8 research outputs found
Non-Targeted Analyses for Pesticides Using Deconvolution, Accurate Masses, and Databases – Screening and Confirmation
What Are the Essential Elements Needed for the Determination of Amino Acid Requirements in Humans?
The Pharmacokinetic Responses of Humans to 20 g of Alanyl-Glutamine Dipeptide Differ with the Dosing Protocol but Not with Gastric Acidity or in Patients with Acute Dengue Fever
Absorption, Distribution, and Milk Secretion of the Perfluoroalkyl Acids PFBS, PFHxS, PFOS, and PFOA by Dairy Cows Fed Naturally Contaminated Feed
The
transfer of the perfluoroalkyl acids (PFAAs) perfluorobutanesulfonate
(PFBS), perfluorohexanesulfonate (PFHxS), perfluorooctanesulfonate
(PFOS), and perfluorooctanoate (PFOA) from feed into tissue and milk
of dairy cows was investigated. Holstein cows (<i>n</i> =
6) were fed a PFAA-contaminated feed for 28 days. After the PFAA-feeding
period, three cows were slaughtered while the others were fed PFAA-free
feed for another 21 days (depuration period). For PFAA analysis plasma,
liver, kidney, and muscle tissue, urine, and milk were sampled and
analyzed using high-performance liquid chromatography (HPLC) with
tandem mass spectrometry (MS/MS). The average daily intake of dairy
cows was 3.4 ± 0.7, 4.6 ± 1.0, 7.6 ± 3.7 and 2.0 ±
1.2 μg/kg body weight (bw) for PFBS, PFHxS, PFOS, and PFOA,
respectively. Overall, PFBS, PFHxS, PFOS, and PFOA showed different
kinetics in dairy cows. In plasma, concentrations of PFBS (mean =
1.2 ± 0.8 μg/L) and PFOA (mean = 8.5 ± 5.7 μg/L)
were low, whereas PFHxS and PFOS continuously increased during the
PFAA-feeding period up to maximal concentrations of 419 ± 172
and 1903 ± 525 μg/L, respectively. PFOS in plasma remained
constantly high during the depuration period. PFOS levels were highest
in liver, followed by kidney, without significant differences between
feeding periods. The highest PFHxS levels were detected in liver and
kidney of cows slaughtered on day 29 (61 ± 24 and 98 ± 31
μg/kg wet weight (ww)). The lowest PFAA levels were detected
in muscle tissue. At the end of the feeding study, cumulative secretion
in milk was determined for PFOS (14 ± 3.6%) and PFHxS (2.5 ±
0.2%). The other two chemicals were barely secreted into milk: PFBS
(0.01 ± 0.02%) and PFOA (0.1 ± 0.06%). Overall, the kinetics
of PFOA were similar to those of PFBS and substantially differed from
those of PFHxS and PFOS. The very low concentration of PFBS in plasma
and milk, the relatively high urinary excretion, and only traces of
PFBS in liver (0.3 ± 0.3 μg/kg ww) and kidney (1.0 ±
0.3 μg/kg ww) support the conclusion that PFBS does not accumulate
in the body of dairy cows