The data, from automatic measurements by the relevant sensors, were stored in a data logger and transferred to land-based PC systems on a regular basis. Discrete water samples were collected (WS 316 VAR autosampler; WaterSam, Germany) at 6 pre-selected or on-line triggered time intervals/geographical locations (Figure 1). The discrete water samples supplied material for phytoplankton analysis, as well as chlorophyll a and nutrient determination. The discrete water samples were collected during the daytime, usually on the voyage from Karlskrona to Gdynia, which GW-572016 manufacturer takes < 10 h.

The WaterSam autosampler is equipped with a cooler, so the samples could be stored at 4 °C until the port of destination, where they were immediately transferred to a land laboratory for further processing. Discrete water samples were collected fortnightly on average, although

the time interval varied depending on the environmental situation. The analytical methods conformed to the HELCOM COMBINE monitoring programme ( HELCOM 1997). Within this module, phytoplankton structure, abundance and biomass analyses were conducted on discrete samples; algal toxins were determined and the toxicity of water was assayed on test animals. Phytoplankton taxa, abundance and biomass were determined according to the HELCOM guidelines selleck products (HELCOM 1997). A standard procedure of hepatotoxin analysis was applied with regard to algal toxins (Meriluoto & Codd 2005). Environmental samples were passed

through GF/C Whatman filters. The material retained on the filters was treated with 90% methanol, homogenized in an ultrasonic bath for 15 min and then treated for 1 min with an ultrasonic disruptor equipped with a microtip probe. The aliquots were centrifuged for 10 min (10000 × g). High performance liquid chromatography (HPLC, Waters, Milford, MA, USA) with a diode array detector 3-oxoacyl-(acyl-carrier-protein) reductase (isocratic conditions; a single analysis took 10 min) was used to measure the nodularin concentration. The structure of the nodularin present in the cyanobacterial bloom material was confirmed using LC-MS/MS. The analytical system consisted of a QTRAP5500 MS/MS with a turbo-ion spray (Applied Biosystems MDS Sciex, Concord, ON, Canada) and an Agilent 1200 HPLC (Agilent Technologies, Waldbronn, Germany). Separation was performed on a Zorbax Eclipse XDB-C18 (4.6 × 150 mm; 5 μm) (Agilent, USA) at 35 °C. Gradient elution was with a mixture of mobile phase A (5% acetonitrile containing 0.1% formic acid) and B (100% acetonitrile containing 0.1% formic acid). Mass spectra were acquired over a range of 50–1100 Da with a scan time of 1.0 s. The QTRAP instrument was operated in positive ion mode. Structures were elucidated using collision-induced dissociation (CID) with a collision energy ranging from 50 eV to 60 eV. Data were acquired and processed using Analyst QS 1.5.1 software.