Motor oil classification based on time-resolved fluorescence.

Taotao Mu,Fandong Meng,He Chen,Yinchao Zhang,Pan Guo,Siying Chen,Sabato D'Auria

doi:10.1371/journal.pone.0100555

Taotao Mu, Fandong Meng + Show 5 more

Open Access

https://doi.org/10.1371/journal.pone.0100555

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Abstract

A time-resolved fluorescence (TRF) technique is presented for classifying motor oils. The system is constructed with a third harmonic Nd:YAG laser, a spectrometer, and an intensified charge coupled device (ICCD) camera. Steady-state and time-resolved fluorescence (TRF) measurements are reported for several motor oils. It is found that steady-state fluorescence is insufficient to distinguish the motor oil samples. Then contour diagrams of TRF intensities (CDTRFIs) are acquired to serve as unique fingerprints to identify motor oils by using the distinct TRF of motor oils. CDTRFIs are preferable to steady-state fluorescence spectra for classifying different motor oils, making CDTRFIs a particularly choice for the development of fluorescence-based methods for the discrimination and characterization of motor oils. The two-dimensional fluorescence contour diagrams contain more information, not only the changing shapes of the LIF spectra but also the relative intensity. The results indicate that motor oils can be differentiated based on the new proposed method, which provides reliable methods for analyzing and classifying motor oils.

Highlights

Motor oils, as products of petroleum refinery, are irreplaceable in car industry
0.2 Influence of gate delay time (GDT) on Fluorescence Spectra The normalized LIF spectra of different GDT (5 ns, 20 ns, 35 ns, 50 ns, 65 ns, and 75 ns) of oil samples are presented in Figure 3 (The data of oils can be found in Data S1)
0.3 Contour Diagrams of time-resolved fluorescence (TRF) Intensities of Motor Oils contour diagrams of TRF intensities (CDTRFIs) are constructed based on the time-character of LIF of motor oils (Figure 4, The data of oils can be found in Data S1)

Summary

Introduction

As products of petroleum refinery, are irreplaceable in car industry. They are used to protect the engine from many physically and chemically related malfunctions like heating, corrosion and contamination [1,2]. Due to the large variations in price of motor oils, cheap substituent products instead of more expensive petroleum products have been used by some profitdriven businesses to maximize the interest. It arisen the question about quality authentication [1]. Sample preparation is time consuming in the way described above.

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