In literature, methanol has been used as a non-destructive solvent for the cocaine extraction from euro banknotes. . Different percentages of methanol were used to extract cocaine 50%, 70%, 80%, 90% and 100%. In addition, PBS was also used to extract cocaine and each note was preceded by a second extraction with methanol for the matrix effect. Subsequently, the extraction by methanol, the euro bank note was washed by 20 ml Milli-Q water/ 5ml methanol. The extracted solution was diluted by different dilution, 1:10, 1:50, 1:100, 1:500, 1:1000 and 1:10000 with Milli-Q water. Methanol has been used as a solvent for cocaine extraction form banknotes. It was reported as a non-destructive method unlike other solvents like chlorinated solvents and …show more content…
Then the bank note was washed by either 20 ml Milli-Q water or 5 ml methanol. The bank note was dried and a second extraction was carried out to calculate the percent recovery. At the primary extraction, different concentration of methanol and PBS were examined. 100 %, 90%, 80%, 70%, 50% methanol: Milli-Q water and PBS were the solvent for extraction. The second extraction was mainly by 100 % methanol. The percent recovery was measured by dividing the amount from the second extraction on the total amount extracted multiple by 100. By using extraction solvent of 100 % methanol, the percent recovery was between 1-5 %, with mean value 3.72 %. That is considered slightly higher percentage when compared with the reported from Esteve et al. With increasing the dilution of Methanol, a slight increase reported in the percent recovery mean value between 12.17 – 16.33 %. PBS solution can be used for extraction of cocaine, although it has very high recovery percent of an average of 20.91%. Which means PBS can be used for extraction, but not for complete extraction in the note. One of the highest contamination levels on of the paper notes were extracted by