Patent ID: 8389289

Claim:
A gas chromatograph apparatus comprising: (a) first storage means which stores, as a reference retention index, a retention index of a given substance with respect to a retention-index reference substance, the retention index of the given substance being obtained by gas chromatographic analysis using a normal column; (b) second storage means which stores, as a reference retention time, a retention time of the given substance obtained by normal gas chromatographic analysis using the gas chromatograph apparatus; (c) actual information acquisition means operable to acquire a current actual retention time and a current actual retention index of the given substance, based on data obtained by subjecting to gas chromatographic analysis a target sample containing the given substance and the retention-index reference substance added thereto; (d) status diagnostics means operable to diagnose a state of the apparatus and adequacy of analysis conditions, based on both a difference between the current actual retention index and the reference retention index stored in the first storage means and a difference between the current actual retention time and the reference retention time stored in the second storage means; (e) a diagnosis processing sub-section operable to calculate a time deviation value between the current actual retention time and the reference retention time and an index deviation value between the current actual retention index and the reference retention index, wherein a specific causal factor of abnormality in a gas chromatographic analysis is determined based on the time deviation value and the index deviation value; and (f) output means operable to output a result of the diagnosis comprising the specific causal factor by the status diagnostics means.