Preparation in acetone

All primary amines react with fluorescamine under alkaline conditions (pH 9-11) to form a fluorescent product (Figure 10.12) (excitation maximum, 390 nm emission maximum, 475 nm). The fluorescence is unstable in aqueous solution and the reagent must be prepared in acetone. The secondary amines, proline and hydroxyproline, do not react unless they are first converted to primary amines, which can be done using A-chlorosuccinimide. Although the reagent is of interest because of its fast reaction rate with amino acids at room temperature, it does not offer any greater sensitivity than the ninhydrin reaction. 

Reagents, (a) Pesticide standards of acephate, bromopropylate, chlorpyrifos, chlorpyrifos-methyl, chlorothalonil, diazinon, dichlorvos, endosulfan I, endosulfan II, endosulfan sulfate, lindane, methamidophos, phosalone, procymidone, pyrazophos, triazophos, and vinclozoline (purity >98%) were supplied by Riedel de Haen (Seelze, Germany). For each pesticide, a stock standard solution (about 500 mg/L) was prepared in acetone. Spiking standard solution, containing 50 mg/L of each pesticide, was prepared in acetone from the stock standard solutions. 

The epoxidation of heteroarenes such as furans and indoles generates very labile products, such that the reaction needs to be carried out at subambient temperature. For example, even at —20°C, the epoxide of 2,3-drmethylbenzofuran rearranges to the ortho-quinomethide (equation 5) . To characterize this epoxide by H-NMR spectroscopy, the fully deuteriated DMD-dg solution, prepared in acetone-dg, was employed for the oxidation and the epoxide was detected at —78 °C . Alkynes lead on epoxidation to a multitude of oxidation products (equation 6) thus, the reaction is synthetically hardly useful and, therefore, has been little studied . ... 

Fluorescamine reacts instantaneously with the primary amino groups of peptides, yielding a fluorescent product with an excitation peak at 390 nm and an emission band at 475 nm. It is insoluble in water and is usually prepared in acetone. Neither the reagent nor the degradation products of the excess reagent in an aqueous medium are fluorescent, which is a great advantage, particularly when postcolumn derivatization is used. 

No product was obtained when attempts were made to copolymerize styrene and maleic anhydride in benzene at 50° C in the absence of bis-azoisobutyronitrile. Likewise, no free radicals were detectable when these solutions were examined using EPR techniques. Negative results were also noted in solutions of the alternating copolymer prepared in acetone. However, the presence of free radicals was noted when the alternating copolymer produced by heterogeneous solution polymerization in benzene was examined. This peak was observed with freshly prepared and aged copolymer samples that had been stored in an inert environment. However, no peak was observed in product that had been washed with methanol. 

Preparation of N-(3-chloropropyl)-N -[2-(l,3-dioxanyl)-ethyl]-piperazine A solution of 30 g (0.15 mol) of N-[2-(l,3-dioxanyl)-ethyl]-piperazine and 11.8 g (0.075 mol) of l-bromo-3-chloropropane in 150 ml of dry benzene was refluxed with stirring for 5 hours. After cooling, the N-[2-(l,3-dioxanyl)-ethyl]-piperazinium bromide which had precipitated was filtered off, the filtrate was concentrated in vacuo and the residual oil was distilled. 14.1 g (68%yield) of N-(3-chloropropyl)-N -[2-l,3-dioxanyl)-ethyl]-piperazine which occurred as a light yellow oil were obtained. Boiling point 152°C to 155°C under 0.07 mm Hg (nD23 = 1.49 40). The disuccinate prepared in acetone and recrystallized from acetone melts at 104°C to 105°C on a hot stage microscope. 

Figure 4. XRD Pattern of Au-Sn Powder Prepared in Acetone. Ratio of Au Sn Evaporated is 1.3 1.

Figure 5. XRD Pattern of Au-Sn of Powder Prepared in Acetone by evaporating Each Metal Successively (layering experiment).

Figure 7. X-Ray Diffraction Pattern of a AuSn Sample (prepared in acetone) Heated to 275 C Under Argon.

Figure 9. DSC spectra of AuSn particles prepared in acetone by (a) fast warm-up (b) slow warm-up...

Figure 10. 119Sn Mossbauer Spectra for (1) j3-Sn foil (2) bulk AuSn alloy (3) Sn particles prepared in acetone (4) AuSn particles prepared in acetone...

Table HI. XPS of AuSn Particles Prepared in Acetone Binding Energies in eV...

Figure 11. Gold XPS Valence Band Spectra of (1) Bulk gold (2) AuSn particles prepared in acetone (3) after Ar ion etching.

Fe(CO)cp(H)(SiCl3)2 is a very strong acid in acetonitrile its pKa value of 2.6 shows it to be stronger than HBr or H2S04 in this solvent, but weaker than HC104. A tetraphenylarsonium salt can be prepared in acetone ... 

A standard solution of an Internal standard (dodecane or hexadecane) is also prepared in acetone. This solution should be at the same concentration as that of the sulfide. 

Among other impuritiee. ketene dim prepared in acetone eolu-tion can contain acetic anhydride formed by the accidental hydro lyric of Ihe monomer This product, iriiich can be determined by infrared spectrophotometiy, ib eeparafed by distillation,preferably below BO-ioo followed by fractional oryetaUixa-... 

Suspensions of HTSC for the electrophoretic deposition of bismuth [403-409] and thallium [403] HTSC, various cuprates of rare-earth metals and barium [204, 407,410-414], and also silver HTSC [415,416] and PbO-HTSC [417] compositions have been used. These are prepared in acetone, acetonitrile, toluene, butanol, methylethylketone, or mixed solvents. They contain chemically pure materials (silver is introduced as AgaO) dispersed thoroughly, first mechanically and then in liquid) by ultrasonic treatment (in which case the particles became charged). The choice of solvent is by and large determined by its effect on the stability of the deposited oxide [417]. 

The CAD in the surfactant micelle was prepared by spreading 1 mL of 1 mmol/L dye solution (prepared in acetone) to each 50 mL Pyrex glass tube and air-dried so that the dye was evenly coated onto the tube wall. Various amounts of stock surfactant solution and additives (if any) were added to each tube and diluted by distilled and deionized water to a predetermined concentration with a final volume of 25 mL. Samples were then mixed with the solution, sealed with a Teflon-lined screw cap, and shaken in a mechanical rotary shaker at 20°C for 24 hrs. Different initial pH levels were adjusted by sulphuric acid or sodium hydroxide so that the consequence of initial pH to the overall reaction rates can be realised. 

Kunitake and Tsukino ( 0 also used 13c NMR to determine ring size in the copolymer, but they calculated chemical shifts by extrapolating published data on simpler cyclic compounds. By this method they concluded that a copolymer prepared in chloroform contained only tetrahydrofuran rings. However, their published spectrum of the copolymer contained the same peak B as ours, and therefore the copolymer must consist of both five- and six-membered rings. The spectrum of a copolymer prepared in acetone-carbon disulfide was too poorly resolved to show peak B, but Kunitake and Tsukino estimated the polymer to contain about 90% tetrahydropyran rings. 

Effect of Concentration and Formulation. Moist CHECK soil (26.4% moisture, 30 g oven-dry weight) was treated with technical grade alachlor (prepared in acetone) or an emulsifiable concentrate formulation (Lasso 4EC, 45.1% a.i., prepared in water) to yield application rates of 10, 100, and 1000 ppm soil. Stock solutions of alachlor were prepared by mixing the appropropiate amount of either the technical grade or emulsifiable alachlor with 2.6 (XCi of uniformly ring-labelled 14C alachlor (Monsanto Co., specific activity=13.74 mg/mCi, radiochemical purity=95%). 

The ruthenium catalyst of the type RUCI3L2 were prepared in acetone. The Schiff bases wee prepared according to literature procedures[6-8]. Methanol, acetone an DMF were purified according to literature methods[9]. 

Viscosity Measurements. Solution viscosity data were obtained with the use of a Cannon-Fenske viscometer (size 50) at 25°C. Solutions were prepared in acetone (0.30 g/100 mL). 

Test Chemicals. Stock solutions of the desired concentrations of test chemicals were prepared in acetone. The final concentration of the solvent was held constant at 1% (v/v) in all assays including the controls. Data presented for the several studies were averaged from determinations made with a minimum of three separate replications and isolations. 

Leaf Disc Fluorescence. Discs or leaf pieces approximately 10 mm in diameter were cut from recently unfolded soybean trifoliates or fully expanded mustard leaves. Inhibitor stock solutions were prepared in acetone. Discs were floated abaxial side downward in solutions containing water, 0.3% acetone, 0.05% Tween 20, and 10 pM atrazine, diuron or LY181977. After 150 min. incubation, each disc was removed from the soaking solution, blotted dry and the adaxial side of the disc was placed under the probe of a Model SF-20 Brancker Plant Productivity Fluorometer for 10 s in the dark followed by 10 s of illumination. 

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