Investigation of applicability of a mid-infrared spectroscopic method using an attenuated total reflection accessory and a new near-infrared transmission method for determination of faecal fat
M. Volmer et al., Investigation of applicability of a mid-infrared spectroscopic method using an attenuated total reflection accessory and a new near-infrared transmission method for determination of faecal fat, ANN CLIN BI, 38, 2001, pp. 256-263
In many laboratories, the titrimetric method of Van de Kamer is used for th
e analysis of faecal fat content of patients suspected of steatorrhoea. We
investigated the applicability of a mid-infrared (MIR) spectroscopic method
, using an attenuated total reflection (ATR) accessory, and a new near-infr
ared (NIR) spectroscopic method. For the NIR method, sealed plastic bags co
ntaining the stool samples were used as transmission cells. Standardization
was obtained using a previously described MIR method, with a NaCl flow-cel
l, as reference method. Partial least-squares regression was used for the c
alibration of each method. Full cross-validation of the calibration set was
used for the internal validation of each method. Fifteen per cent of the s
tool samples could not be estimated with the ATR method within reasonable a
ccuracy limits compared with the reference. The standard error of predictio
n of the NIR method was 1.1 g/dL. We conclude that the new NIR method is a
promising technique for routine use. However. further experiments need to b
e done with triplicate measurements of each sample and the use of an extern
al validation set.