News from LabRulezLCMS Library - Week 21, 2025

Our Library never stops expanding. What are the most recent contributions to LabRulezLCMS Library in the week of 19th May 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 presentation by Agilent Technologies, application notes by Metrohm, Shimadzu and other document by Thermo Fisher Scientific!

1. Agilent Technologies: Getting the Most From Your Agilent HPLC Pump 

• Presentation
• Full PDF for download

The “Getting the Most From Your Agilent HPLC Pump” guide, authored by Mark Powell and presented in January 2025, provides a thorough overview of best practices for using, maintaining, and troubleshooting Agilent HPLC pumps. It begins with a comparison of high-pressure versus low-pressure mixing systems and their impact on dwell volume, retention time, and peak resolution. The document explains how various pump configurations—including quaternary, binary, and high-speed designs—relate to analytical performance and how system components like restriction capillaries and column types affect pressure and dispersion.

A significant portion of the guide focuses on routine maintenance and mobile phase hygiene. Emphasis is placed on correct handling of solvents (e.g., acetonitrile), filtration, degasser care, and the importance of daily and weekly cleaning tasks to prevent cavitation, ghost peaks, or pressure spikes. The use of InfinityLab Stay Safe Caps, regular replacement of solvent inlet filters, and the implementation of a seal wash protocol (with 90:10 water/isopropanol) are highlighted as key steps to prolong pump and seal life, especially when working with buffers or volatile solvents.

The document also clarifies the distinctions between purging, conditioning, and priming the system—each serving different roles depending on the operational context. It warns against using the Prime function to fill empty solvent lines due to potential seal damage. Additionally, system tuning and pressure ripple monitoring are addressed, with recommendations on how to recognize and respond to performance issues such as air bubbles, valve blockages, or incorrect compressibility settings.

Finally, the guide provides detailed shutdown procedures, part numbers for maintenance kits and filters, and guidance for working in specialized modes like normal phase or gel permeation chromatography (GPC). With supplementary support from videos, Agilent’s Lab Advisor software, and InfinityLab Assist, users are well-equipped to ensure reliable pump performance and reduce downtime. Notably, no Shimadzu instruments are referenced in this guide—it is dedicated solely to Agilent HPLC systems.

2. Metrohm: Sodium content in water using an ion-selective electrode 

Fast, accurate, and selective determination in mineral water and leachate according to AOAC 976.25

• Application note
• Full PDF for download

Groundwater naturally occurs by means of precipitation, and it gathers dissolved minerals as it filters and passes through the soil. Typically, groundwater is used as a source for drinking water and irrigation purposes. Rain and snow can also leach various substances, such as sodium salts, from landfills into groundwater. This so-called leachate is considered hazardous to the environment and can contaminate groundwater reserves. This Application Note describes sodium analysis in water (mineral water as well as leachate) using the separate sodium-selective electrode, also known as the Na-ISE. All samples in this study were determined by standard addition. The method is based on the standard AOAC 976.25.

The standard addition (STDADD) is recommended for undefined or complex sample matrices. In the standard addition method, a defined amount of the ion of interest is added to a known volume of sample (in several steps). The unknown concentration can be calculated from the resulting potential differences between the sample and the sample with added standard solution. This calculation is performed automatically by modern ion meters or software such as OMNIS. 

EXPERIMENTAL 

An OMNIS Advanced Titrator and an OMNIS Dosing Module equipped with a separate sodium-selective electrode were used to measure sodium in water samples (Figure 1).

CONCLUSION 

Results of sodium measurement in water with the sodium ion-selective electrode are fast, reproducible, and accurate. In principle, this method can be used for any type of wastewater or sewage water for different sodium concentrations. Appropriate dilution or clarification (e.g., filtration or centrifugation) may be required prior to analysis. Handling the Na-ISE is user friendly and there is no need to condition the electrode, which means it is immediately ready for use. Furthermore, this method conforms to AOAC 976.25. The analytical system presented in this application offers users flexibility combined with high-end software. The measuring range of the separate polymer Na-ISE lies between 5 × 10–6 mol/L and 1 mol/L Na+ (corresponds to approximately 0.11 mg/L Na+ ) and is suitable for a wide range of different samples, from foodstuffs to pharmaceutical products and cosmetics. As well as improving the precision and speed of sodium determinations, OMNIS delivers results that are equal to or better than other established titration systems.

3. Shimadzu: Qualitative Analysis of Drugs in Blood Using LCMS-9030 and MS/MS Spectral Libraries 

• Application note
• Full PDF for download

User Benefits

• Qualitative screening of drugs using LCMS-9030 can be performed in 15 minutes.
• LabSolutions Insight Discovery and High ResolutionAccurate Mass Library for Forensic Toxicology Ver. 2 simplify the analysis of
  measurement data .

Many forensic toxicological analyses are related to overdoses of prescription or over-the-counter drugs, and the majority of drugs consumed are psychiatric drugs such as sleeping drugs, antidepressants, and anti-anxiety drugs. Hikiji et al. 1) reported 30 drugs that are at high risk of causing death due to overdose. In addition, Asano et al. 2) reported the top 20 psychotropic drugs left in the places where bodies were discovered, and according to that, sleeping drugs, anti-anxiety drugs, antidepressants, and antipsychotic drugs were particularly common. Many of the drugs listed in both reports are the same and are considered important targets for forensic toxicological analysis. For this reason, forensic toxicological analysis requires a workflow that can reliably identify the important related componentswithout any omissions. 

This application introduces an example of drug qualitative screening using the LCMS -9030 quadrupole time-of-flight (QTOF) mass spectrometer, LabSolutions Insight Discovery, and “High Resolution Accurate Mass Library for Forensic Toxicology Ver. 2” (Fig. 1).

Qualitative Screening Using LCMS-9030

The library similarity and mass errors of 25 drugs added to bovine whole blood are shown in Table 3, the measured spectra of some drugs in Fig. 3, and the MS chromatogram of the acquired data in Fig. 4. Although there were many matrixderived peaks in the sample and some drugs had retention times that were very close to each other, all the spiked drugs were identified, and their library similarity was 82-99. The difference between the measured and theoretical precursor ion m/z valuesfor each drug was within 1 ppm.

Conclusion

Qualitative screening with LCMS-9030 was performed on bovine whole blood spiked with 25 drugs. All the spiked drugs were identified with a library similarity of more than 80 and high mass accuracy from a sample containing many matrix-derived components. These results demonstrate the usefulness of the LCMS-9030 and the “High Resolution Accurate Mass Library for Forensic ToxicologyVer. 2” in the qualitative screeningof drugs.

4. Thermo Fisher Scientific: Plasma proteomics: harnessing cutting-edge technologies for unprecedented depth and throughput 

• Other document (Case study)
• Full PDF for download

Unlocking secrets of the proteome 

Mass spectrometry is considered a gold standard technique in proteomics and the most comprehensive approach to truly understanding the proteome. Mass spectrometry, often coupled with liquid chromatography (LC-MS), offers the invaluable benefits of unrivaled sensitivity and specificity for protein identification while also maintaining the versatility needed for detailed information on protein composition and structure. As a result, mass spectrometry–based proteomics can be seen as the universal key uniquely capable of unlocking secrets of recent advancements. the proteome.

While advancements in genomics and transcriptomics have deepened our understanding of biology and ushered in new applications and diagnostic solutions that impact everyday human life, it is widely understood that proteins provide real-time insights for understanding disease onset, progression, and treatment. For example, the potential of the blood plasma proteome as an indicator of disease and health status ushers in new ways in which LC-MS–based proteomics can be utilized to improve overall human health outcomes. However, all of this does not come without challenges; the large dynamic range and diversity of protein variants in plasma make it very difficult to achieve the simultaneous depth of coverage and throughput required for large-scale plasma proteome studies, and as a result, much of the human proteome has been inaccessible until recent advancements.