Yan-Qing Wang,Wen-Qing Yan,Li-Xue Nie,Ping-Ping Luan,Chao-Qun Li
C 20 H 22 Cu 3 N 8 O 10 , monoclinic, C 2/ c (no. 15), a = 12.0766(11) Å, b = 16.2778(14) Å, c = 14.7605(13) Å, β = 97.8580(10) ∘ , V = 2874.4(4) Å 3 , Z = 4, R
gt ( F ) = 0.0420, wR
ref ( F
2 ) = 0.0988, T = 298.15 K.
Two nanosized titanium-oxide clusters (TOCs), Ti12(μ2-O)14(μ3-O)4PA16 (1; PA = 2-picolinate) and Ti12(μ2-O)18PA18 (2) were synthesized by using 2-picolinic acid and Ti(OiPr)4 in one-pot reactions. Their structures were determined using single-crystal X-ray diffractometry. Although both have the same core composition of Ti12O18, 1 exhibited superior H2 evolution activity of up to 180 μmol h−1 g−1, which is nearly eight times faster than 2. Mechanism studies revealed that 1 could induce the assembly of 2.3 nm PtNPs into 10–30 nm supra-nanoparticle structures, which contributed to the increased H2 evolution rate.
Dietary intake is a major pathway of human exposure to perfluorinated compounds (PFCs). Livestock and poultry meats (chicken, beef, mutton) account for a significant proportion of dietary consumption in China, and thus it is crucial to investigate the levels and composition profiles of PFCs in consumer meats to assess and mitigate potential health risks. However, rapid and simple analytical methods for such investigations are lacking. This study addresses this shortcoming by developing a rapid filtration clean-up method using carboxylic multi-walled carbon nanotubes (CMWCNTs) for the detection of 14 PFCs. Good linearities (R 2 > 0.99) were obtained for all 14 PFCs in chicken, beef, and mutton. Recoveries ranged from 65 to 145% (except perfluorotetradecanoic acid, PFTeDA) with relative standard deviations (RSDs) lower than 16%. Method limits of detection (LODs) were between 0.12 and 0.83 ng g −1 d.w. Subsequently, this method was applied for the analysis of 46 livestock and poultry meat samples collected from markets in Shanghai. PFCs were detected in all samples with total concentrations of 1.61–4.27 ng g −1 wet weight (w.w) in chicken, 1.51–5.56 ng g −1 w.w in beef and 1.61–8.15 ng g −1 w.w in mutton. Perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA) were the predominant compounds in these samples and accounted for over 92% of ΣPFCs. For regulated compounds such as PFOA, risk quotients (RQs) were determined to be much lower than 1. This suggests that chicken, beef, and mutton from Shanghai market pose very low PFC exposure risk to residents. However, high detection frequency of the unregulated PFBA demands further investigation of short-chain PFCs in consumer meats.
危险品化学品经营许可证（带存储）