The occurrence in wastewater of pharmaceuticals, drugs of abuse, and the metabolites
produced through the use of such compounds, is becoming a question of concern. The
recreational abuse of illicit compounds in South Africa has increased tremendously over the
past years and is currently a serious problem among the youth. Data on the use of illicit
drugs and the amounts consumed is limited to information coming from law enforcement
agencies, rehabilitation centres, and self-reported cases. Thus, an objective means of
measuring the actual drug use of a specific geographical area needs to be developed. In this
study, a method was developed to measure trace amounts of drug metabolites, including
11-nor-9-carboxy-Δ9-THC, benzoylecgonine, codeine, morphine, and 6 monoacetyl
morphine in wastewater. The Daspoort treatment plant—a facility serving the Pretoria West
and the Hatfield areas—was selected. An appropriate sampling procedure and sample pretreatment
was employed to yield the best resolution and separation possible for the
selected analytes. Sample pre-treatment involved the derivatization of analytes with
methyl-N-tert-butyldimethylsilyltrifluoroacetamide (MTBSTFA), pentafluoropropanol
(PFPOH) and propionic anhydride (PA), respectively. The samples were prepared in
accordance with the method of standard addition. A GCxGC/TOF-MS analysis was
performed and a weekly concentration profile for each analyte was produced. The
measured concentration obtained for each analyte was corrected for flow to ensure
accurate estimation of the total weight of parent compound per day. The total parent
compound weight measured confirms that the abuse of illegal substances is occurring in the
population. The results obtained in the study provide further evidence for the fact that drug
abuse in the Daspoort area must be urgently addressed.
Die voorkoms van medisyne, dwelms en hul metaboliete in afvalwater is steeds
kommerwekkend. Die misbruik van onwettige middels in Suid-Afrika het geweldig
toegeneem oor die afgelope paar jaar en is 'n ernstige probleem onder die jeug in 'n sosiale
omgewing. Inligting oor die gebruik van onwettige dwelms is sterk afhanklik van
wetstoepassingsagentskappe, inligting van rehabilitasiesentrums en self-gerapporteerde
gevalle. Metodes word benodig om ‘n objektiewe opname van die werklike dwelmgebruik
van ‘n geografiese area te kan doen. Tydens hierdie studie is 'n metode ontwikkel om
spoorvlakke van dwelm-metaboliete in afvalwater te meet. Hierdie metaboliete sluit in: 11-
nor-9-karboksie-Δ9-THC, bensoïelecgonine, kodeïen, morfien en 6 monoasetielmorfien. Die
Daspoort Waterwerke Fasiliteit was gekies en bedien die Pretoria-Wes en die Hatfield
metropolitaanse areas. Die mees toepaslike monsterneming asook monster-behandeling vir
die geselekteerde analiete, is uitgevoer om die beste instrumentele analise moontlik te
lewer. Monster behandeling behels die derivatisering van analiete met Metiel-N-tertbutieldimetielsilieltrifluoroasetamied
(MTBSTFA), Pentafluoropropanol (PFPOH) en
propionsuuranhidried (PA). Die monsters is geanaliseer in ooreenstemming met die metode
van standaard addissie. 'n GCxGC / TOF-MS analise is uitgevoer en 'n weeklikse
konsentrasie-profiel vir elke analiet is gevind. Die konsentrasie vir elke analiet is aangepas
vir vloei om sodoende ‘n akkurate skatting van die totale massa van elke dwelm per dag te
bekom. As daar na die resultate gekyk word, is die misbruik van onwettige middels
kommerwekkend. Hierdie studie bevestig die erns waarmee die misbruik van dwelms in die
Daspoort-area aangespreek moet word.
