NEW C H E M I C A L S
A NEW GENERATION of d e r i v a t i z i n g
Derivatizing Agents A new family of reagents for the acylation or silylation of samples to produce derivatives for GLC, mass spectrometry, and synthesis, recently introduced consists of JV-heptafluorobutyrylimidazole (HFBI), iV-trifluoroacetylimidazole (TFAI), JV-trimethylsilylimidazole (TSIM), and JV-acetylimidazole. A highly pure and stable form of ^V'-carbonyldiimidazole is also offered. The fluorinated acyl de rivatives are ideal for flame detectors and highly sensitive to electron capture. Pierce Chemical Co., P. O. Box 117, Rockford, 111. 61105 501
New Line of Standardized Materials A comprehensive line of 900-plus Specpure ® spectrographically stan dardized substances covering some 70 elements is now available in this country for use as reference standards and for making standard mixtures. Specpure® standards from Fisher, packaged for purity and stability, are offered in a.variety of forms, including rod, sheet, wire, sponge, powder, grain, lump, and crystal. A bulletin of infor mation on the entire line can be ob tained from Fisher Scientific Co., 312 Fisher Bldg., Pittsburgh, Pa. 15219 502
New Agarose Gel Sepharose 6B is a 6% beaded agarose gel manufactured from the neutral por tion of agar. Tt increases the resolving power of the gel filtration method for the separation and fractionation of molecules within the molecular weight range of ca. 500,000 to one million. Pharmacia Fine Chemicals, Inc., 800 Centennial Avenue, Piscatawav, N. J. 0S854 503
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agents
-Heptafluorobutyryl ^ H CF3CF2CF2C(=0)— N-Trifluoroacetyl CF3C(=0)N-Trimethylsilyl
(CH s ).,Si—I
CHaC(=0)N-Acetyl Also highly pure and stable Ν,Ν'-CARBONYLDIIMIDAZOLE For ACYLATION or SILYLATION of samples to produce ideal derivatives for GLC, Mass Spec and for Synthesis. SMOOTH, POSITIVE, SOMETIMES SELECTIVE. The N-Acyl imidazoles offer considerable advantage over methods using acid chlorides or anhydrides. No acids are released in the system and relatively inert imidazole is the by-product. The fluorinated acyl derivatives are ideal for flame detectors and are quite sensitive to electron capture, especially the hepta fluorobutyryl. The HFBI and TFAI will acylate hydroxyl groups and both primary and secondary amines. Trimethylsilylimidazole (TSIM) reacts quickly and smoothly with hydroxyl groups onlyi.2 to produce vola tile and thermally stable TMS ethers. Most useful in car bohydrate chemistry, TSIM is also finding applications with alcohols and phenols, Amino acids, organic acids, hydroxyamines, steroids, flavonoids, glycols, nucleotides, hydroxy acids, barbiturates and narcotics. Birkofer and Ritter3 have reviewed a number of unique synthetic pos sibilities of this interesting reagent; for instance, the reaction with thionyl chloride to form thionyl diimidazole and with PCla to form triimidazolyl phosphine.
are silylated with TSIM, then the amino groups are acylated with HFBI, producing the excellent and dis tinctive 0-TMS.N-HFB derivatives for either f.i.d. or e.c. detection. Please Order as Follows: No. 44210 N-Heptafluorobutyrylimidazole (HFBI) $15/5g; $60/25g. No. 48882 N-Trifluoroacetylimidazole (TFAI) $15/5g; $60/25g. No. 88623 N-Trimethylsilylimidazole (TSIM) $14/10g; $27/25g. No. 90148 N-Acetylimidazole $16/25g; $48/100g. No. 31592 Ν,Ν'-Carbonyldiimidazole $36/25g; $108/100g. References cited: 1. M. G. Horning, A. M. Moss, and E. C. Horning, Biochim.Biophys.Acta 148, 597-600 (1967). 2. M. G. Horning, A. M. Moss, E. A. Boucher and E. C. Horning; Analytical Letters, 1(5), 311-321 (1968). 3. L. Birkofer and A. Ritter, "New Methods of Prepara tive Organic Chemistry," Vol. IV, Academic Press, New York-London.
Horning, Moss, Boucher and Horning2 have ingeniously demonstrated the sequential use of two of these re agents in a single reaction mixture in preparing catechol amines for GLC and Mass Spec. First, all hydroxyl sites
PIERCE CHEMICAL COMPANY P. O. Box 117 Rockford, I l l i n o i s PHONE 815/968-0747
TWX
61105
910-631-3419
Circle No. 60 on Readers' Service Card
We've got more NMR Solvents to choose from! Take your pick of the best. The choice should be easy ; there are n o w 67 deuterated solvents and standards for NMR with the EM-Reagents label...the largest selection available. Find the ones y o u need or w o u l d like to try in our complete catalog of EM analytical chemicals. For your free c o p y , just write: EM-Reagents Division, Brinkmann Instruments, Cantiague Road, Westbury, N.Y. 11590. ADIVISIONOF
EM-Reagents BRINKMANN
Steroid Silylating Agent A new set of reagents for selectively silylating steroids is now available for preparing volatile derivatives of ster oids and related compounds for gas phase analysis. A kit is offered con taining all the reagents plus three use ful silylation grade solvents. Pierce Chemical Co., P. O. Box 117, Rockford, 111. 61105 504 Circle No. 102 on Headers' Service Card
VOL. 4 1 , NO. 6, MAY 1 9 6 9
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131 A
