A Quantitative Method of Analysis for Sterol Glycosides in Biodiesel and FAME Using GC‐FID

Abstract

Sterol glycosides (SG) are known to cause filter blocking problems in biodiesel use. The extraction and quantitative analysis of SG is difficult due to its low problematic concentration and its compatibility with biodiesel. The purpose of this study is to develop a method to quantify SG in FAME and biodiesel using gas chromatography and other equipment found in laboratories performing routine biodiesel analyses. SG was isolated from FAME using n‐dodecane, acidification and cold soaking, followed by cold centrifugation at −8 to −15 °C. The solids obtained were further separated by phase partition with a Folch wash, followed by a final n‐dodecane rinse. This solution was analyzed by GC‐FID using the operating conditions outlined in ASTM D6584. A calibration curve for SG was produced and a first order fit gave a value of r2 = 0.992. Reproducibility tests were performed on soybean FAME and B100 canola biodiesel samples spiked with SG. The recovery of SG by the new method was found to be 99 % for soy FAME with a standard deviation of 0.7 and 100 % for B100 canola with a standard deviation of 3.5 %. The reproducibility based on two standard deviations of the predicted concentration for all 12 spiked samples studied in this work was 2.4 ppm.

The in-process removal of sterol glycosides by ultrafiltration in biodiesel production

“…Centrifugation was only used in analyzing SG in FAME using the method described by Montpetit and Tremblay (2016). Temperature controlled centrifugation was carried out using a Hermle Z400K centrifuge, equipped with a Hermle 220.97 rotor (28° fixed angle, max radius 9.5cm and a max speed of 6000 rpm, equivalent to 3820 ×g).…”

“…SG was decompatibilized from the methanol evaporated FAM E according to the method developed by Montpetit and Tremblay (2016), and the isolated precipitates were analyzed by GC-FID using the method outlined in ASTM D6584. The SG concentration in each sample was determined by measuring the area within the range of relative retention times (RRT) of 1.21-1.3.…”

“…The area from the relative retention time of 1.21 to 1.3 was measured using multiple peak integration and divided by the area of the tricaprin internal standard. The calibration curve used in this work was generated as described in Montpetit and Tremblay (2016) and had an R 2 of 0.9974.…”

“…FAME samples from the membrane retentates and permeates produced using the experimental conditions listed in Section 2.3 were analyzed using the method described by Montpetit and Tremblay (2016). The separation factor (SF) for each run was calculated using Equation 1 as follows:…”

Silica Based Material as a Potential Adsorbent in Reducing Sterol Glucoside Level in Palm Oil Biodiesel

“…Isolation of SGs from palm based biodiesel method was done according to Montpetit A. [11] with minor modification. 15 mL of biodiesel was added into 15 mL heptane in 50 mL centrifuge tube.…”