Effects of measurement technique and sample preparation on NIR spectroscopy analysis of livestock slurry and digestates

摘要: Near infrared spectroscopy (NIRS) was used to analyse livestock slurries and digestates. The purpose evaluate the influence of sample preparation, reading set-up temperature during NIR scanning on digestates slurry samples. To obtain accurate reproducible values total solids (TS), kjeldahl nitrogen (TKN), ammoniacal (TAN) volatile fatty acids (VFA) contained in dairy pig digestate, a 36 samples were analysed from different farms Lombardy, Italy. Three preparations (filtration, homogenisation raw control), two set-ups (petri dish optical fibre) three temperatures (10, 25 35 °C) tested scanning. Results showed that analysis by spectrophotometry is influenced preparation. Both filtered homogenised generally higher correlations (r2) ratio standard error performance deviation (RPD) (0.79   0.98 2.26   6.99 for samples; 0.30   0.97 1.24   6.31 samples) than (0.03   0.95 1.05   4.73), but better preparation filtration. Spectral acquisition through petri dishes slightly more fibre. No observable effects spectral caused altering range 10–35 °C.