Capillary absorption spectrometer and process for isotopic analysis of small samples

摘要

A capillary absorption spectrometer and process are described that provide highly sensitive and accurate stable absorption measurements of analytes in a sample gas that may include isotopologues of carbon and oxygen obtained from gas and biological samples. It further provides isotopic images of microbial communities that allow tracking of nutrients at the single cell level. It further targets naturally occurring variations in carbon and oxygen isotopes that avoids need for expensive isotopically labeled mixtures which allows study of samples taken from the field without modification. The method also permits sampling in vivo permitting real-time ambient studies of microbial communities.

主权项

1. A method for analyzing low-volume target analytes, comprising the steps of:
introducing a turbulent gas, liquid, or aerosols through a medium across the propagation path of a laser excitation beam introduced into a capillary infrared absorption device in a capillary absorption spectrometer to provide a picomolar detection sensitivity therein; ablating a solid sample containing at least a picomolar quantity of the target analytes therein with a pulsed UV excitation beam to convert the sample into sample particulates; transferring the ablated sample particulates to a catalytic reactor; converting the ablated sample particulates in the catalytic reactor into a molecular gas; transferring the molecular gas from the catalytic reactor through a transfer device at a first higher pressure into the capillary infrared absorption device at a second lower pressure; and analyzing the molecular gas in the capillary absorption device with an infrared absorption detector to determine isotopic ratios of the target analytes in the sample at the picomolar detection sensitivity.