scholarly journals Improved Method for the Determination of Anatoxin-a and Two of Its Metabolites in Blue-Green Algae Using Liquid Chromatography with Fluorescence Detection

2005 ◽  
Vol 88 (6) ◽  
pp. 1741-1747 ◽  
Author(s):  
Dorothea F K Rawn ◽  
Benjamin P-Y Lau ◽  
Barbara Niedzwiadek ◽  
James F Lawrence
Keyword(s):  
Liquid Chromatography ◽  
Green Algae ◽  
Fluorescence Detection ◽  
Background Noise ◽  
Degradation Products ◽  
Food Supplements ◽  
Primary Amines ◽  
Algal Toxins ◽  
Simple Method ◽  
Blue Green Algae

Abstract Anatoxin-a, a neurotoxin produced by blue-green algae (BGA) species, can cause death to exposed organisms. In North America, BGA are harvested and sold as food supplements, some of which contain elevated levels of other algal toxins, such as microcystins. Concern that elevated levels of anatoxin-a also may be present in BGA food supplements has led to the development of a simple method to determine the presence of anatoxin-a in BGA. Some researchers have successfully analyzed this compound using liquid chromatography with fluorescence detection by forming a fluorescent derivative with 4-fluoro-7-nitrobenzofurazan (NBD-F) in water and phytoplankton extracts. With this method, the background noise is high in BGA extracts due to the presence of co-extractives. Addition of o-phthaldialdehyde (OPA) and mercaptoethanol to the extract before addition of the NBD-F resulted in the successful removal of primary amines from the background noise when the NBD-F derivatives were detected with fluorescence. Improved chromatograms were obtained when extracts were cleaned up in this manner, leading to a lower detection limit (approximately 50 μg/kg) for anatoxin-a. The detection limits obtained for the 2 degradation products dihydroanatoxin-a and epoxyanatoxin-a in BGA extracts were similarly low (55 and 65 μg/kg, respectively).

Anatoxin-a and Its Metabolites in Blue-Green Algae Food Supplements from Canada and Portugal

2007 ◽  
Vol 70 (3) ◽  
pp. 776-779 ◽  
Author(s):  
DOROTHEA F. K. RAWN ◽  
BARBARA NIEDZWIADEK ◽  
BENJAMIN P.-Y. LAU ◽  
MARTIN SAKER
Keyword(s):  
Mass Spectrometry ◽  
Green Algae ◽  
Fluorescence Detection ◽  
Attention Deficit Disorder ◽  
High Performance ◽  
Transformation Product ◽  
The United States ◽  
Food Supplements ◽  
Health Food ◽  
Blue Green Algae

Blue-green algae and spirulina are marketed in health food stores and over the Internet as food supplements in Canada, the United States, and Europe. The reported benefits of consuming these products include improved digestion, strengthening of the immune system, and relief from the symptoms of attention deficit disorder. Some of these products have been found to contain elevated concentrations of microcystins, which are known hepatotoxins. In addition to producing microcystins, Anabaena sp. and Aphanizomenon sp. also produce the potent neurotoxin anatoxin-a. Samples of food supplements containing blue-green algae and spirulina were collected in Portugal and from urban centers across Canada in 2005. Extracts of these supplements were analyzed to determine the presence and concentrations of anatoxin-a and its two main metabolites, dihydroanatoxin-a and epoxyanatoxin-a. Initial analyses were performed using high-performance liquid chromatography (HPLC) with fluorescence detection, and confirmation required the use of LC with tandem mass spectrometry (LC-MS-MS). The HPLC with fluorescence detection indicated no anatoxin-a, but four samples were suspected to contain either dihydroanatoxin-a or epoxyanatoxin-a at 0.1 to 0.2 μg/g. LC-MS-MS results, however, indicated no trace of either transformation product in any sample analyzed. The detection limits for anatoxin-a, dihydroanatoxin-a, and epoxyanatoxin-a were similar for both fluorescence detection (0.2 to 0.3, 0.4 to 1.4, and 0.2 to 1.5 pg on the column, respectively) and mass spectrometry (0.3 to 1.5, 0.3 to 0.8, and 0.5 to 0.8 pg on the column, respectively). Because of the higher specificity of the LC-MS-MS analysis, all tested food supplement samples were considered free of anatoxin-a and its transformation products.

Rapid surface plasmon resonance immunobiosensor assay for microcystin toxins in blue-green algae food supplements

Talanta ◽  
2011 ◽  
Vol 84 (3) ◽  
pp. 638-643 ◽  
Author(s):  
Tatiana Vinogradova ◽  
Martin Danaher ◽  
Andrew Baxter ◽  
Mary Moloney ◽  
Danielle Victory ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Green Algae ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Food Supplements ◽  
Blue Green Algae

scholarly journals Comparison of Liquid Chromatography/Mass Spectrometry, ELISA, and Phosphatase Assay for the Determination of Microcystins in Blue-Green Algae Products

2001 ◽  
Vol 84 (4) ◽  
pp. 1035-1044 ◽  
Author(s):  
James F Lawrence ◽  
Barbara Niedzwiadek ◽  
Cathie Menard ◽  
Benjamin P Y Lau ◽  
David Lewis ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Green Algae ◽  
Solid Phase ◽  
Enzyme Linked Immunosorbent Assay ◽  
Blue Green Algae ◽  
Biochemical Assays ◽  
Liquid Chromatography Tandem Mass ◽  
Protein Phosphatase Inhibition ◽  
Phosphatase Assay

Abstract More than 100 samples of blue-green algae products (consisting of Aphanizomenon, Spirulina, and unidentified blue-green algae) in the form of pills, capsules, and powders were collected from retail outlets from across Canada. The samples were extracted with 75% methanol in water and centrifuged to remove solids. Aliquots of the extracts along with spiked blank sample extracts were sent to each participating laboratory and independently analyzed for microcystins by enzyme-linked immunosorbent assay (ELISA), protein phosphatase inhibition assay, and by liquid chromatography–tandem mass spectrometry (LC–MS/MS) after sample cleanup using C18 solid–phase extraction. The results obtained by ELISA and LC–MS/MS agreed very well over a concentration range of about 0.5–35 μg/g. The colorimetric phosphatase results generally agreed with the other 2 methods. While the 2 biochemical assays measured total microcystin content compared with a standard of microcystin LR, the LC–MS/MS method measured specific microcystins (LA, LR, RR, YR) using external standards of these for identification and quantitation. Microcystin LR was found in all positive samples by LC–MS/MS. Microcystin LA was the only other microcystin found in the samples analyzed. These 2 microcystins represent essentially all the microcystins that were present in the extracts. Otherwise, the LC–MS/MS results would have been significantly lower than the results of the biochemical assays had other unknown microcystins been present.

A Simple Method for the Determination of Carbaryl and 1-Naphthol in Fruit Juices by High-Performance Liquid Chromatography–Diode-Array Detection

2003 ◽  
Vol 66 (8) ◽  
pp. 1510-1513 ◽  
Author(s):  
GÜL ÖZHAN ◽  
SIBEL TOPUZ ◽  
BUKET ALPERTUNGA
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Fruit Juice ◽  
Degradation Products ◽  
Diode Array ◽  
Diode Array Detection ◽  
Simple Method ◽  
Array Detection

Carbaryl (Sevin) is a widely used N-methylcarbamate insecticide. In this study, a simple and sensitive reversed-phase, high-performance liquid chromatography method with diode-array detection has been developed for the determination of low levels of carbaryl and its degradation products 1-naphthol in several kinds of canned pure fruit juice. The compounds were captured on a C18 cartridge. The analytes were separated on a C18 column using a linear gradient of 40 to 60% acetonitrile in water in a period of 20 min. The extraction recoveries of carbaryl and 1-naphthol were in the range 93.5 to 98.0% and 90.7 to 96.0% for fruit juice, respectively. The detection limit was below 0.8 ng/ml and the calibration curves showed good linearity between 0.9998 and 0.9999.

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