ELISA and LC-MS/MS methods for determining cyanobacterial toxins in blue-green algae food supplements.
The use of natural products as a diet supplement is increasing worldwide but sometimes is not followed by adequate sanitary controls and analyses. Twenty samples of pills and capsules of lyophilised cyanobacteria (blue-green algae), commercialised in Italy as dietary supplements, were found positive at the Vibrio fischeri bioassay. Further analyses with ELISA and LC-MS/MS methods revealed the presence of four microcystin (MC) analogues, MC-LR, -YR, -LA, -RR and two demethylated forms of MC-RR. The highest total microcystin content was 4.5 and 1.4 microg g-1 in pills and capsules, respectively. The ELISA measurements, compared to the LC-MS/MS analyses, showed significantly lower concentrations of microcystins in pills, this confirming a possible ELISA underestimate of mixed microcystins, due to different sensitivities for some toxic analogues.
Bruno
M
M
Department of Environment and Primary Prevention, Istituto Superiore di Sanità, V.le Regina Elena 299, 00161, Rome, Italy. mbruno@iss.it
Fiori
M
M
Mattei
D
D
Melchiorre
S
S
Messineo
V
V
Volpi
F
F
Bogialli
S
S
Nazzari
M
M
D048908:Aliivibrio fischeri / Q000254:growth & development; D000818:Animals; D001427:Bacterial Toxins / Q000032:analysis*; D000458:Cyanobacteria / Q000737:chemistry*; D019587:Dietary Supplements / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D008401:Gas Chromatography-Mass Spectrometry; D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic / Q000032:analysis*
D001427:Bacterial Toxins; D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic; C065685:microcystin YR; C049865:cyanoginosin-LA; C063855:microcystin RR; C057862:cyanoginosin LR