An apparatus for concentrating and collecting one or more analytes in a
flowing liquid stream of a carrier solvent composed of one or more
solvent components is provided, which includes a transfer tube which
forms a bore having an inlet and an outlet, the inlet being adapted to
accept the flowing liquid stream, and the outlet being adapted to form
continuously replaced, hanging droplets of the liquid stream, and a
collection device mounted below the outlet of the transfer tube for
collecting the droplets. The apparatus includes a device for heating the
liquid stream in the transfer tube to a temperature sufficient to cause
partial evaporation of the carrier solvent from the hanging droplets but
not exceeding the boiling point of the carrier solvent, and a device for
heating the collection device to a temperature sufficient to cause
further evaporation of the carrier solvent from the collected droplets.
Also provided is a method for concentrating and collecting one or more
analytes in a flowing liquid stream of a carrier solvent composed of one
or more solvent components. The method includes the steps of introducing
the liquid stream into a transfer tube which forms a bore having an inlet
and an outlet, the inlet being adapted to accept the flowing liquid
stream, and the outlet being adapted to form continuously replaced,
hanging droplets of the liquid stream, and heating the liquid stream in
the transfer tube while controlling the temperature of the liquid stream
in the transfer tube to be sufficient to cause partial evaporation of the
carrier solvent from the hanging droplets without exceeding the boiling
point of the carrier solvent. The method allows the droplets to dislodge
from the outlet, and the droplet is collected on a collection device
mounted below the outlet of the transfer tube. The collection device is
also heated to a temperature sufficient to cause further evaporation of
the carrier solvent from the collected droplets.