Syftet med denna studie var att utveckla en separations- och analysmetod för identifiering av icke-volatila substanser från strån och rötter av de gräsliknande växterna Cyperus rotundus och Panicum repens. För analysen användes högpresterande vätskekromatografi (HPLC) och ultrahögpresterande vätskekromatografi (UHPLC) med en opolär stationär fas (RP-HPLC) med ultraviolett ljus (UV) och elektrosprej masspektrometri detektion (ESI-MS). Proverna extraherandes med hjälp av ultraljuds assisterad extraktion (UAE) och koncentrerades med solid fasextraktion. Två olika metoder användes vid extraktionen antingen sänktes gräset i 10 ml acetonitril två gånger eller så direkt i 20 ml acetonitril. På grund av svårigheten att uppnå reproducerbarhet vid extraktion med samma metod kunde ingen slutsats om någon metods fördelar dras. Under utvecklingen av HPLC metoden testades två olika elueringsmedel metanol och acetonitril i kombination med MilliQ-vatten. Den slutgiltiga metoden börjar med en mobilfas innehållande 70% metanol och 30% vatten under 5 min för att sedan öka till 100% metanol under 10 minuter innan mobilfasen hålls vid 100% metanol under 25 minuter. Med UV-detektorn kräver identifikation av de okända komponenterna krävde kända referenser. Vidare undersökningar genomfördes därför med masspektrometri. Dock så var det begränsad tid kvar för undersökningar med MS så få körningar kunde genomföras, därav kunde inte analyterna analyseras tillräckligt för att kunna identifiera komponenterna från Cyperus rotundus. Vidare analyser med MS samt även kopplad MSMS där spektrum kan jämföras med en databas för identifikation skulle underlätta identifikationen. / The aim of this study is to develop an analysis method for the separation and identification of non-volatile substances from the Cyperus rotundus and- Panicum repens roots and shoots. For the analysis reversed phase high performance liquid chromatography (HPLC) and ultra-high performance liquid chromatography (UHPLC) methods where used. First an UV detector was used in combination with the HPLC setup and in the later stages access to an electrospray ionization ion trap mass spectrometer was enabled for coupling to UHPLC. The samples were extracted with ultrasound assisted extraction (UAE) and the concentrated with solid phase extraction (SPE). Two different extraction methods were attempted one where the graminoid plants where submerged in 10 ml acetonitrile twice and the other with 20 ml directly. Due to the difficulty of reproducing result between different extraction batches no conclusion on whether either method is superior could be made. For the development of the HPLC method methanol or acetonitrile was used in combination with ultrapure (MilliQ) water. The final eluationprogram was 70% methanol and 30% MilliQ water for five minutes, increasing linearly over 10 minutes to 100% methanol and then running for 25 minutes. With the UV detector no identification was possible, so further investigations were performed with UHPLC-MS for analysis of the mass of the analytes. Due to time limitations only a few MS analyses on the Cyperus rotundus were performed, and only a few masses could be estimated. Further runs of the samples need to be performed in combination with coupled MSMS to be able to identify the analytes in the samples.

Torpedograss (Panicum repens) was first observed in Lake Okeechobee in the 1970s and appears to have displaced an estimated 6,400 ha of native plants, such as spikerush (Eleocharis cellulosa), where inundation depths are often less than 50 cm. Two series of studies evaluated substrate exposure and water depth influences on torpedograss establishment and competitiveness. Results revealed that fragments remain buoyant for extended periods and so facilitate dispersal. Once anchored to exposed substrate fragments can readily root and establish. Subsequently, torpedograss thrives when subjected to inundations to 75 cm and survives prolonged exposure to depths greater than 1 m. These findings suggest that fluctuating water levels contribute to torpedograss dispersal and colonization patterns and that low water levels increase marsh area susceptible to invasion. The competition study found that spikerush grown in monoculture produces significantly more biomass when continually inundated to shallow depths (10 to 20 cm) than when subjected to drier conditions (-25 cm) or greater inundations (80 cm). In contrast, torpedograss establishes more readily on exposed substrate (-25 to 0 cm) compared to inundate substrates. During the first growing season biomass production increases as substrate exposure interval increases. However, during the second year, established torpedograss produces more biomass when grown on intermittently wet (0 cm) compared to permanently dry (-25 cm) or intermittently inundated (10 cm) substrates. No difference in production was observed between substrates permanently inundated (10 cm) and any other regime tested. During the first two years of torpedograss invasion, regardless of treatment, spikerush suppresses invasion and torpedograss had little effect on established spikerush, indicating that spikerush-dominated areas are capable of resisting torpedograss invasion. Even so, disturbances that might cause mortality of long hydroperiod species, such as spikerush, may create open gaps in the native vegetation and thus facilitate torpedograss establishment and expansion.