News from LabRulezLCMS Library - Week 43, 2025

Our Library never stops expanding. What are the most recent contributions to LabRulezLCMS Library in the week of 20th October 2025? Check out new documents from the field of liquid phase, especially HPLC and LC/MS techniques!

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This week we bring you posters by Agilent Technologies / AOAC, Shimadzu / AOAC and Thermo Fisher Scientific / HPLC Symposium and application note by Waters Corporation!

1. Agilent Technologies / AOAC: Evaluating System Robustness of a High-Sensitivity Triple Quadrupole LC/MS for PFAS Analysis in Food Matrix Over an Extended Period 

• Poster
• Full PDF for download

Due to the rapidly evolving regulatory environment of per- and polyfluoroalkyl substances (PFAS), many analytical laboratories are opting to use highsensitivity triple quadrupole mass spectrometers for the targeted analysis of such compounds to ensure meeting present and potential future requirements for sensitivity and PFAS coverage. These assays are regularly conducted in a high-throughput manner involving complex matrices such as food, soil, wastewater or biological samples. Therefore, system robustness and instrument uptime are crucial for such applications to maintain productivity and profitability. In this work, we present results from an expedited robustness testing of a high-sensitivity triple quadrupole LC/MS system using select PFASs in one of the most challenging food matrices.

Experimental

Instrumentation

Data was collected using an Agilent 1290 Infinity II LC system coupled to an Agilent 6495D LC/TQ mass spectrometer. Instrument parameters are summarized in Tables 1 and 2.

Conclusions

The robustness of a 6495D LC/TQ was tested using undiluted salmon extract, a complex and challenging food matrix. During the experiment, the system was exposed to more than 130 mL of the matrix over a period of ~3 weeks of continuous operation, without any maintenance. System performance was monitored by injections of a mixture of native and isotopically labelled PFAS samples. The monitored signals exhibited low variations (RSD<6%) throughout the entire experiment. No obvious performance degradation or significant contamination of the inner ion optics elements were observed after the conclusion of the test. 

Although no loss of instrument performance was observed during this expedited robustness test, a routine maintenance of ion source and optics is recommended to ensure prolonged instrument operation.

2. Shimadzu / AOAC: Analysis of Chlordane by DUIS (Dual Electrospray/Atmospheric Pressure Chemical Ionization) Liquid Chromatography Mass Spectrometry 

• Poster
• Full PDF for download

The legalization of cannabis has led to many laboratories developing methods to meet local cannabis testing regulatory requirements. One of the challenging residual pesticides to quantitate is chlordane, an organochlorine compound used as a pesticide on crops until 1983 and for termite treatment in homes until 1988. Chlordane is highly persistent in the environment and has been linked to cancers. Gas chromatography mass spectrometry and atmospheric pressure chemical ionization (APCI) – liquid chromatography mass spectrometry (LCMS) methods were published for analysis of chlordane. However, for laboratories without APCI functionality or who prefer not to switch between two different ionization sources, chlordane remains a challenging target for LCMS analysis. This study demonstrates the successful quantitation of chlordane using additive-free DUIS electrospray ionization – LCMS at concentrations below the New York State testing limits.

Methods 

Technical chlordane (CAS 57-74-9) was obtained from Restek, diluted in water, and analyzed on a Shimadzu LCMS-8060 triple quadrupole mass spectrometer equipped with a DUIS ionization source. The DUIS source was utilized in APCI mode. Technical chlordane is a mixture of transchlordane, cis-chlordane, and related chemicals. The LC parameters shown in Table 1 allowed separation of the cis- and trans-chlordane isomers.

Results 

Initial MS data was collected in Q1 and Q3 Scan mode. Due to the 8 chlorine atoms per chlordane molecule, a distribution of isomers is expected in the mass spectrum. LabSolutions Insight Explore was used to predict isotopic distributions for chlordane with and without adducts. The predicted spectra for the [M-H]- and [M+CH3OH]- are shown in Figure 1A and 1B, respectively. The experimentally observed isotopic distributions for the [M-H]- and [M+CH3OH]- ions are shown in Figure 1C and 1D, respectively. Figure 1E shows the relative intensity of the [M+CH3OH]- versus the [M-H]- isotope clusters. As the [M+CH3OH]- showed the greatest intensity, it was selected for optimization.

Voltage optimization was performed for the 441.80 to 441.80 MRM with the CID gas turned off. Even after voltage optimization, the signal-to-noise from the primary species in the technical chlordane (in this case, trans-chlordane) was insufficient. Automated source optimization using LabSolutions MRM Connect was used to improve signal by optimizing Interface Temperature, Heating Gas Flow, Nebulizing Gas Flow, Drying Gas Flow, DL Temperature, Heat Block Temperature, and Interface Voltage. As a representative example, Figure 3 shows the impact of Interface Temperature on the MRM intensity for the 441.80 m/z.

3. Thermo Fisher Scientific / HPLC Symposium: HPLC transfer and optimization of deoxycholic acid analysis using HPLC – Charged Aerosol Detector

• Poster
• Full PDF for download

The United States Pharmacopeial Convention monograph outlines a high-performance liquid chromatography with charged aerosol detection (HPLC-CAD) method [1] for the accurate measurement of deoxycholic acid (also known as desoxycholic acid) and its primary impurity, cholic acid. Key detector settings that influence detection performance metrics such as detection limit, resolution, and linearity include: 

• The evaporation temperature (EvapT) for setting the temperature of the evaporation tube and influencing sensitivity related to volatility factors. 
• The filter constant for balancing noise and adjusting the detector's response time to changes in analyte concentration. 
• The PV for optimizing the linear range within the detector's dynamic range for a given application. 

These parameters are crucial for successful method transfer and optimization. Consequently, this work offers guidelines for method transfer and optimization from the Vanquish CAD to the Vanquish CAD HP

Methods: A Thermo Scientific Vanquish Flex UHPLC system equipped with both the Vanquish Charged Aerosol Detector and HP was used to perform method transfer and optimization for deoxycholic acid analysis. Chromatographic separation was achieved using a Thermo Scientific Acclaim 120 C18 column under gradient elution with formic acid-modified aqueous and organic phases

Chromatography Data System 

The Thermo Scientific Chromeleon 7.3.2 Chromatography Data System (CDS) software was used for data acquisition and analysis.

Conclusions 

This study highlights the successful optimization and method transfer of the USP-NF deoxycholic acid assay using Vanquish CAD detectors. Through careful evaluation of chromatographic performance, detector settings, and calibration parameters, the Vanquish CAD HP was shown to deliver enhanced performance across multiple criteria: 

Key Takeaways: 

• Excellent Sensitivity and Response: Vanquish CAD HP demonstrated significantly lower LOD/LOQ values and higher peak responses compared to Vanquish CAD, making it the detector of choice for low-level analyte quantification. 
• Enhanced method optimization Flexibility: Vanquish CAD HP allows simultaneous data collection for multiple PVs, ensuring faster method development and optimization. 
• Seamless Method Transfer: Transitioning from Vanquish CAD to CAD HP was achieved by optimizing power value (PV), EvapT, and signal filter settings, ensuring improved performance. 

Together, these findings demonstrate that the Vanquish CAD HP not only supports efficient method transfer but also elevates performance, sensitivity, and usability—making it an ideal solution for modern HPLC applications.

4. Waters Corporation: Multi-Residue Analysis of Pharmaceuticals, Personal Care Products (PPCPs) and Pesticides in Water by Direct Injection Using LC-MS/MS

• Application note
• Full PDF for download

Benefits 

• Sensitivity of Xevo TQ Absolute allows for the trace level detection of PPCPs and pesticides in drinking and surface waters without the need for lengthy clean-up or concentration steps
• The direct injection approach increases productivity and provides faster turn-around time for reporting of results while being well aligned with green analytical chemistry principles
• More than 150 analytes reach limits of quantification of 10 ng/L, making this method suitable for screening for multi-class analytes in water matrices 

In recent years, there has been increasing concern about the presence of pesticides, pharmaceuticals and personal care products (PPCPs) in water bodies throughout the world.1 The effect of these emerging contaminants on human health and their potential impact on the environment is not yet fully understood. The updated Drinking Water Directive entered into force in January 2021 and is the EU's main law for drinking water. The Directive applies to all water, either in its original state or after treatment, intended for drinking, cooking, food preparation or other domestic purposes, regardless of its origin and whether it is supplied from a distribution network, supplied from a tanker or put into bottles or containers.2 It further protects human health thanks to updated water quality standards, in accordance with World Health Organisation (WHO) recommendations, addressing emerging pollutants, such as endocrine disruptors, and promoting a preventive, risk-based approach to reduce pollution at its source.

Water bodies such as rivers, lakes and groundwaters have their status defined in the EU Water Framework Directive.3 An amendment to Directive 2013/39/EU sets environmental quality standards for hazardous substances that require monitoring in these waters. A Commission Implementing Decision4 document, 2022/1307, includes Watch List analytes with Maximum Acceptable Method Detection Limits for compounds of concern across multiple chemical classes. Numerous studies have demonstrated that PPCPs are present at parts-per-trillion (PPT) levels in rivers and streams highlighting the need for methods that are able to detect compounds at these trace levels.5-10 In addition to the low-level detection of these compounds, a major analytical challenge lies in the wide chemical diversity of chemicals of concern. Furthermore, to establish a more complete understanding of water pollution it is necessary to monitor a wide variety of types of water. This application note demonstrates the direct injection, separation and detection of PPCPs and pesticides including acidic, basic, and neutral compounds from multiple regulated analyte lists in a variety of water types.

Experimental

• LC system: ACQUITY Premier FTN
• MS system: Xevo TQ Absolute

Conclusion 

The updated EU Drinking Water and Water Framework Directives provide the regulatory framework for effective monitoring and management of water quality and include provisions for emerging contaminants. Ensuring compliance with these regulations and comprehensive coverage for an ever increasing analyte lists requires versatile, robust analytical methods and high performance LC/MS/MS systems. The direct-injection method investigated in this work is effective at detection of a wide range of PPCPs and pesticides at trace levels suitable for monitoring multiple water types for the presence of compound classes known or suspected to pose risks to human and environmental health. It further provides more rapid turn around time and greener operation than methods that rely upon high volumes of solvent and extensive sample preparation. Method performance was assessed using criteria described in ISO 21253–2:2019. The calibration characteristics, linearity, and residuals were excellent over the concentration range studied. Accuracy and precision were evaluated at three matrix QC levels with six replicate spikes and found to provide excellent performance for 154 analytes in tap and bottled water and 74 analytes in surface water matrix.