A new direct inlet probe system for liquid chromatography

With the new direct inlet probe system (DIP) the field for all Agilent LC/MS instruments is enlarged noticeably. The direct inlet probe system is based on an APCI source (atmospheric pressure chemical ionization), that means the ionization is made by a corona discharge under standard APCI conditions. Liquid or solid samples can be inserted directly into the ion source without a previous chromatographic seperation. In combination with a high resolution mass spectrometer the DIP-APCI source makes e.g. a fast quality control of substances with a complex matrix possible, without time-consuming sample preparation.


At existing direct analysis systems for atmospheric pressure ion sources a non-specific ion formation of complex samples appears; because of numerous ion molecule reactions in the ion source, it comes to ion suppression and artefact formation. The decisive innovation of the DIP-APCI source lies in the temperature programmable push rod tip with which the analysis substance is vaporized (heating rates of 0,1-2°C/s in a temperature range of 30-400°C) in front of the corona needle. Due to different steam pressures of the analytes it comes to a staggered ionization so that the ion formation gets more specific by reduction of matrix effects.

Another advantage is due to the construction of the direct inlet probe system (DIP): Without a conversion process of the LC/MS System, the measurements can be switched from DIP-APCI/MS to LC/APCI/MS without any problems. And in combination with an autosampler for liquid and solid samples, the effectiveness can be increased for fast screenings.

In 2012 first applications were published with pharmaceutical products with this system and reproducibility tests were carried out by using Chinese medical herbs (S. Krieger, A. von Trotha, K. S.-Y. Leung, O. J. Schmitz, Development,optimization, and use of an APCI source with temperature-controlled vaporization of solid and liquid samples, Anal Bioanal Chem DOI 10.1007/s00216-012-6531-4).

Main fields of application of the DIP APCI are food control, product control of the pharmaceutical and chemical industry and the Metabolom research because also very small sample amounts can be analyzed without thinning. In future, this already commercial ion source also will have the possibility of the ionization  with atmospheric pressure photon ionization (APPI) besides APCI. Further information about the field of application as well as the development of the DIP APCI system is described in the article of Labor Praxis "A new ion source for product control ".



  • Direct inlet probe system (DIP) for liquid and solid samples
  • automatic insertion of the samples into the APCI-source
  • fast switching from DIP-APCI/MS to LC-APCI/MS-measurements
  • convenient operation via DIP-software (temperature program for push rod heating) and Agilent software (spectral processing)
  • for fast screenings
  • upgradeable with PAL autosampler for automation and online analysis (of liquid and solid samples)
Article Order no.
Direct-Inlet-Probe System (DIP) incl. APCI-source for an Agilent LC/MS Series 6000 System B 0600 60 00

pdf Brochure DIP-APCI for LC/MS.pdf


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