Specifications PAL RTC / RSI including Series II (LC & GC)

Importance of the Topic

The precision and reliability of liquid handling and injection directly impact data quality in chromatographic analyses. Automated platforms such as the PAL RTC/RSI series enable consistent sample introduction in high-performance liquid chromatography (HPLC) and gas chromatography (GC), reducing human error and improving reproducibility in research, quality control, and industrial applications.

Objectives and Overview

This document summarizes gravimetric and analytical performance specifications for the PAL RTC/RSI including Series II modules, covering syringe-based liquid handling, HPLC and GC injection repeatability, linearity and carry-over, as well as performance of dilutor and pipette tools. It provides a consolidated view of key metrics to guide method development and system validation.

Methodology and Instrumentation

Performance was assessed by gravimetric measurement and chromatographic tests under controlled conditions:

• Gravimetric precision and linearity of 10 µL and 100 µL syringes using a Mettler Toledo New Classic MF balance (d=0.01 mg).
• HPLC injection repeatability and linearity with standard syringes and LCMS-P tool on an Agilent 1290 Infinity system using C8 and C18 columns.
• Carry-over studies in HPLC with chlorhexidine and acetonaphthone, employing fast wash and valve toggle routines.
• GC liquid injection and headspace injection tests using Agilent FID and split/splitless inlets, evaluating alkanes and iso-octane.
• Gravimetric evaluation of the dilutor module in delivery and transfer modes across 10–10 000 µL ranges.
• Pipette tool single and multi-dispense tests (200 µL and 1000 µL) using Precisa XB balance (d=0.1 mg) and defined liquid classes for water.

Main Results and Discussion

Key performance highlights include:

• Syringes: Repeatability RSD ≤1 % (10 µL) and ≤0.1 % (100 µL); linearity R² ≥0.999 over full range.
• HPLC injections (standard): Full-loop repeatability RSD ≤0.1 %, partial-loop ≤0.15 %; linearity R² ≥0.999; carry-over ≤0.02 %.
• HPLC injections (LCMS-P): Partial-loop repeatability RSD ≤0.5 %; carry-over ≤0.004 % with cycle times ≤1 min.
• Small-volume HPLC: Three injections of 1.5 µL from a 5 µL sample confirmed minimal dead volume.
• GC liquid injection: Alkane RSD ≤0.6 %; carry-over ≤40 ppm in first blank.
• GC headspace: Repeatability RSD ≤1 %; carry-over ≤1000 ppm (blank 1) and ≤500 ppm (blank 2); needle discrimination C40/C20 ≥0.98.
• Dilutor tool: Delivery mode repeatability RSD ≤0.1–0.5 % (50–10 000 µL); linearity R² ≥0.999; transfer mode RSD ≤0.5–1.5 %.
• Pipette tool: Single-dispense RSD ≤0.5 % (100–1000 µL) and ≤1.5 % (20 µL), accuracy within 0.5–2 %; multi-dispense RSD ≤1–2 %.
• Pipette-based HPLC injections: RSD ≤0.3 % and carry-over ≤0.004 % for acetonaphthone.

Benefits and Practical Applications

These robust performance characteristics enable high-throughput sample processing with consistent accuracy and minimal carry-over. Laboratories benefit from reduced manual intervention, streamlined workflows for QC/QA, and reliable method transfer across analytical platforms.

Future Trends and Applications

Future developments may include tighter integration with mass spectrometry interfaces, further miniaturization for nanoliter-scale injections, advanced wash protocols for ultra-low carry-over, and cloud-enabled diagnostics for predictive maintenance and data integrity assurance.

Conclusion

The PAL RTC/RSI series including Series II demonstrates excellent precision, linearity, and low carry-over across a wide range of volumes and injection techniques. Its modular design and validated performance support a broad spectrum of chromatographic applications, ensuring reproducible results and operational efficiency.

Used Instrumentation

• PAL RTC/RSI including Series II (LC & GC) modules
• Mettler Toledo New Classic MF balance (d=0.01 mg)
• Precisa XB 120A balance (d=0.1 mg)
• Agilent 1290 Infinity HPLC system with Phenomenex Kinetex and HALO C18/C8 columns
• Agilent FID GC with split/splitless inlets and ZB-5 column
• PAL headspace injection module and dilutor tools with LCMS-P valve assemblies