Institute for Atmospheric and Earth System Research of the University of Helsinki invites tenders for a proton-transfer-reaction mass spectrometer for measuring volatile and low-volatile organic compounds at a coastal measurement site.

Institute for Atmospheric and Earth System Research of the University of Helsinki invites tenders for a proton-transfer-reaction mass spectrometer for measuring volatile and low-volatile organic compounds at a coastal measurement site.

The instrument must meet the following requirements:

a) Resolving power > 8000

b) Mass range extending at least up to m/z 1000

c) H3O+ ion source.

d) High-sensitivity for volatile organic compounds: > 20 000 cps/ppb for acetone and > 10 000 cps/ppb for a-pinene (C10H16).

e) Low detection limit: < 1 ppt (30 s, 3-sigma) for a-pinene

f) Linearity up to around 100 ppb

g) Inlet design that allows also to measure semi-volatile and low-volatile organic compounds with the H3O+ ion source.

h) Can be used both in laboratory measurements and ambient monitoring in field conditions.

i) The instrument must be easily transportable and its overall weight should be < 200 kg.

j) Manufacturer must provide a comprehensive analysis and data acquisition software.