The role of NO-sensitized oxidation during the product-gas entrainment of a low-NO,,, multi-jet, natural gas burner is investigated. A detailed kinetic mechanism for the NO-sensitized oxidation of CH4, consisting of 483 reactions and 69 species, is used for the kinetic analysis. An eigenvalue-eigenvector decomposition is performed on normalized sensitivity coefficients to study the important reactions using principal component analysis (PCA), and the loadings corresponding to the largest eigenvalue are used to identify the reaction pathways of NO-sensitized oxidation. The main reaction pathway is most strongly affected by the temperature profile and equivalence ratio. Also, a reduced kinetic scheme of 110 reactions and 47 species is developed by eliminating reactions with small loadings. The temporal evolution of reactions is investigated using functional PCA, in which the functional loadings reflect the importance of reactions as a function of time. A discretization approach is used to perform the functional PCA. (c) 2005 Elsevier Ltd. All rights reserved.