PESTLE analysis

In this experiment students measure the length of a pestle using a wooden meter stick, a stainless-steel ruler, and a vernier caliper. The data collected in this experiment provide an opportunity to discuss significant figures and sources of error. Statistical analysis includes the Q-test, f-test, and F-test. 

Because of the risk of lead poisoning, the exposure of children to lead-based paint is a significant public health concern. The first step in the quantitative analysis of lead in dried paint chips is to dissolve the sample. Corl evaluated several dissolution techniques. " In this study, samples of paint were collected and pulverized with a Pyrex mortar and pestle. Replicate portions of the powdered paint were then taken for analysis. Results for an unknown paint sample and for a standard reference material, in which dissolution was accomplished by a 4-6-h digestion with HNO3 on a hot plate, are shown in the following table. 

Samples of animal bones weighing approximately 3 g are ashed at 600 °C until the entire bone is ash-white. Samples are then crushed in a mortar and pestle. A portion of the sample is digested in HCl and diluted to a known volume. The concentrations of zinc and strontium are determined by atomic absorption. The analysis for strontium illustrates the use of a protecting agent as La(N03)3 is added to prevent an interference due to the formation of refractory strontium phosphate. 

On the other hand, quantitative extraction requires complete and exhaustive extraction and no material can be lost. To assure complete extraction when a food is analyzed for the first time in a laboratory, it is useful to carry out two or three extractions, pool the solvents, and keep separate the next extracts to verify the presence of carotenoids. Usually four to six extractions are enough to remove the carotenoids completely from a sample. The extraction can be carried out in a blender, vortex, or with a mortar and pestle. Accelerated solvent extraction (ASE), an important extraction technique in residue analysis, currently attracts interest due to its short duration, low level of solvent use, and high extraction yield. The average recoveries for all carotenoids with the exception of norbixin ranged from 88.7 to 103.3% using manual extraction and from 91.0 to 99.6% by ASE (70 bar and temperature of 40°C) both extractions were carried out with a mixture of MeOH, EtOAc, and petroleum ether (1 1 1). ... 

The primary consideration for all AEM analysis is that the specimen be thin (generally carbon coated electron microscope grid either dry or in a suitable liquid. If a liquid suspension is used in preparing the specimen, it is important that all elements of interest are insoluble in that liquid. Only particles thin enough to meet AEM thin-film criteria (15) should be analyzed quantitatively. Scraping surface particles from a catalyst pellet for specimen preparation may be more useful than grinding the entire pellet. 

Beef kidney samples were analyzed for atrazine by dispersing 0.5-g portions of kidney with 2-g portions of XAD-7 HP resin for matrix solid-phase dispersion. " By using a mortar and pestle, a powder-like mixture was prepared that was subjected to subcritical extraction using ethanol-modified water at 100 °C and 50 atm. The ethanol-water extract was sampled using a CW-DVB SPME fiber for direct analysis using ion-trap GC/MS, and the recoveries were quantitative for atrazine at the 0.2 mg kg fortification level. 

Char Preparatioa Chars were prepared both by isothermal pyrolysis of 5 g samples of resin in a quartz boat heated in an atmosphere of flowing (0.5 SCFM) N2 in a quartz tube oven (N2 pyrolysis chars) and by open combustion of 1 g samples of resin exposed to 2.8 watts/cm2 of radiant energy from an electric heating panel (4-5) (combustion or burn chars). All chars were finely ground with a glass mortar and pestle prior to analysis. 

Rust samples scraped off from exposed AISI 1019 steel surfaces were ground to fine size in a morter with a pestle. A fraction of the samples was subjected to a salts extraction process using distilled water to determine the concentration of most common ions by chemical analysis and to study changes in adsorption isotherm after elimination of hygroscopic salts. Samples were obtained from AISI 1019 steel coupons, exposed for up to six months at coastal and rural locations. 

The stoichiometry of the ground cocrystal material was confirmed by NMR and elemental analysis to be 1 1 0.5 (21 20 16). Interestingly, however, it was reported that a slight excess of BQ 21 was necessary to generate phase-pure material, in order to compensate for partial sublimation during the 60 min of manual mortar and pestle grinding. 

The first step in the procedure calls for weighing out some chocolate and extracting fat from it by dissolving the fat in a hydrocarbon solvent. Fat needs to be removed because it would interfere with chromatography later in the analysis. Unfortunately, if you just shake a chunk of chocolate with solvent, extraction is not very effective, because the solvent has no access to the inside of the chocolate. So, our resourceful students sliced the chocolate into small bits and placed the pieces into a mortar and pestle (Figure 0-1), thinking they would grind the solid into small particles. 

Coal and Ash Analysis. The coal and ash samples were separated into 20-40 g representative samples in the laboratory by a small riffle splitter. These samples were then pulverized with a mortar and pestle. The moisture content was determined by weighing the sample, drying it at 103 °C, and then reweighing it. These samples were kept in a desiccator and were subsequently used for the mercury analysis. 

All tooth and bone samples were initially prepared in the Laboratory for Archaeological Chemistry by the first author. Modem faunal samples for strontium isotope analysis were placed in a crucible and ashed at approximately 800°C for 10 hours. The bone samples were then crushed in an agate mortar and pestle. The teeth were removed from modem fauna mandibles after ashing and crushed and stored separately from the bone. 

Data preparation began by excluding any possibly unreliable and irrelevant data from the set of 33 elements. The heavy mineral solution could have imparted excess sodium (Na) and was thus ignored. The mortar and pestle used could have contaminated the aluminum (Al). Based on the hardness of the material and relative contribution to the sample this is likely not a significant problem however the role of Al was monitored closely during the data analysis. Previous literature on the geochemistry of specularite (10, 11) and preliminary... 

The substrate (10-20 mg, ca. 0.04 mmol) was coground with ca. 9.1 mg (0.04 mmol) of DDQ in a mortar with a pestle for about 10 min. The resulting colored solids were transferred to a small vial without a cap, and it was placed in a closed vessel, in which a shallow pool of methanol (1 mL) was maintained at the bottom. The vessel was kept in a refrigerator for 5-10 h. Product analysis was earned out by means of the ll NMR spectra for die sample after working up with a saturated NaHC03 solution. 

Montmorillonite K-10 (1 g) was mixed thoroughly with Fe(NC>2)3 -9H20 (0.404 g, 1 mmol) using a pestle and mortar. This mixture was added to neat tetrahydro-pyranyl ether 1 (1 mmol) in a beaker and was placed into a microwave oven (900 W). The mixture was irradiated for the indicated time. After completion of the reaction, which was monitored by TLC or GC, the crude product was extracted with dichloromethane. GC analysis of the crude product showed that 2 were obtained in high to excellent yields. Final purification was achieved by column chromatography using hexane-ethyl acetate as eluent. 

Preparation for X-ray Analysis. Lattice constants are calculated from patterns obtained on powder samples with a Norelco diffractometer using monochromatic radiation (AMR-202 Focusing Monochromator) from a high-intensity copper source. The crystals are powdered with a diamond mortar and pestle, and the powder passed through a 74-/ sieve. Accurate lattice constants are calculated from the x-ray data. 

Analysis of the essential oil content of seeds of certain cultivars, harvested at various stages of maturity and extracted by hydro-distillation from seeds that had been ground either in a pestle and mortar or a blender, indicated that the maximum yield of essential oil was obtained from ripening seeds (50% turning yellow). The use of a blender also increased the essential oil yield (Sanjeev et al., 1994). 

Separation and qualitative analysis of cations and anions test tubes, beaker, evaporating dish, funnel, watch glass, mortar and pestle, centrifuge, Pt or Ni test wire... 

Extraction of Cured, Modified Phenol-Formaldehyde Resins. A sample of the modified resin was spread as a thin coating on a sheet of aluminum foil and cured in an oven at 170 °C for 5 minutes. The cured resin was removed from the aluminum foil, weighed, and broken into small pieces that were placed in water (10 to 15 mL) for extraction at room temperature. After 1 to 2 hours, the water was decanted from the solid resin. The resin was extracted in this manner an additional three to four times. The residue from the water extraction at room temperature was dried and ground using a mortar and pestle. The ground resin was extracted with hot water in a Soxhlet apparatus for 24 hours. The room temperature extract and hot water extract were combined, concentrated, and diluted to a known volume for analysis. The quantity of modifier in the extract was determined by HPLC (77). 

Sample Preparation. Place sample in inert (glass or enamelled metal) pan or baking dish, and air-dry at ambient temperature. A fan may be used to hasten drying, but heat should not be applied. When sample just crumbles when touched, grind in mortar and pestle, quarter, and weigh for analysis. 

For chemical analysis of each sample, approximately 10 g of soil was transferred to a Gooch crucible. Surface debris such as twigs were removed, and the crucibles were heated in a muffle furnace at 500 °C for 24 h to remove organic components. The ashed soil was then pulverized with a pestle in a porcelain mortar. For each soil position, four 0.5-g portions of fine powder were analyzed separately, and the results were averaged. Soil analyses were performed in-house by atomic absorption spectrometry on a Varian Model 1250 spectrophotometer according to our previously reported method, which involves total dissolution of the sample in acid (11,12). The elements assayed were strontium, zinc, magnesium, calcium, sodium, lead, iron, aluminum, manganese, and potassium. 

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