Instruction Sheets Post-column Derivatization User's Manuals and Instruction Sheets.
     
 

 

 

Reagent Bulletin for Post-column Liquid Chromatorgaphy 80

 

 


 

(DMAB; Ehrlich's Reagent)

Here you can download this materials in PDF format*

INTRODUCTION

For Post-column Analysis of Sulfa Drugs in Feeds

  • Chromatographic Grade® pure, colorless crystals

  • 450 nm detection for selectivity

  • Available in 5 gram bottles

Reversed-phase LC followed by post-column derivatization is used to determine the residue levels of Sulfamethazine, Sulfathiazole and related compounds in feeds and feed premixes. Although these compounds have a UV chromphore, so do most of the other constituents in a complex sample matrix. Forming a colored derivative post-column allows shifting of the detection wavelength into the visible range, thus greatly enhancing selectivity.

Pickering Laboratories Chromatographic Grade™ p-Dimethylaminobenzaldehyde

p-Dimethylaminobenzaldehyde (DMAB; Ehrlich’s Reagent) reacts rapidly with many primary amines to form a complex with maximum absorbance at 450 nm. Most commercially available grades are not of sufficient purity to operate in the demanding environment of post-column chemistry, as demonstrated by excessive baseline noise and shortened reagent life.

Pickering Laboratories’ highly purified, Chromatographic Grade DMAB, begins with the purest commercial grade available. The post-column reagent is prepared by dissolving DMAB in glacial acetic acid, methanol and water2:

  • DMAB 1.5 g

  • Acetic acid 100 mL

  • Methanol 60 mL

  • Water 40 mL

 

DMAB 4-Dimethylamiobenzaldehyde
CAS No. [100-10-7]

By maintaining the prepared reagent under inert gas, and in a reservoir fitted with oxygenimpermeable tubing, it is possible to extend its effectiveness for up to one week.

The Pickering Laboratories AO3100 derivatization instrument (with a special 0.5 mL reactor) may be connected to a standard liquid chromatograph (HPLC) with a UV/Vis detector, to convert it to an analyzer specific for the analysis of sulfa drugs.

References

  1. R.W. Stringham, E.C. Mundel and R.L. Smallidge, JAOAC, 1982, 65.(4), 823–827.

  2. R.C. Smallidge, E.J. Kentzer, R.W. Stringham, et al., JAOAC, 1988 71(4), 418–453.

  3. L.V. Bui, JAOAC, 1993, 76(5), 966.

ORDERING INFORMATION

CATALOG NO.

DESCRIPTION

3700-0400

p-Dimethylaminobenzaldehyde

 

 

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