Sample collectors

Water Samples. Nine monthly MRR samples were collected at 11 sampling points throughout the pilot plant. The sample collector (Concentreur S656, SERES Co., Aix en Provence, France) enabled a composite sample to be collected over several days (8) and is based on adsorption of organics on resins (XAD-2 and XAD-8, Rohm and Haas). Factors that influence adsorption capacity in sampling were considered in the design of a two-bed resin column XAD-8 is more efficient to adsorb humic materials than XAD-2. Thus, an XAD-2 resin bed in series with an XAD-8 resin bed is appropriate to concentrate... 

Impact polystyrene with ignition-resistant additives is used for appliance housings, such as those for television and small appliances. Structural foam impact polystyrene modified with flame-retardant additives is used for business machine housings and m furniture because of its decorability and ease of processing. Consumer electronics, such as cassettes, reels, and housings, is a fast growing area for use of polystyrenes. Medical applicatiuns include sample collectors, petri dishes, and test lubes. 

A vapor detection sensor scheme for people or baggage is shown schematically in Fig 4, taken from Ref 12. As shown, air from the vicinity of the item or person being inspected is collected and delivered to a sensor, after first being conditioned. The sample collector can... 

Aromatic aldehydes (10 mmol) and trimethylorthoformate (20 mmol) was added to a mixture of sulfonamide (10 mmol), finely powdered calcium carbonate (9 g) and K-10 clay (2 g). The solid homogenized mixture was placed in a modified reaction tube which was connected to a removable cold finger and sample collector to trap the ensuing methanol and methyl formate. The reaction tube is inserted into Maxidigest MX 350 (Prolabo) microwave reactor equipped with a rotational mixing system. After irradiation for a specified period, the contents were cooled to room temperature and mixed thoroughly with ethyl acetate (2 x 20 mL). The solid inorganic material was filtered off and solvent was evaporated to afford tlie residue which was crystallized from the mixture of hexane and ethyl acetate. 

Mueller G, Norpoth K, Travenius SZM. 1981. Quantitative determination of bis(chloromethyl) ether (BCME) in the ppb range using portable air sample collectors. Int Arch Occup Environ Health 48 325-329. 

The equipment consisted of a microbalance suitable for thermogravimetric analysis (TGA), with an integral sample collector and an on-line gas chromatograph (GC) see Figure 1. Details of the apparatus have been presented before see e.g., Ref. 

The REY zeolite was pre-steamed at 500°C for 1 h. Approximately 5 mg of the catalyst was placed in the sample pan of the TGA microbalance, pretreated, and accurately weighed. Pretreatment consisted of heating at reaction conditions for 3 h. The external oven of the TGA was brought up to reaction temperature, 50O°C, and helium flow was started over the sample pan. Pulses of cumene and additive (if any), of nominal total mass 2 mg, were added to the stream. The valving was such that the outlet of the pulse passed through a sample collector. This was maintained at Liquid-nitrogen temperature, so that virtually all products could be collected, and only helium was... 

Their data suggest, however, that pesticide-laden dust in the atmosphere also must have been precipitated to earth by sedimentation and by rainfall. The average concentration found in the rainwater samples collected by exposing a sample collector for 1 month during the period November 1964 to February 1965 was for y-BHC 100, for dieldrin 20, and for p, p -DDT 3 parts per 1012 parts of rainwater (parts per trillion), whereas the samples collected only during periods of rainfall in January and March of 1965 averaged 29, 9, and 3 parts per 1012 parts of rainwater, respectively. 

Activity. We concentrate on the conversion of the "actual" feed reactant, cumene, as the measure of activity. We note how the conversion changes when different amounts of different coking additives (decane, naphthalene) are mixed with the feed, and pulsed over a catalyst of different coke levels. We also report data on the conversions of the additives decane or naphthalene under the same conditions. As mentioned earlier, cumene conversion is obtained by carrying out a benzene-ring balance on the contents of the sample collector after each pulse procedure, while conversions of naphthalene or decane are obtained by comparing peak areas with and without catalyst. 

The method shown in Figure 1.1 lb is not subject to this objection. If this method is not possible due to some obstruction, the ratio of stationary to moving time for the receiver should be made as large as possible. In many cases it is not possible to collect the whole of the stream, as this would give too large an amount to be handled. The best procedure is to pass a sample collector of the form shown in Figure 1.11c through the stream. 

The ion source and collector pieces were from the large (1200 mm) calutrons which were declared to have been in operation at Tarmiya. These graphite pieces were scraped with a razor blade to remove about one gram of powder from the surface which was then leached in nitric acid to dissolve the uranium. This was followed by isotopic measurements using a mass spectrometer at Seibersdorf s Safeguards Analytical Laboratory. Results showed that the ion sources sampled for analysis contained only natural uranium (see table 11.11). The data from the sampled collector pieces show enrichments not exceeding about 6%. 

With these methods and all others that sample from a moving stream of powder, the dimensions of the sample collector are important. The width of the receiver should be greater for smaller particles than for larger ones because of the tendency for fines to drift during the movement through air. To minimize error, the ratio of box width to particle diameter should be at least... 

Atmospheric deposition data, when available, are seldom directly suitable for comparison. Besides the general option to measure wet and dry deposition separately, one can choose to measure wet-only or total deposition (wet + dry). Furthermore, the shape of the sampling collectors, the additives to reduce algae growth and the use of acidified or distilled water as collecting medium are 3 main parameters which make comparison hardly possible. 

Fig. 4-9. Sample collectors for preparative vapor-phase chromatography.

Fig. 5.7. (A) Assembly used in the determination of cadmium and zinc in kidney and liver tissue by simultaneous microwave-assisted acid digestion of 6 samples, FI and AAS CT collector tube, FS flowing sample collector, R recorder. (B) Experimental design for the continuous microwave-assisted leaching, liquid-liquid extraction, sorption/clean-up of phenol compounds in soil samples IV, injection valve, PS membrane phase separator, o.p. and a.p. organic and aqueous phase, W waste. (Reproduced with permission of Elsevier.)...

Konorov SO, Zheltikov AM, Scalora M (2005a) Photonic crystal fiber as a multifunctional optical sensor and sample collector. Opt Express 13 3454—3459... 

In practice, solutions are first pumped into the test cell, and then circulated for a period of several hours to condition the membrane. Next, an electrolysis is performed to further condition the material. These solutions are then discarded, fresh catholyte and radioactive anolyte are added, and electrolysis is conducted at a given membrane current density. A sample of anolyte and the entire catholyte solution are then pumped to a sample collector for weighing and determination of radioactivity. Other experiments may then be repeated at other current densities, or the sequence repeated with new solution concentrations. Thus twelve different combinations of anolyte and catholyte concentrations are used. 

Figure 20 depicts the reaction data obtained from a proprietary reaction run in this fixed bed unit over a period of 7-8 hours. These graphs show the various gas and liquid flow rates, gas pressures at both the reactor inlet and the exit flow meter as well as the temperatures of the three reactor stages and the liquid level in the gas-liquid separator (GLS). The product composition is also measured by analyzing the samples taken by the automated sample collector. In this reaction, selectivity was a problem because of the formation of two byproducts. 

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