Waters ACQUITY Arc System

Overview

The Waters ACQUITY Arc System is a purpose-engineered liquid chromatography platform designed to bridge the operational and methodological gap between conventional high-performance liquid chromatography (HPLC) and ultra-high performance liquid chromatography (UHPLC). Built upon Waters’ proprietary Arc Multi-Flow Path architecture, the system delivers method-agnostic operation—enabling seamless transition between legacy HPLC methods (using 3.0–5.0 µm particles) and modern UHPLC separations (optimized for 2.0–2.7 µm particles) without hardware reconfiguration or gradient table recalibration. Unlike fixed-volume systems, the ACQUITY Arc dynamically selects the appropriate flow path to match column dimensions and particle size, minimizing system dwell volume mismatch and preserving retention time reproducibility across platforms. This architecture ensures compliance with pharmacopeial method transfer requirements while maintaining full compatibility with existing validated workflows under GxP-regulated environments.

Key Features

• Arc Multi-Flow Path Technology: Dual-path solvent delivery system automatically adjusts system dispersion characteristics—Path 1 optimized for traditional HPLC columns (e.g., 4.6 × 150 mm, 5 µm), Path 2 engineered for UHPLC columns (e.g., 2.1 × 50 mm, 2.2 µm)—eliminating manual dwell volume compensation.
• Quaternary Solvent Manager with Expandable Solvent Selection: Standard four-solvent mixing capability; optionally configurable up to nine solvents via integrated solvent selection valve for complex gradient methods and pH/ion strength modulation.
• Auto Blend Plus Technology: Enables real-time, on-the-fly adjustment of mobile phase pH and ionic strength by dynamically blending pure solvents and buffer concentrates—reducing manual preparation error and enhancing inter-day reproducibility.
• Low-Cross-Contamination Autosampler: Equipped with Flow-Through Needle (FTN) mode, continuously rinsing the needle interior during injection cycles to achieve carryover < 0.002%, critical for trace-level quantitation and regulated bioanalysis.
• Integrated Column Thermal Management: Optional column oven with active heating/cooling and pre-heater module ensures consistent temperature control across all system zones—essential for inter-laboratory method transfer and long-term retention time stability.
• Regulatory-Ready Architecture: Designed to support audit trails, electronic signatures, and role-based access control when operated with Empower 3 software—fully aligned with FDA 21 CFR Part 11, EU Annex 11, and ISO/IEC 17025 requirements.

Sample Compatibility & Compliance

The ACQUITY Arc accommodates a broad range of sample matrices—including small molecules, peptides, oligonucleotides, and polar metabolites—across reversed-phase, HILIC, ion-pair, and mixed-mode separations. Its pressure rating (up to 15,000 psi) and low system volume (< 100 µL total dwell volume in UHPLC mode) ensure robust performance with sub-2-µm columns while maintaining compatibility with legacy 5-µm HPLC methods. The system meets key regulatory benchmarks: it supports IQ/OQ/PQ documentation packages, integrates with Waters’ System Qualification Tools (SQT) for automated qualification per USP , and enables full lifecycle traceability required for GLP and GMP environments. All firmware and software updates are version-controlled and validated per Waters’ quality management system.

Software & Data Management

Instrument operation and data handling are unified through two complementary software environments: Empower 3 for chromatographic acquisition, processing, and compliance reporting; and MassLynx for mass spectrometric data acquisition when coupled with the ACQUITY QDa detector. Empower 3 provides automated system startup sequences—including prime, purge, and equilibration routines—as well as real-time monitoring via Instrument Console, which displays live status of pumps, autosampler, column oven, and detector on a single dashboard. Audit trail functionality captures all user actions, parameter changes, and data modifications with timestamped, immutable records. Raw data files adhere to Waters’ open-format .raw structure, ensuring long-term archival integrity and third-party software interoperability.

Applications

The ACQUITY Arc serves as a transitional and production-grade LC platform across pharmaceutical development, quality control, clinical research, and academic laboratories. It is routinely deployed for: forced degradation studies requiring method robustness across column chemistries; stability-indicating assays where retention time alignment between HPLC and UHPLC is mandated; QC release testing of drug substances and products under compendial monographs; and method scouting for new chemical entities where rapid column and mobile phase screening is essential. Its compatibility with ACQUITY QDa enables routine LC-MS confirmation without workflow disruption—supporting peak identity verification, unknown impurity tracking, and molecular weight assignment directly from gradient runs.

FAQ

Can the ACQUITY Arc run both HPLC and UHPLC methods on the same instrument without hardware modification?
Yes. The Arc Multi-Flow Path architecture allows users to switch between HPLC- and UHPLC-optimized flow paths via software command—no physical valve changes or tubing swaps are required.
Is method transfer from legacy HPLC systems to the ACQUITY Arc supported without gradient reprogramming?
Yes. The system auto-compensates for dwell volume differences using intelligent gradient start logic—retention times and peak shapes are preserved without altering original gradient tables.
Does the ACQUITY Arc meet FDA 21 CFR Part 11 requirements?
Yes. When configured with Empower 3 and appropriate IT infrastructure, the system supports electronic signatures, audit trails, and secure user authentication per Part 11 Annex A guidelines.
What column particle sizes does the ACQUITY Arc support?
It is validated for columns packed with 2.0–5.0 µm particles—including 2.2 µm BEH C18, 3.5 µm XBridge, and 5 µm Symmetry columns—without compromising resolution or backpressure limits.
Is the ACQUITY QDa detector fully integrated into the ACQUITY Arc workflow?
Yes. QDa detection is controlled natively within Empower 3; mass spectral data is acquired synchronously with UV signals, enabling co-registered peak identification and library matching without external data reconciliation.