Gerstel MCS Multidimensional Chromatography System

Overview

The Gerstel MCS Multidimensional Chromatography System is an engineered solution for comprehensive separation of complex hydrocarbon mixtures and trace volatile organic compounds (VOCs) in petrochemical matrices. Unlike conventional single-column gas chromatographs, the MCS implements heart-cutting (GC-GC) and comprehensive two-dimensional gas chromatography (GC×GC) configurations via precisely timed, pneumatically actuated column switching—enabled by GERSTEL’s proprietary EPC (Electronic Pressure Control) architecture. The system operates as a modular add-on to existing Agilent 7890/8890 series GC platforms, preserving native instrument firmware while extending analytical capability through cryogenically enhanced trapping, low-dead-volume GRAPHPACK™ column interconnections, and synchronized valve sequencing. Its core function is to isolate co-eluting analytes from congested sample regions—such as gasoline distillates, refinery streams, or polymer degradation volatiles—and transfer them onto a secondary column with orthogonal selectivity (e.g., polar/non-polar phase pairing), thereby resolving structural isomers and trace contaminants below 10 ng/g detection thresholds.

Key Features

• Modular, non-invasive integration with Agilent GC platforms—no hardware modification required to host GC or detector.
• Dual independent EPC modules for real-time pressure and flow regulation on both primary (pre-column) and secondary (analysis column) circuits—ensuring retention time stability ±0.02 min over 48-hour sequences.
• Cryogenic trapping unit (-40 °C to +10 °C range) with programmable thermal desorption, enabling focused band re-injection and signal enhancement for C₂–C₁₂ compounds.
• GRAPHPACK™ zero-dead-volume connection system using metal-sealed ferrules and pre-aligned graphite sleeves—validated to eliminate leakage at pressures up to 100 psi and temperatures up to 400 °C.
• Automated heart-cut scheduling via MAESTRO software: user-defined retention windows trigger valve actuation within ±10 ms timing accuracy.
• Support for multiple column chemistries: DB-1/DB-5, DB-WAX, CP-Sil 8 CB, and custom-packed capillary columns (0.10–0.53 mm ID, 10–60 m length).

Sample Compatibility & Compliance

The MCS system accommodates liquid, gaseous, and headspace-derived samples introduced via GERSTEL’s CIS-4 cold injection system, MPS XT robotic autosampler, or TDS3 thermal desorption unit. It meets method requirements for ASTM D6729 (determination of hydrocarbon types in gasoline), ISO 15503 (ambient air VOC monitoring), and USP residual solvent analysis. All valve actuation events, temperature setpoints, and EPC parameters are logged with timestamped, user-identifiable entries—fully compliant with FDA 21 CFR Part 11 electronic record integrity standards. Audit trails support GLP and GMP laboratory inspections, including full traceability of method changes, calibration history, and sequence execution logs.

Software & Data Management

Control and method development are performed exclusively through MAESTRO software (v2.5 or later), a Windows-based platform certified for regulated environments. MAESTRO provides synchronized control of GC oven, inlet, detector, MCS valves, and cryotrap—all within a single workflow interface. Method templates include built-in validation checks for valve timing conflicts, pressure imbalance warnings, and trap desorption overlap detection. Raw data files (.D format) are stored in vendor-neutral HDF5 containers, supporting third-party processing via OpenChrom or Chromeleon. Batch processing includes automated peak table generation, retention time locking (RTL), and spectral deconvolution for co-eluted peaks using AMDIS-compatible libraries.

Applications

• Petrochemical QA/QC: Speciation of olefins, dienes, and aromatics in FCC naphtha and reformate streams.
• Fuel analysis: Quantification of benzene, toluene, ethylbenzene, xylenes (BTEX), and oxygenates per EN 228 and ASTM D4814.
• Polymers & additives: Identification of catalyst residues, plasticizers (e.g., phthalates), and thermal degradation markers in polyolefins and elastomers.
• Environmental forensics: Target/non-target screening of alkylbenzenes, PAHs, and chlorinated solvents in soil extracts and groundwater concentrates.
• Flavor & fragrance profiling: Separation of stereoisomeric terpenes and lactones in essential oils where single-dimension GC fails.

FAQ

Can the MCS operate independently without an Agilent GC?
No—the MCS is not a standalone chromatograph; it requires integration with an Agilent 7890B, 8890, or 8860 GC platform to provide oven temperature control, detector synchronization, and data acquisition.
Does the system support comprehensive two-dimensional GC (GC×GC)?
Yes—when configured with dual modulators and appropriate column sets, the MCS enables true GC×GC operation with modulation periods from 2–10 seconds, compatible with flame ionization (FID) and mass spectrometric (MS) detection.
Is MAESTRO software validated for pharmaceutical use?
Yes—MAESTRO v2.5+ includes 21 CFR Part 11-compliant features: electronic signatures, role-based access control, audit trail export, and secure user authentication protocols.
What maintenance intervals are recommended for the cryotrap and EPC modules?
GERSTEL recommends quarterly verification of cryotrap cooling performance and annual recalibration of EPC pressure sensors using NIST-traceable reference gauges.
Can I retrofit an older Agilent 7820A with the MCS?
No—only Agilent GC models with LAN/Ethernet connectivity and supported firmware versions (7890B Rev. G.04.02 or later, 8890 Rev. B.08.03 or later) are compatible with MCS hardware and MAESTRO control.