To measure brevetoxins and minimize matrix effects
, we performed competitive experiments varying toxin concentration in the sample by dilution and comparing them with the results from matrix controls without toxin.
A Spearman rank correlation analysis was also used to determine if there was a possible difference in matrix effects
between the lyophilized materials used in 1996 and the liquid materials used in 1999.
The validation was carried out according to ISO 17025/FDA Guidance for Industry including selectivity, sensitivity, accuracy, recovery of PHT, reproducibility and suitability of the calibration curves, stability of PHT, and matrix effects
. The selectivity and sensitivity (absence of PHT) were verified by analyzing blank samples without PHT (extraction and matrix effects
For more complex specimens such as blood or plasma, matrix components can affect LC-MS ionization through ion suppression/enhancement or matrix effects
The matrix effects
for BP and BA were within 93 [+ or -] 14.29% to 99 [+ or -] 14.29%.
Extraction Recovery and Matrix Effect
. The extraction recoveries and matrix effects
of the method are summarized in Table 4.
Phospholipid-based matrix effects
in LC-MS bioanalysis.
One solution to overcoming matrix effects
is to have matrix-matched calibration solutions.
Posters: Lactobacilli identification by comparative sequence analyses of the tuf gene; Identification of lactic acid bacterial strains using molecular biology methods; Development of bacteriophage resistant starter cultures--genetic engineering vs classical methods; Texture Improvement of Fermented Dairy Products by enzymatic crosslinking with Transglutaminase; Matrix effects
on the kinetics of lactose hydrolysis in fermented and acidified milk products; The structure of casein in heated suspensions affects the acid gelation of milk; Relationship between instrumental and sensory measurements of consistency for fermented milk products; Sensory evaluation of yoghurt flavour; Sensory screening of exopolysaccharide producing yoghurt strains.
Some of the factors involved in among-manufacturer differences cannot be corrected easily, including differences in antiserum specificity and in matrix effects
. In the value transfers to RPSP-4 and RPPHS, however, only A1AT and Hp showed differences related to antisera, and those differences were minimal--in the range of [+ or -] 2% (unpublished data).
were tested by comparison of the peak areas of these new working solutions with those of the corresponding standard solutions diluted with methanol : 0.1% formic acid (1 : 1, v/v) at equivalent concentrations, and this peak area ratio is defined as the matrix effect
Addressing QC issues is critical to the identification of potential errors with patient results, including reagent matrix effects
as well as calibration misalignment of testing function.