Quantification of Polychlorinated Biphenyls and Polybrominated Diphenyl Ethers in Commercial Cows’ Milk from California by Gas Chromatography–Triple Quadruple Mass Spectrometry

<div><p>We determined 12 polybrominated diphenyl ethers (PBDEs) and 19 polychlorinated biphenyls (PCBs) congeners in eight different brands of commercial whole milk (WM) and fat free milk (FFM) produced and distributed in California. Congeners were extracted using a modified quick, easy, cheap, effective, rugged and safe (QuEChERS) method, purified by gel permeation chromatography, and quantified using gas chromatography-triple quadruple mass spectrometry. PBDEs and PCBs were detected in all FFM and WM samples. The most prevalent PBDE congeners in WM were BDE-47 (geometric mean: 18.0 pg/mL, 0.51 ng/g lipid), BDE-99 (geometric mean: 9.9 pg/mL, 0.28 ng/g lipid), and BDE-49 (geometric mean: 6.0 pg/mL, 0.17 ng/g lipid). The dominant PCB congeners in WM were PCB-101(geometric mean: 23.6 pg/mL, 0.67 ng/g lipid), PCB-118 (geometric mean: 25.2 pg/mL, 0.72 ng/g lipid), and PCB-138 (geometric mean: 25.3 pg/mL, 0.72 ng/g lipid). The sum of all 19 PCB congeners in FFM and WM were several orders of magnitude below the U.S. FDA tolerance. The sum of PBDEs in milk samples suggest close proximity to industrial emissions, and confirm previous findings of elevated PBDE levels in California compared to other regions in the United States.</p></div

The limit of detection (LOD), limit of quantification (LOQ), detection frequency (DF) and geometric mean (GM), geometric standard deviation (GSD) and median of analyzed PBDEs in eight brands of bovine milk samples analyzed in triplicate.

<p>The limit of detection (LOD), limit of quantification (LOQ), detection frequency (DF) and geometric mean (GM), geometric standard deviation (GSD) and median of analyzed PBDEs in eight brands of bovine milk samples analyzed in triplicate.</p

The geometric mean (GM), geometric standard deviation (GSD) and median of analyzed PCBs and PBDE concentrations corrected by milk fat (ng/g lipid) in eight brands of bovine milk samples analyzed in triplicate.

<p>The geometric mean (GM), geometric standard deviation (GSD) and median of analyzed PCBs and PBDE concentrations corrected by milk fat (ng/g lipid) in eight brands of bovine milk samples analyzed in triplicate.</p

The concentrations of ∑PBDEs and ∑PCBs with the relative amount of chlorination and bromination.

<p>(A) ∑PBDEs (Tri: BDE-17 and -28, Tetra: BDE-47, -49 and -66; Penta: BDE-85, -95, -99 and -100; Hexa: BDE-153 and -154; Hepta: BDE-183). (B) ∑PCBs (Di: PCB-11; Tetra: PCB-77; Penta: PCB-84, -91, -95, -101 and -118; Hexa: PCB-131, -132, -135, -136, -138, -149 and -153; Hepta: PCB-174, -175, -176 and -180; Octa: PCB-196). Number 1 to 8 represent eight different brands of commercial milk. ‘C’ indicates conventional milk, while ‘O’ indicates organic milk. Data shown are the geometric mean (pg/mL).</p

The concentrations of ∑PBDEs and ∑PCBs in fat free milk and whole milk.

<p>Data shown are the geometric mean (pg/mL) with geometric standard deviation, of eight brands of milk samples analyzed in triplicate (fat free milk n = 24, whole milk n = 23).</p

The limit of detection (LOD), limit of quantification (LOQ), detection frequency (DF) and geometric mean (GM), geometric standard deviation (GSD) and median concentrations (pg/mL) of analyzed PCBs in eight brands of bovine milk samples analyzed in triplicate.

<p>The limit of detection (LOD), limit of quantification (LOQ), detection frequency (DF) and geometric mean (GM), geometric standard deviation (GSD) and median concentrations (pg/mL) of analyzed PCBs in eight brands of bovine milk samples analyzed in triplicate.</p

Flexible Cathode Enabled by Ultralong Na₂V₆O₁₆·3H₂O Nanowire for High Rate and Durable Aqueous Zinc Ion Batteries

Aqueous zinc ion batteries (ZIBs) have garnered increasing attention owing to their safe aqueous electrolyte and suitable energy and power density. However, the development of appropriate cathode materials for commercialization remains a challenge. Herein, we report a flexible binder-free film cathode composed of hydrated sodium vanadate nanowires and carbon nanotubes (NaVO/CNT). The as-prepared film cathode exhibits a remarkably high rate performance, delivering a capacity of 402 mAh g–1 at 0.1 A g–1 and 284 mAh g–1 at 6 A g–1. Furthermore, excellent long-term stability is achieved with a retention rate of 90.04% after 5000 cycles at 4 A g–1. This cathode demonstrates outstanding performance compared with those of other sodium vanadate-based cathodes in aqueous ZIBs. Additionally, the co(de)insertion mechanism of H+ and Zn2+ ions is verified

Conserved amino acid motifs in the NBS domain of the <i>PgNBS</i> gene proteins identified using the MEME 4.0 software.

<p>(A) Sequence logo of seven prominent conserved motifs in the NBS domain of the CC type. (B) Sequence logo of seven prominent conserved motifs in the NBS domain of the TIR type. (C) Sequence logo of six prominent conserved motifs in the NBS domain of the RPW8 type.</p

Expression heatmap of the <i>PgNBS</i> gene transcripts in the roots of different year-old plants.

<p>One hundred fifty-two of the 412 NBS gene transcripts were found to express in the roots of these different year-old plants and therefore, used for the heatmap construction.</p

Conserved amino acid motifs in the N terminal region of the <i>PgNBS</i> gene proteins identified using the MEME 4.0 software.

<p>(A) Sequence logo of prominent conserved motifs in the N terminal region of the TIR type. (B) Sequence logo of prominent conserved motifs in the N terminal region of the RPW8 type.</p