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The Analysis of Lead-Based Paint Layers: a Qualitative Comparison of Methods
Published in Joseph J. Breen, Cindy R. Stroup, Lead Poisoning, 2020
R. J. Narconis, V. Divljakovic, S. L. Barnes, A. M. Krebs
Samples were analyzed by inductively coupled argon plasma techniques (ICP). The instrument used was a Thermo-Jarrell Ash Plasma 300. The 1.5-in.2 samples collected from the same location at which XRF data was obtained were weighed and transferred to a disposable culture tube. Three milliliters of redistilled nitric acid and 1 ml of redistilled perchloric acid were then added to the tube, using a graduated pipette. The tubes were then placed in a hot-water bath (190–200°F) and heated until the reaction subsided. The tubes were transferred to a block heater set at 300°F. The samples remained in the heater until complete digestion and white perchloric fumes were evident. After allowing the samples to cool, 0.5 ml of redistilled nitric acid and 2 ml of hydrochloric acid were pipetted into the tubes. The samples were then reheated in a hot water bath, to redissolve salts. After allowing the samples to cool, each sample was transferred quantitatively into 50-ml volumetric flasks. Finally, each sample was mixed and filtered using a 10-cc syringe with a 0.2-μm acrodisc attached. Filtered into clean disposable tubes, the samples were analyzed for lead on ICP at 220.35 nm. Results were originally expressed in micrograms per milliliter and, for comparison to XRF units, were converted to milligrams per square centimeter, using the original sampling area of 1.5 in2 for area in this conversion. Since ICP is the only analytical method of the three performed that is destructive, it was done last.
Laboratory Analysis Procedures
Published in James R. Millette, Steve M. Hays, Settled Asbestos Dust Sampling and Analysis, 2018
James R. Millette, Steve M. Hays
Specifically, the plug from the nozzle of the sampler is removed and the cassette is filled with approximately 10 ml of a mixture of 50/50 alcohol and prefiltered water. The plug is replaced and the cassette is shaken vigorously by hand for 2 or 3 seconds. The entire cap of the cassette is removed and the suspension poured into a precleaned 200 ml glass medical specimen bottle. All visible traces of the sample are rinsed into the specimen bottle with a plastic squirt bottle of 50/50 solution. This procedure is repeated two additional times for a total of three washings. Next, the nozzle is rinsed 2 or 3 times into the specimen bottle. Typically, the total amount of 50/50 solution used in the rinse is approximately 70 to 75 ml. The suspension is then filtered through a 1 mm mesh sieve and collected in a specimen bottle. The liquid level in the specimen bottle is then carefully adjusted to 100 ml with prefiltered water. The pH of the water is adjusted to 3 or 4, using a 1.0% HCl or acetic acid solution. The sample container is capped and placed in a mild ultrasonic bath for 3 minutes to make a uniform suspension. After two minutes of settling, a measured volume of suspension is extracted with a graduated pipette inserted halfway into the sample solution. The aliquot is mixed with particle-free water in the filter funnel and filtered through a 0.22 μm pore size MCE filter backed by a 5.0 μm pore size filter. The 0.22 μm filter is dried and prepared according to the direct filter preparation procedure described in this chapter. A sample blank is prepared in an identical way as the sample.
Phytoremediation of polycyclic aromatic hydrocarbons (PAH) by cv. Crioula: A Brazilian alfalfa cultivar
Published in International Journal of Phytoremediation, 2018
Wilber S. Alves, Evelin A. Manoel, Noemi S. Santos, Rosane O. Nunes, Giselli C. Domiciano, Marcia R. Soares
The column was modified from the “miniaturized chromatographic column” used by Banjoo and Nelson (2005), with the column built in n-hexane using a 5 mL-graduated pipette as column and containing a primary glass wool layer followed by 2 g of 70–230 mesh silica gel, activated for 2 h at 120 °C. A 1-cm anhydrous sodium sulfate layer was added on top, and packing was allowed to occur by gravity. The dried PAH extracts, solubilized in 1 mL of n-hexane, were applied to the top of the column, and the concentrated analytes were eluted with 14 mL of the n-hexane-dichloromethane (8:2) mobile phase into 15-mL penicillin flasks. After solvent evaporation in a hood, samples were stored at −20°C for subsequent analysis and quantification of PAH by reversed phase high performance liquid chromatography (RP-HPLC).
Recycled bio-sourced glycerol and diglycerol for asphalt release agents (ARA)
Published in Road Materials and Pavement Design, 2020
Peter Mikhailenko, Alexandra Bertron, Gildas Nyame Mendendy Boussambe, Romain Valentin, Zéphirin Mouloungui, Erick Ringot
The effects of ARA on the mixture was observed by resistance in ITS as developed previously. The mixture was heated so that it was at 150 ± 10°C before compaction and placed in the mould. The asphalt mix was compacted by a piston pressed (pre-heated to 150 ± 10°C) on the asphalt mix through a compressor and maintained for 3 min at a constant pressure of 2.5 MPa in order to attain a 4–8% voids content in accordance with NF P 98-150-1 for this mixture. The samples produced were Ø100 mm pills, with a height of 62 ± 2 mm and a plain surface on either side. The ARA was applied at 1 mL in the centre of the sample by a graduated pipette just before compaction of the asphalt mix.
Laboratory-scale bioremediation potential of single and consortia fungal isolates from two natural hydrocarbon seepages in Trinidad, West Indies
Published in Bioremediation Journal, 2019
Sheldon Ramoutar, Azad Mohammed, Adesh Ramsubhag
Three 1 cm2 fungal plugs from the leading edge of 5-day old PDA-crude oil cultures of each isolate were inoculated into screw-capped tubes containing 12 mL of BSM broth amended with 16.7% crude oil (167 ml crude oil/L) in duplicate. The tubes were incubated in the shaker for 1 week at 30 °C. The amount of crude oil remaining in tubes after incubation was estimated using a pipette and 1 mL graduated pipette tips. After removal of the crude oil from the surface on the tubes, the mass of fungal hyphae was removed and dry weight determined after drying in an oven at 70 °C until constant weight.