Volatile organic compounds emitted from Scots pine and Norway spruce wood

Volatile organic compound (VOC) emissions from Scots pine and Norway spruce wood were evaluated in green and kiln-dried conditions using Micro-Chamber (µ-CTE™) air-sampling, thermal desorption, and GC–MS. A total of 411 specimens were tested to evaluate sampling distributions, effect of kiln drying, and the chemical composition of VOC emissions in detail. There was no significant difference in emissions between spruce heartwood and sapwood. The median total VOC emission rate from spruce was 93% lower than that from pine heartwood in green condition, whereas in the kiln-dried state, the emission was 98% lower. Compared with pine sapwood, the median emissions from spruce were 85% and 94% lower in green and kiln-dried conditions, respectively. Pine sapwood emitted 55% and 79% less VOC than heartwood in green and kiln-dried conditions. Except for pine sapwood, all groups exhibited positively skewed distributions. The skewness was particularly noticeable in the green pine heartwood sample, where the top 10% of VOC scores increased the mean VOC emission by 67%. Kiln drying had a substantial impact on VOC emissions. The median emission reduction due to drying amounted to 93%, 79%, and 80% for spruce, pine heartwood, and pine sapwood, respectively. A strong positive linear relationship was observed between the emissions in the green condition and the emission reduction caused by drying. Except for 3-carene, the emission profiles were similar among the tested groups.