The following strategies are recommended: optimize chromatographic conditions by adjusting the gradient elution program, flow rate, column temperature, etc.
Utilize high-resolution mass spectrometry modes: For instance, select the wide mass range mode of MS²Vertical9020 to enhance spectral resolution.
Combined with pretreatment techniques such as solid-phase extraction and derivatization, the enrichment degree and response of the target substance can be improved.
The multi-response monitoring mode was adopted to improve the selectivity and signal-to-noise ratio of the target compound.
Possible causes include: Ion source contamination: Regular cleaning of components such as ESI or APCI spray nozzles and cone holes is required.
Decline in column performance: Replacement or regeneration of the chromatographic column is recommended.
Abnormal mass spectrometry tuning: Re-calibration of mass and sensitivity adjustment are required.
Impurities in the mobile phase or gas: Use reagents and gases of high purity.
The positive ion mode is suitable for basic or proton-donating compounds (e.g., amines, alkaloids), while the negative ion mode is applicable to acidic or proton-accepting compounds (e.g., carboxylic acids, phenols). For samples with complex or unknown compositions, it is recommended to perform simultaneous positive and negative mode scans, or select models that support rapid positive-negative mode switching (e.g., MS² Vertical 9100).
Because different classes of compounds respond differently to various detectors. Selecting the appropriate detector is akin to choosing sensitive 'eyes' for different 'targets'.
The vast majority of samples require pretreatment and cannot be directly injected. This is a critical step to ensure the accuracy and reliability of analytical results. Common pretreatment methods include: Purification: Removal of impurities that interfere with the analysis of the target substance.
Extraction/Concentration: The target substance is separated and enriched from complex matrices (e.g., water, soil, biological tissues) to achieve the detection limit of the instrument.
Derivatization: For certain compounds that are difficult to volatilize or exhibit weak detection signals, they are chemically converted into forms suitable for GC analysis.
Although the pretreatment increases the steps, it can greatly improve the sensitivity and accuracy of the analysis.
The key difference between the two lies in the nature of the sample being analyzed.
Gas chromatograph (GC): Suitable for samples that can be vaporized and exhibit good thermal stability. Primarily used for detecting volatile and semi-volatile organic compounds, such as gases, gasoline, fragrances, and solvent residues.
High Performance Liquid Chromatograph (HPLC): Suitable for samples with high boiling points, low volatility, thermal instability, and biological activity. Primarily used for the detection of macromolecules and ionic compounds, such as proteins, nucleic acids, most pharmaceuticals, and amino acids.
In short, the basic selection principle is: samples that can be vaporized for GC analysis should be used for GC, while those that cannot be vaporized for HPLC should be used for HPLC.
We have designed a highly integrated solvent switching system and an intelligent Kromstation chromatography workstation, which are developed and operated through graphical interface guidance, significantly reducing operational complexity. The instrument features automatic dilution and automatic derivatization, simplifying the pretreatment steps. Nevertheless, we strongly recommend that users participate in the standard operating and maintenance training provided by us to fully utilize the instrument's performance and ensure the reliability of analytical results. We also offer multi-level remote support and on-site technical services.
The price of the instrument varies depending on the configuration, such as the type of detector, the number of temperature control modules, and whether special functional modules (e.g., preparation, online pre-treatment) are integrated, all of which affect the final price. Generally, the price of a two-dimensional system is higher than that of a conventional liquid chromatography system. For a specific quote, please contact our sales team to obtain a customized solution and detailed quotation tailored to your needs.