Determination of biogenic component in liquid fuels by the 14C direct LSC method by using quenching properties of modern liquids for calibration

Abstract

b s t r a c tThe fraction of biogenic component within various types of materials that can be used as fuels for energy production and transport can be determined by measuring their 14 C activity. The method is based on different 14 C signatures of the biogenic and the fossil components: while the biogenic component reflects the modern atmospheric 14 C activity, no 14 C is present in fossil fuels. A direct measurement of the 14 C content in liquid fuel by liquid scintillation counter is a simple and fast technique but has a main disadvantage: different liquid colors cause different quenching properties and affect the measurement efficiency. We propose a new evaluation technique that uses liquids of different colors to construct modern and background calibration curves. Various binary mixtures of biogenic liquids have been used to verify the relation between the count rate and the quenching parameter. Mixtures of a biogenic and a 14 C-free liquid demonstrated the potential of the proposed technique for determining the biogenic fraction of a mixture.

High-Precision Biogenic Fraction Analyses of Liquid Fuels by 14C AMS at HEKAL

“…For example, the color of fuels causes different quenching properties in the scintillation cocktail and affects the measurement efficiency (Doll et al 2017). Based on the measurement of radiocarbon content as 14 C/ 12 C and 14 C/ 13 C isotope ratio, the biogenic fraction is also measurable by accelerator mass spectrometry (AMS), where the number of 12 C, 13 C, and 14 C atoms can be counted directly (Bronić et al 2017). In this study, the biobased content of reference samples from the Hungarian oil company, MOL Nyrt., with predetermined mixing ratios were measured by the EnvironMICADAS AMS at the Hertelendi Laboratory of Environmental Studies (HEKAL) (Molnár et al 2013).…”

Mass Spectrometric and Functional Aspects of Drug–Protein Conjugation

“…While LSC is perhaps the least complex and cheapest method, limits of detection and light frequency disruptions may hamper identification of radioactive material at low concentrations. Although AMS does enable more precise analysis from smaller sample volumes, instrumental platforms are very expensive . Therefore, radiometric analysis in combination with SDS–PAGE is the most widely used method for the detection of drug–protein adducts in complex systems. − Although there are clear advantages to using radiometric detection, the cost and storage/disposal of radioactive material make its use in most research facilities limited.…”

Liquid Scintillation Counting Method for the Refinery Laboratory-Based Measurements of Fuels to Support Refinery Bio-Feed Co-Processing

“…20 In addition to having to consider the background and quenching effects of the sample matrix, the carbon content of each sample must be measured. 25,30,31 LSC only measures the radioactive decays of the 14 C in the sample, which results in only the percent carbon in the sample that is from a biological source being measured. When converting the measured counts per minute (CPM) value of a sample to percent biocarbon, the mass of carbon in the sample vial needs to be measured, requiring a carbon content measurement to be conducted for each sample.…”

“…The scintillator converts the energy that is given off through the radioactive decay of the 14 C into many photons through a complex electromagnetic mechanism, which is then detected by photomultiplier tubes . The process of either photon generation or photon detection can easily be hindered by the presence of a large variety of different species present in the sample through either chemical or color quenching. − Along with quenching, certain compounds can fluorescence, which can increase background levels and background variability . The elaborate sample preparation methods in D6886-20 are done to remove these issues by converting all samples into a uniform matrix, benzene for Method C.…”

“…The primary concern for spiking experiments is lab and sample contamination requiring much care to be taken to prevent this from happening . In addition to having to consider the background and quenching effects of the sample matrix, the carbon content of each sample must be measured. ,, LSC only measures the radioactive decays of the 14 C in the sample, which results in only the percent carbon in the sample that is from a biological source being measured. When converting the measured counts per minute (CPM) value of a sample to percent biocarbon, the mass of carbon in the sample vial needs to be measured, requiring a carbon content measurement to be conducted for each sample. ,, For ASTM D6866-20 method C, the sample is converted to a pure compound, i.e., benzene, eliminating the need to measure the carbon content of the sample as it can easily be calculated from the amount of benzene added to the sample vial .…”