Onyx PCX Post-Column Derivatization Instrument for HPLC

Onyx PCX Post-column derivatization instrument for HPLC, is the only instrumentation optimized for the analysis of amino acids, carbamates, glyphosate, mycotoxins, antibiotics and many other applications,  specifically designed to enhance sensitivity and selectivity.   The Onyx PCX reflects the ease of use, reliability and ruggedness and is trusted by agencies such as EPA, ATF, FDA and many other industries.

  • More than 30 years of Post-Column Brilliance
  • Guaranteed Chemistry through validated methods
  • Works with all HPLC systems
  • Complies with EN 61326-1

Available with one or two reagent pumps, Onyx PCX instrument layout is focused on ease-of-use, quick monitoring and rapid service. The electronic syringe pump provides true pulse-free flow for superior sensitivity and consistency.  The pump’s cylinder and head are made from a single piece of  99.9% Alumina for ruggedness and non-reactivity. An automatic piston wash and programmable system flush mechanism ensure that the delivery pumps can always be kept clean. All fluidics are located on front panel for instant access and easy leak checks with a drip tray included.  Integrated gas manifold allows to pressurize the reagents protecting them from oxidation and an air barrier tubing protects the post-column reagent from oxidation.

Why Post-column Derivatization?

Improves sensitivity

  • Used for compounds with no fluorescence or weak UV absorptionl
  • Post-column reaction produces a fluorescent or colored derivative that is easily detected

Improves selectivity

  • Post-column reagent is specific for analytes of interest, so matrix components do not interfere with detection

Matrix-independent analysis

Derivatization occurs after the analytes are separated on the column, so the chemical reaction is not affected by other compounds in the sample matrix

Quick-change reactor cartridges make application switching easy and replacements fast and inexpensive. The temperature range holds within 1°C resolution from 5°C above ambient room temperature to 130°C maximum setpoint.  The column heater utilizes recirculating airflow technology and temperature range holds within 1°C resolution from 5°C above ambient to 75°C maximum setpoint.


Column oven temperature gradient programming improves separation and run times. Only Pickering Laboratories builds post-column systems with this feature which helps reduce amino acid analysis run times. Metabolic markers such as Alloisoleucine (MSUD) and Argininosuccinic acid (ASA) which under isothermal conditions coelute with Cystathionine and Cystathionine, are well resolved using a targeted temperature gradient program in the Onyx PCX.