We ran the instrument in multiple-response monitor mode and used the parent/daughter ion pairs of 867.5/849.5 (PbTx-1), 895.5/877.5 (PbTx-2), 897.5/725.4 (PbTx-3), 911.6/893.7 (PbTx-6), 899.6/863.9 (PbTx-9), and 657.4/273.2 (brevenal) to identify and quantify the PbTx components.
brevis cells and PbTxs. The daily mean total PbTx concentration and standard deviation in water samples ranged from 8 to 28 [micro]g/L from 7 to 11 September 2001.
The concentration of PbTx was too low to estimate particle size distribution for samples obtained during the nonexposed period of May 2002.
The dose rate of the deposited brevetoxins can be calculated from Table 3 for a breathing rate of 25 L/min and for a unit air concentration of 1 ng/[m.sup.3] of PbTx, as shown in Table 4.
Correlation of PbTx concentration with environmental factors.
All 39 personal samples taken during the sampling period of 3-7 May 2002 showed no detectable amount of PbTx. During the exposure period from 7 to 11 September 2001, a total of 39 personal samples (mean sampling time, 471 min) from both the Siesta and Lido beaches were analyzed.
We observed in the pilot studies that the water concentration of PbTx and onshore wind were important for red tide exposure.
The PbTx concentrations observed during the red tide episodes (including during previous studies) ranged from 1 to 80 ng/[m.sup.3].
Effects of novel antagonists of polyether brevetoxin (PbTx)-induced bronchoconstriction in allergic sheep.
Red tides in the Gulf of Mexico are commonly formed by the fish-killing dinoflagellate Karenia brevis, which produces nine potent polyether brevetoxins (PbTxs).
Seawater, urine, and rabbit serum used unmodified or diluted in buffer (PBS), and enriched with varying quantities of PbTxs before analyses, led to results more favorable than those obtained in pure buffer.
(40) has demonstrated that PbTxs are metabolized in shellfish and are implicated in shellfish toxicity.