Breath sampler

A method for measuring the concentration of a selected analyte in a sample of essentially once-exhaled breath provided by a subject, comprising the steps of:

• prefiltering air inhaled by the subject from the ambient atmosphere with a filter capable of significantly removing such of the selected analyte as is present in the ambient air, to thereby ensure accurate subsequent measurement of the concentration of the selected analyte in the sample comprising the subject's essentially once-exhaled breath;
• passing the breath sample directly through a selected sorbent example capable of sorbing the selected analyte therefrom, wherein the sorbent element is formed and disposed to present a low impedance flow passage to the breath sample passed therethrough;
• determining the volume of the breath sample from which analyte has been sorbed by the sorbent example;
• desorbing the sorbed analyte from the sorbent element;
• measuring an amount of the selected analyte desorbed from the sorbent;
• and
• determining a concentration of the selected sorbent in the determined volume of essentially once-exhaled breath provided by the subject.

A method for measuring the concentration of a selected analyte in a multi-breath sample of essentially once-exhaled breath from a subject, comprising the steps of:

• passing a sample comprising multiple breaths, each being essentially once-exhaled, from the subject directly through a selected sorbent capable of retaining at least one analyte present in said sample;
• desorbing the at least one retained analyte from the sorbent;
• measuring a volume of said breath sample;
• and
• thereby determining a concentration of the desorbed analyte in the multiple breaths provided by the subject.

Apparatus for collecting from a subject a sample of essentially once-exhaled breath containing a selected analyte, for subsequent determination of a concentration of the selected analyte in the sampled exhaled breath, comprising:

• a tubular conduit having a first opening to receive a flow-through of essentially once-exhaled breath from the subject, a second opening and a third opening to permit inhalation of ambient air by the subject;
• and
• means for collecting a sample of the selected analyte from said essentially once-exhaled breath, connected to said second opening,
• wherein the second and third openings contain respective first and second valve means to permit only said essentially once-exhaled breath to pass through the sample collection means.