBr/aeetic acid. 

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