Solid dilution method

Solid dilution method 8 Appendix British Standards... 

A reference solution is prepared by a dilution method. A known quantity of sample is dissolved in a known volume of the system buffer of known pH the amount of sample is X times less than in the above case in order to avoid precipitation in the formed solution. The spectrum is immediately taken by the UV spectrophotometer, to take advantage of the possibility that solution may be supersaturated (i.e., solid should have precipitated, but because not enough time was allowed for the solid to precipitate, the solution was temporarily clear and free of solid). Mathematical treatment of the spectral data yields the AUC of the reference sample solution, AUQ . The ratio R = AUCS/AUCS is used to automatically recognize the right conditions for solubility determination when the reference has no precipitate, and the sample solution is saturated with precipitate. Under these conditions, solubility is determined from the expression... 

The following characteristics were analysed by standard methods (9) TS, volatile solids (VS), chemical oxygen demand (COD), Kjeldahl nitrogen (Kj-N) and ammoniacal nitrogen (NH3-N). The biochemical oxygen demand of whole slurry (BODw) was analysed by a dilution method (10). Volatile fatty acids (VFA) were analysed by gas... 

Barker SA, Littlefield-Chabaud MA, David C. 2001. Distribution of the hallucinogens N,N-dimethyltryptamine and 5-methoxy-N,N-dimethyltryptamine in rat brain following intraperitoneal injection application of a new solid-phase extraction LC-APCI-MS-MS-isotope dilution method. J Chromatogr B Biomed Appl 751 37. 

Waters, soils, sediments, sludges <30% solids Dilution to 1% solids and extraction with methylene chloride, concentration using K-D. Clean up using GPC and SPE. GC/FPD (Method 622) 3.8 ng/L 60-120 EPA 1992c... 

Bayer et al. used mass spectrometry to detect the formation of failure sequences in the solid phase method 16). Mass spectrometric dilution assay coupled with Edman... 

Solids flux method. The design of the thickener area considers zone C. (Note you do not consider zone D.) As indicated, the concentration of the solids in this zone is variable. Thus, the behavior of the solids is modeled by making several dilutions of the sludge to conform to the several concentrations possible in the zone. The ultimate aim of the experiment is to be able to determine the solids loading into the thickener. The experiment is similar to that of the clarifier design, except that several concentrations are modeled in this instance. Also, it is the relation between subsidence velocity and concentration that is sought. The reason is that if velocity is multiplied by the concentration, the result is the solids loading called the solids flux, the parameter that is used to size the thickener portion. 

The interest of the dilution (in liquid phase) or fusion (in solid phase) methods is to make the coefficient p independent of the initial composition of the sample. 

Catalysts with a high loading of impregnated metals, such as Ni-Mo and Co-Mo on alumina hydrotreatment catalysts, necessarily suffer from matrix modifications with variations in metal content. As wc are not limited in this instance by the need to analyse trace elements, the solid phase dilution method can be used to attenuate the matrix effects. 

The dilution method is not suitable for use with Zasoski and Burau (1978)-type batch reactors, because the solid and solution phases must be separated, so that the fraction of the solution phase can be replaced, and then the phases are remixed. Flow methods are of course readily suited for use with the dilution technique, because the input solution can be easily replaced with an identical solution without the solute of interest, and then desorption occurs during continuous flow. 

R. Tertian, A rapid and accurate x-ray determination of rare earth elements in solid solution on liquid materials using the double-dilution method, Adv. X-ray Anal, 72 546(1969). 

For soluble polymers, comparison with their solution spectra offers the simplest means to assign the resonances in their CPMAS/DD solid-state spectra. On the other hand, those polymers that cannot be dissolved, melted or sufficiently swollen to provide high-resolution liquid-state spectra for comparison, can be observed in the solid with methods comparable to those developed for editing solution-state spectra. It is easier to describe these methods with the aid of a qualitative understanding of how the dilute C and abundant spins interact in a typical solid, organic sample. 

An isotope dilution method with an ICPQMS equipped with direct reaction cell (DRC) to remove interferences from polyatomic ions was described (Kimnan et al. 2009). A nebulizer suitable for high solids introduction was used for measurement of urine samples that were diluted fivefold with 10% nitric acid. Isotope ratios were precisely determined for urine sample that contained >54 ng L . A three-stage rinsing procedure was run between samples to minimize salt deposition, memory effects, and instrumental drift. 

There are two methods of effecting spreading of protdns on aqueous surfaces. Hughes and Rideal (5), Hughes (6), Fosbinder and Lessig (7) found that solid particles, even of water insoluble protdns, spread very rapidly when carefully placed on the surface. The amount of material spread is determined by a modified Nemst balance. The other method which has several advantages over the solid particle method is to drop on the clean aqueous surface a dilute solution of the protein. It is very important that the protein solution be quite dilute but it is difScult to set... 

Tertian, R., 1969, A Rapid and Accurate X-ray Determination of the Rare Earth Elements in Solid or Liquid Materials Using the Double Dilution Method, in Barrett, C.S. et al., eds.. Advances in X-ray Analysis, Vol. 12 (Plenum Press, New York) pp. 546-562. 

The solids diluted in KBr or in the form of films present difficulties in the measurement of its thickness. In this case, an internal standard is used that consists of adding a known quantity of a material that is not present in the sample and that does not interact with it. The internal standard must be pure, have an intense band, be well resolved, and not interfere with the analytical band. The concentration is obtained directly, as long as the absorptivity and the optical pathway are known. Another widely used method is the calibration curve, suitable for cases where the concentration of the sample varies within a wide range of limits. 

The residue in the flask will contain the sodium (or potassium) salt of the acid together with excess of alkali. Just acidify with dilute sulphuric acid and observe whether a crystalline acid separates if it does, filter, recrystallise and identify (Section 111,85). If no crystaUine solid is obtained, the solution may be just neutralised to phenolphthalein and the solution of the alkali salt used for the preparation of a crystaUine derivative. This wiU confirm, if necessary, the results of hydrolysis by method 1. If the time factor is important, either method 1 or the product of the caustic alkali hydrolysis may be used for the identification of the acid. 

Method 1. Place in a test-tube or small flask 1-3 g. of glycerol and 30 ml. of 10 per cent, sodium hydroxide solution add gradually, with simultaneous shaking, 1-2 g. of benzoyl chloride. Stopper the vessel, shake for several minutes and allow to stand. Decant the solution from the pasty solid and wash the latter with cold water by decantation. Recrystallise the solid tribenzoate from dilute rectified (or methylated) spirit or from light petroleum, b.p. 40-60° the pure compound has m.p. 76°. 

The sulphonanilldes may be prepared by either of the following methods —(i) Reflux the solution of the sulphonyl chloride in benzene obtained as above, with 2 5 g. of aniline for 1 hour. Concentrate the benzene solution to half its volume and cool in ice. Collect the solid which separates on a filter, wash with hot water, and recrystallise from ethanol or dilute ethanol. 

Method 1. Treat 2 0 g. of the mixture of amines with 40 ml. of 10 per cent, sodium hydroxide solution and add 4 g. (3 ml.) of benzenesulphonyl chloi de (or 4 g. of p-toluenesulphonyl chloride) in small portions. Warm on a water bath to complete the reaction. Acidify the alkaline solution with dilute hydrochloric acid when the sulphonamides of the primary and secondary amines are precipitated. Filter off the solid and wash it with a little cold water the tertiary amine will be present in the filtrate. To convert any disulphOnamide that may have been formed from the primary amine into the sulphonamide, boil the solid under reflux with 2 0 g. of sodium dissolved in 40 ml. of absolute ethyl alcohol for 30 minutes. Dilute with a little water and distil off the alcohol filter off the precipitate of the sulphonamide of the secondary amine. Acidify the filtrate with dilute hydrochloric acid to precipitate the derivative of the primary amine. Recrystallise the respective derivatives from alcohol or from dilute alcohol, and identify them inter alia by a determination of the m.p. 

Method 2. Place a 3 0 g. sample of the mixture of amines in a flask, add 6g. (4-5 ml.) of benzenesulphonyl chloride (or 6 g. of p-toluenesulphonyl chloride) and 100 ml. of a 5 per cent, solution of sodium hydroxide. Stopper the flask and shake vigorously until the odour of the acid chloride has disappeared open the flask occasionally to release the pressure developed by the heat of the reaction. AUow the mixture to cool, and dissolve any insoluble material in 60-75 ml. of ether. If a solid insoluble in both the aqueous and ether layer appears at this point (it is probably the sparingly soluble salt of a primary amine, e.g., a long chain compound of the type CjH5(CH2) NHj), add 25 ml. of water and shake if it does not dissolve, filter it off. Separate the ether and aqueous layers. The ether layer will contain the unchanged tertiary amine and the sulphonamide of the secondary amine. Acidify the alkaline aqueous layer with dilute hydrochloric acid, filter off the sulphonamide of the primary amine, and recrystaUise it from dilute alcohol. Extract the ether layer with sufficient 5 per cent, hydrochloric acid to remove all the tertiary amine present. Evaporate the ether to obtain the sulphonamide of the secondary amine recrystaUise it from alcohol or dilute alcohol. FinaUy, render the hydrochloric acid extract alkaline by the addition of dilute sodium hydroxide solution, and isolate the tertiary amine. 

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