The Thermo Scientific™ NEPTUNE Plus is a double-focusing multicollector ICPMS, based upon field-proven technologies from the NEPTUNE: high mass resolution, variable multicollectors, and multi ion counting. New features of the Neptune Plus include the Jet Interface for ground-breaking sensitivity, a dual RPQ option and multiple discrete dynode electron multipliers for high-dynamic ranges, unsurpassed linearity, and stability.
The ion optics of the NEPTUNE Plus MC-ICPMS provide high mass resolving power on all detectors along the image plane. The instrument can be operated at three different resolution settings: low, medium and high resolution can be selected with a mouse-click. In high resolution, resolving powers of up to m/∆m = 8,000 at >10% transmission can be achieved. The m/∆m is derived from the peak slope of the rising edge measured at 5% and 95% relative peak height. For high-precision isotope ratio measurements, a wide, flat, stable peak is mandatory. In order to achieve the high mass resolution necessary to separate molecular interferences from elemental peaks in a multicollector instrument, a small source slit has to be selected.
The detector slit, however, is kept in the low-resolution setting. Through this combination of source and detector slits, individual detectors of the variable multicollector can be positioned such that only analyte ions enter the detector, and any interfering ions are not allowed to pass to the detector. Elements, where high mass resolution is required for accurate, interference-free analysis, are mainly in the low to medium mass range, e.g. Mg, Si, S, Ca, Cr and Fe. According to the systematics of the nuclear mass defect, the majority of molecular interferences in the low and medium mass range are heavier than the elemental species. A wide detector slit in all resolutions is the best choice since it guarantees the widest peak flatness at high resolving powers, which is a prerequisite for highly precise and accurate isotope ratio analyses.
Neptune Series instruments: Pioneering multicollector technologies, perfecting multicollector technology for geosciences and other discipline applications.
Thermo Scientific™ Neptune Plus ™ High Resolution Multicollector ICPMS:
- First with Retarding Potential Quadrupole Lenses (RPQ) for abundance sensitivity.
- First to introduce a reliable moveable collector array, over 500 built.
- First to report ultra-high-precision static isotope ratio measurements.
- First for high-resolution MC-ICP-MS, enabling measurement of Si, S, Ca, Fe, Ni, and many more isotopic systems.
- First with stable and linear SEM and then CDD ion counters.
Thermo Scientific™ Neptune XT™ High Resolution Multicollector ICP-MS:
- First with 1013Ω Amplifier Technology, extending the benefits of Faraday cup detectors to smaller sample amounts. Now available with gain calibration and tau correction.
- First for sensitivity – the Jet Interface offers the highest ICP-MS sensitivity available.