Сдвоенная система ионизации DUIS-2020
Наряду с традиционными системами ионизации (ESI и APCI) жидкостный хроматомасс-спектрометр LCMS-2020 может комплектоваться универсальным двойным источником ионизации (DUIS), который может одновременно ионизировать пробу в режиме электроспрея и при помощи химической ионизации. Таким образом, в ходе одного измерения можно проанализировать вещества различной природы, что еще больше увеличивает функциональность и производительность аналитической системы.
This increases laboratory efficiency by making it possible to analyze a wide range of chemical species. DUIS ionization is particularly useful in the confirmation of synthetic compounds, or for confirming reaction byproducts and other unknown substances. Pharmaceutical drug discovery groups or any laboratory analyzing both polar and non-polar analytes will benefit from the Dual Ion Source.
(LCMSsolution, версия 5 или выше)
Operating Principle and Structure of the Dual Ion Source
The Dual ion source simultaneously ionizes samples using two ionization methods - electrospray ionization (ESI), which is suitable for high polarity compounds, and atmospheric pressure chemical ionization (APCI), which is suitable for low-to-medium polarity compounds. Therefore, it is capable of ionizing a wide range of compounds, including chemical classes from low to high polarity.
Samples sent to the dual ion source are ionized by an electrospray ionization (ESI) probe, and simultaneously ionized by an atmospheric pressure chemical ionization (APCI) corona discharge needle located below the ESI outlet. This is useful when it is desirable to analyze compounds suited to both ESI and APCI in the same analytical run. Because both the ESI and APCI voltages operate continuously, no switching time is required, and the DUIS performs analysis with high reliability and reproducibility without loss of data, even for analyses with narrow peaks obtained using ultra fast liquid chromatography.
The DUIS-2020 dual ion source option has a simple structure and is easy to maintain. The DUIS-2020 voltages can be independently controlled and its data processed using LCMSsolution software for LCMS-2020 systems.
Enables ESI, APCI, Positive, and Negative Ionization in the Same Analysis
Significantly Improves Efficiency by Simultaneously Analyzing a Wide Variety of Compounds in a Single Run
The following is an example of analysis using the dual ion source. Good response can be obtained for riboflavin by detecting the protonated molecule using ESI, though APCI response is minimal. A good response can also be obtained by ESI for thiamin, but it cannot be detected using APCI. In contrast, for calciferol, the protonated molecule can be detected using APCI, but ionization by ESI is inadequate. All three species are detected with good sensitivity when the DUIS-2020 is employed. In addition to clear advantages in ionization capabilities, the DUIS-2020 yields high quality spectra as shown below.
MS Chromatograms Obtained Using the DUIS-2020
Spectra Obtained Using the DUIS-2020
This ion source is ideal for confirming the molecular weights of synthetic compounds or for simultaneously analyzing a wide range of compounds with polarity ranging from low to high. It also offers higher sensitivity (based on a 2006 study) than other commercially available systems in its class. For some samples, however, sensitivity is lower than using the standard ESI or APCI ion source on the LCMS-2020. Therefore, for the highest sensitivity analysis, the standard ion source may be the best choice.