Analysis Of microcystin-LR Research Articles

Light-Initiated Imprinted Membrane-Based Biomimetic SERS Sensor toward Selective Detection of Trace MC-LR.

Microcystin-LR (MC-LR) is a severe threat to human and animal health; thus, monitoring it in the environment is essential, especially in water quality protections. Herein, in this work, we synthesize PVDF/CNT/Ag molecular imprinted membranes (PCA-MIMs) via an innovative combination of surface-enhanced Raman spectroscopy (SERS) detection, membrane separation, and molecular-imprinted technique toward the analysis of MC-LR in water. In particular, a light-initiated imprint is employed to protect the chemical structure of the MC-LR molecules. Furthermore, in order to ensure the detection sensitivity, the SERS substrates are combined with the membrane via the assistance of magnetism. The effect of synthesis conditions on the SERS sensitivity was investigated in detail. It is demonstrated from the characteristic results that the PCA-MIMs present high sensitivity to the MC-LR molecules with excellent selectivity against the interfere molecules. Results clearly show that the as-prepared PCA-MIMs hold great potential applications to detect trace MC-LR for the protection of water quality.

Analysis of microcystin-LR and nodularin using triple quad liquid chromatography-tandem mass spectrometry and histopathology in experimental fish

Microcystins (MCs) are hepatotoxic cyanobacterial metabolites produced sporadically in aquatic environments under favorable environmental conditions. Affinity of these toxins to covalently bind with protein phosphatases poses a challenge in their detection. Lemieux oxidation to release 2-methyl-3-methoxy-4-phenylbutyric acid (MMPB), a common moiety to all MCs congeners, has been used in detection of these compounds, however a lack of sensitivity has limited the usefulness of the method. In this study, modifications of the oxidation and solid phase extraction procedures, combined with a sensitive LC/MS/MS (liquid chromatography/mass spectrometry) detection, have resulted in 25 ng/g method detection limits in both liver and plasma samples. Samples harvested from six fingerling channel catfish (Ictalurus punctatus) dosed intraperitoneally with a sublethal MC-LR dose of 250 μg/kg were analyzed, and microcystin concentrations ranging from 370 to 670 ng/g in plasma and 566–1030 ng/g in liver were detected. Similarly, 250 μg/kg nodularin-dosed channel catfish fish were found to contain 835–1520 ng/g in plasma and 933–1140 ng/g in liver. Detection of the toxins in serum and liver combined with the presence of histopathological lesions consistent with these hepatocellular toxin in exposed fish and no positive findings in the control fish demonstrates the usefulness of this analytical procedure for the diagnosis of suspected algal toxicity cases.

Evaluation of analytical approaches linked to high performance liquid chromatography for analysis of microcystin-LR in natural water systems: effects of column and mobile phase gradient

A simple approach was carried out to study the effects of various parameters on high performance liquid chromatography (HPLC) performance of microcystin-LR (MC-LR) analysis in samples from some reservoirs and rivers in Taiwan under simulation conditions. Nature of column and its packing affected the instrument sensitivity. Varied column length indicated the longer column enhanced (C18, 5 μm, 4.6 × 150 mm) HPLC performance. Studies on mobile phase found that ratio and concentration of the mobile phase gradient greatly influenced the peak shape, retention time, and optimal conditions of mobile phase were set at acetonitrile and 0.01M ammonium acetate (30:70). Different compounds were added to mobile phase and their contribution to HPLC spectra was reported. Detection limits were carefully measured and reported. These investigations provide simple and important information that may be applied to HPLC performance for microcystin analysis from natural water systems.