Drugs of abuse and tranquilizers in Dutch surface waters, drinking ...

RIVM Report 703719064analytical run the standards were diluted 10 times with Ultra pure water(Millipore, MA, USA) resulting in a mix of 90% water and 10% methanol. For thedeuterated standards the same procedure was followed except that they wereadded to all the calibration standards at a concentration level of 72 pg/µL, toassure no false positives are reported when adding the deuturated analogues.The purity of the deuterated analogues was investigated by creating “pseudo”extracts, spiked at the concentration level of 72 pg/µL increasing to 16 timesthis level to achieve sufficient sensitivity in case impurities were encountered.For three deuterated compounds (purity certificate listed in Table C.1) nondeuturatedanalogues were detected in the standard solutions supplied (seeTable C.2).Table C.1. Given certified puritynumber Compound Lipomedcertified purity1 6-monoacetylmorphin-d3 98.72 benzoylecgonine-d3 99.633 Cocaine-d3 99.3Table C.2. Contribution (expressed as % impurity ) of non deuturated analoguesin different solutions of deuterated standards of table C.1Number 1 2 3ug/ int std in 6-monoacetylmorphine % benzoylecgonine % impurity cocaineextract [ng]impurity [ng][ng]%impurity1 72 0.1 0.14% 0.12 0.17% 0.12 0.17%2 144 0.18 0.13% 0.14 0.10% 0.11 0.08%4 288 0.49 0.17% 0.4 0.14% 0.15 0.05%8 576 1.2 0.21% 0.79 0.14% 0.37 0.06%16 1152 2.6 0.23% 1.5 0.13% 0.75 0.07%Averageimpurity0.17% 0.13% 0.08%Identification and confirmationIdentification of the compounds was performed using the accurate mass of theprotonated molecule within a mass window of 5 ppm together with one production (nominal mass). The retention times of the compounds were compared tothose of the compounds in thecalibration standard solution of the final analysis.For confirmation of target compounds, LC relative retention time criteria(retention time window