Invion – the next generation ion source

For rapid switching between ultra-pure reagent ions

The Invion source by IONICON enables rapid, high-purity reagent ion switching for advanced PTR-MS applications, offering enhanced analytical precision and operational safety.

The ability to switch between reagent ions almost instantly – including H₃O⁺, NH₄⁺, NO⁺, and O₂⁺ – enables superior compound discrimination, even in highly dynamic measurement environments (Fig. 1).

Fig. 1: Demonstration of the Invion’s capability to quickly and reproducibly switch between ionization modes (O₂⁺, H₃O⁺, NH₄⁺) and E/N for H₃O⁺, supporting time-resolved multi-mode analysis.

Outstanding purity

It is important to note that in all SRI modes, the reagent ion purity remains above 98%, consistent with the high performance achieved by IONICON PTR-MS systems. An overview of the typical impurities of reagent ions in percent is shown in Table 1.

Tab. 1: Overview of the impurity levels of the primary reagent ions in percent in different SRI modes.

Despite the considerably reduced SRI switching time (1 s), the purities of the individual reagent ions was further improved to well above 98%. NH₄⁺ is produced without the need for any hazardous ammonia, utilizing IONICON’s patented method (US11342171 (B2), CN111386590 (B), EP3503161 (B1)).
Plasma-based ion sources are known to produce reactive radicals (e.g., OH from water plasma), which can cause intrinsic oxidation of analytes, leading to erroneous measurement artifacts. The Invion source mitigates this issue by preventing radicals from entering the reaction chamber, thus maintaining the integrity of the sample.
To test for potential artifacts, 10 ppbv of limonene was analyzed using H₃O⁺ reagent ions. Limonene readily reacts with OH radicals, forming products such as 4-acetyl-1-methyl-cyclohexene (m/z 139.112) and limononaldehyde (m/z 169.122). The results show that these oxidized by-products accounted for less than 0.4% of the total limonene signal – proof that the Invion source is virtually free of radicals (Fig. 2).

Fig. 2: The results show that oxidized by-products account for less than 0.4% of the total limonene signal, highlighting that the Invion source is virtually free of radicals.

Trusted durability and low maintenance

In addition to its analytical capacilities, the Invion source is engineered for long operational life, exceptional stability, and minimal maintenance. These qualities make it an ideal solution for demanding, high-throughput environments where reliability and uptime are critical.

Efficient operation with minimal resources

Invion is highly economical in terms of resource consumption. To fully utilize the range of positive reagent ions, only trace amounts of water, nitrogen (N₂) and oxygen (O₂) are required. This means that no costly consumables or toxic chemicals are required and therefore no hazardous waste is produced, which benefits both cost efficiency and environmental friendliness.

FUSION & Invion – positive and negative reagent ions

The Invion source offers a powerful ionization mode that optimizes selectivity in the detection of inorganic and organic acids. This technology is used in the FUSION PTR-TOF series from IONICON. In particular, CO₃⁻ ionization provides enhanced selectivity for acids and volatile inorganic compounds, including SO₂, HNO₃, H₂SO₄, and halogenated compounds such as perfluoroalkyl carboxylic acids (PFCAs).

Learn more about the possibilities with FUSION PTR-TOF.