Solid-Phase Reagents

THE SOLID-PHASE REAGENTS FOR THE DETERMINATION OF PHOSPHORUS AND ORGANIC REDUCTANTS... 

Unloaded silica does not recover HPA from aqueous solution. The surface of silica gel modified with quarternary ammonium salts (QAS) gets anion-exchange properties. The aim of the work is the elaboration of solid-phase reagents on the base of ion associate of HPA with QAS immobilized onto silica surface for the determination of phosphoms and organic reductants. Heterocyclic (safranine and lucigenine) and aliphatic (trinonyloctadecyl ammonium iodide and tetradecyl ammonium nitrate) compounds have been examined as QAS. 

Brombenztiazo (BBT) is known to be one of the best reagents for extraction-photometric determination of cadmium(II). The reagent also fonus complexes with Co(II), Cu(II), Fe(II), Ni(II), Zn(II). The aim of this work was to develop a solid-phase reagent on the base of BBT immobilized on silica gel for sorption-spectroscopic and visual test determination of Cadmium, and also for soi ption-atomic-adsoi ption determination of total heavy metals contents in natural waters. 

The research of congo red and stilbazo adsoi ption on aerosil is carried out. The test - techniques of hydrargymm and cupmm determination with the use of obtained solid phase reagents are designed. 

In the present work, the technique of XO and MTB immobilization onto silica gel in the form of its complexes with Fe(III) and Bi(III) respectively were found. The acid - base and chemical-analytical characteristics of solid-phase reagents were examined. The optimal conditions of quantitative recovery of Pb(II) and Zn(II) from diluted solutions, such as acidity of aqueous phase, the mass of the sorbents, the volume of solutions and the time of equilibrium reaching, were found. The methods of and F" detenuination were based on a competitive reactions of Zr(IV) with immobilized MTB and or F". Optimal conditions of 0,0 and F" determination in solution using SG, modified ion associates QAS-MTB (pH = 1,5, = 5-10 mol/1). 

It is known that Selenium catalyzes reaction of some dye reduction by Sulphide. On this basis spectrophotometric and test-techniques for Selenium determination are developed. Inefficient reproducibility and low sensitivity are their deficiencies. In the present work, solid-phase reagent on silica gel modified first with quaternary ammonium salt and then by Indigocarmine was proposed for Selenium(IV) test-determination. Optimal conditions for the Selenium determination by method of fixed concentration were found. The detection limit of Se(IV) is 10 ftg/L = 2 ng/sample). Calibration curve is linear in the range 50-400 ftg/L of Se(IV). The proposed method is successfully applied to the Selenium determination in multivitamins and bioadditions. 

Fig. 17 Rapid preparation of imidazoles and thiazoles on solid-phase. Reagents a RNH2, (CH30CH2)2, MW 220°C, 15min, closed vessel b TFA in CH2CI2, rt, 60min. R = aliphatic, benzyl, or arylamines or arylhydrazine...

Fig. 21 Microwave-promoted multicomponent synthesis of polysubstituted thiophenes on solid-phase. Reagents and conditions a RCOCH2R (R = H, Me, Et, Bn R = Me, i-Bu, i-Pn, Ph, Bn, cyclohexyl), Ss, DBU, toluene, MW 120 °C, 20 min, closed vessel, 100% b R"COCl (R" = Me, Pr, Ph or COOMe), diisopropylethylamine, toluene, MW 100 °C, 10 min, closed vessel c TEA, H2O, CH2CI2, rt, 2h...

Fig. 40 Microwave-assisted substitution of imidazole on C-2 in solid-phase. Reagents and conditions a benzaldehyde, N,N-diisopropylethylamine, CH2CI2, 24 h, rt b Nucleophile, TEA, Bp3Et20, THP, MW 120 °C, 5 min, closed vessel...

The packed bed reactor is particularly lu ul for reactions involving solid-phase reagents such as cati Psts, immobilized enzymes,and metallic reducing agents [641,642,646,647,658]. Since solutions are added in this isase, there are no... 

Barsukov V.Z., Khomenko V.G., Chivikov S.V., Barsukov I.V., Motronyuk T.I. On the faradaic and non-faradaic mechanisms of electrochemical processes in conducting polymers and some other reversible systems with solid-phase reagents. Electrochim. Acta 2001 46 4083-94... 

Here Ci0 = —is the solubility ci0 of the solid-phase reagents i normalized to... 

Another variation on the luminol CL sensor for N02 was introduced by Collins and Ross-Pehrsson [12] where a solid-phase reagent was positioned below a PMT, across which the air under test is pumped. Of the hydrogel or polymeric sorbents investigated, a Waterlock superabsorbing polymer (hydrogel)... 

The last of these systems has been adapted to a solid-phase reagent system (Equation 4.9) that obviates the problems associated with byproduct removal, and the by-product may be recycled (treatment with phosgene) to regenerate the active insoluble reagent.1819... 

Solid-phase reagents, 12 136 Solid-phase regrowth (SPR), in compound semiconductor processing, 22 190 Solid phases, soap, 22 728-731 Solid-Phase Synthesis database, 6 20 Solid polymer electrolyte (SPE) process,... 

Many of these have been discussed in the previous sections. Additional information about specific coupling chemistries for proteins can be found in the protocols and discussion regarding solid phase reagents (Matson, 2000). 

Matson, R.S., Solid-phase reagents, in Immunoassays A Practical Approach, Gosling, J.P, Ed., Oxford University Press, New York, 2000, chap. 5. 

The recent development of parallel and combinatorial chemical library synthesis has created a renewed interest in polymeric solid-phase reagents. They offer the advantage of... 

Scheme 23 Synthesis of optically enriched P-lactams through dual solid-phase reagents...

The combination of solution-phase with solid-phase reagents allows for the selective removal of excess reagents and/or by-products within a certain reaction containing a wide variety of functional groups.2,12,32 35 4 These... 

Two complementary methodologies were designed for rapid generation of libraries of 3,5-disubstituted 1,2,4-oxadiazoles from widely available carboxylic acids and amidoximes [93]. Both methods employed solid-phase reagents to simplify the purification process. Carboxylic acids were directly condensed with amidoximes in the presence of HBTU and an excess of PS-BEMP in acetonitrile (150 °C, 15 min). Alternatively, carboxylic acids were in situ converted to acid chlorides (with PS - PPI13/CCI3CN in THF) and subsequently reacted with amidoximes to furnish disubstituted oxadiazoles in good to excellent yields (Scheme 33). 

A derivative of umbelliferyl-p-galactoside serves as a fluorogenic substrate for E. coli (3-galactosidase in this system and solid-phase reagent strips based on this method have been developed. 

Walter, B. Greenquist, A.C. Howard, W.E., III. Solid-phase reagent strips for detection of therapeutic drugs in serum by substrate-labelled flourescent immunoassay. Anal. Chem. 1983, 55, 873-878. 

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