Piecewise direct standardization assisted with second-order calibration methods to solve signal instability in...

Area of Science:

• Analytical Chemistry
• Chemometrics
• Chromatography

Background:

• Signal instability in high-performance liquid chromatography-diode array detection (HPLC-DAD) data can compromise quantitative accuracy.
• Maintaining the advantages of second-order calibration methods is crucial for complex mixture analysis.
• Time shifts and peak shape changes are common challenges in chromatographic data.

Purpose of the Study:

• To propose and evaluate a novel method for analyzing unstable HPLC-DAD data.
• To maintain the benefits of second-order calibration in the presence of signal instability.
• To improve the accuracy and efficiency of quantitative analysis for complex samples.

Main Methods:

• Piecewise direct standardization (PDS) combined with second-order calibration techniques.
• Alternating trilinear decomposition (ATLD) algorithm.
• Alternating trilinear decomposition assisted multivariate curve resolution (ATLD-MCR) algorithm.
• Comparison with MCR-ALS algorithm.

Main Results:

• Accurate quantitative results were achieved for simulated and real HPLC-DAD data with signal instability.
• PDS combined with ATLD and ATLD-MCR demonstrated superior performance compared to models without PDS.
• The proposed methods effectively handled time shifts and peak shape variations.
• Statistical analysis (t-test) confirmed significant improvements in quantitative results.

Conclusions:

• PDS assisted with second-order calibration methods offers a robust solution for unstable HPLC-DAD data.
• The methodology reduces the need for recalibration, enhancing experimental efficiency and aligning with green chemistry principles.
• This approach shows significant potential for analyzing complex samples with signal instability, including pesticide residue analysis.