Analysis of natural product remain challenging issues for analytical chemist, since natural products are complicated system
of mixture. The most popular methods of choice used for quality control of raw material and finished product are high
performance liquid chromatography (HPLC), gas chromatography (GC) and mass spectrometry (MS). The utilization of
FTIR-ATR (Fourier Transform Infrared-Attenuated Total Reflectance) method in natural product analysis is still limited.
This study attempts to expand the use of FTIR spectroscopy in authenticating Indonesian coffee powder.The coffee
samples studied were taken from nine regions in Indonesia, namely Aceh Gayo, Flores, Kintamani, Mandheling, Papua,
Sidikalang, Toraja, Kerinci and Lampung.The samples in the form of coffee bean from various regions were powdered .
The next step conducted was to determine the spectrum using the FTIR-ATR (Attenuated Total Reflectance) using ZnSe
crystal of 8000 resolution. Spectrum samples, then, were analyzed using chemometrics. The utilized chemometric model
was the principal component analysis (PCA) and cluster analysis (CA). Based on the chemometric analysis, there are
similarities between Aceh Gayo coffee with Toraja coffee, Mandailing coffee, Kintamani coffee and Flores coffee.
Sidikalang coffee has a similarity to Flores coffee; Papua coffee has a similarity to Sidikalang coffee; Lampung coffee has
a similarity to Sidikalang coffee, while Kerinci coffee has a similarity to Papua coffee.
Experiments on the Porch Swing Bearing of Michelson Interferometer for Low Resolution FTIR