Objective: To establish a high performance liquid chromatography method for the simultaneous determination of dimethyl oxalate (DMO) and diethyl oxalate (DEO) in workplace air. Methods: From January 2022 to January 2023, air samples were collected by silica gel tubes, desorbed by acetonitrile, separated by C18 chromatographic column, detected by photo-array detector, and retention time was used to characterize and peak area was used to quantify at 210 nm wavelength. Results: The linear relationships of DMO and DEO were good, r>0.999. The detection limits of DMO and DEO were 0.39 and 0.52 μg/ml, respectively. The quantitative limit was 1.28 μg/ml for DMO and 1.72 μg/ml for DEO. Average desorption efficiency for DMO was 82.40%-92.72%, and DEO was 94.13%-97.69%. The intra-assay precision of DMO was 1.87%-6.18%, and DEO was 2.25%-3.31%. Inter-assay precision of DMO was 3.29%-5.73%, and DEO was 1.38%-2.94%. Average sampling efficiencies were 100% for both DMO and DEO. Breakthrough capacity of DMO was 37.61 mg (200 mg solid adsorbent), DEO was >28.11 mg (200 mg solid adsorbent). Samples should be stored at 4 ℃ for at least 7 days. Conclusion: This method is easy to operate and has strong practicability. All indicators meet the requirements of the specification, and it is suitable for the simultaneous determination of DMO and DEO in the workplace air.
目的： 建立工作场所空气中草酸二甲酯（DMO）和草酸二乙酯（DEO）同时测定的高效液相色谱检测方法。 方法： 于2022年1月至2023年1月，空气样品采用硅胶管采集，乙腈洗脱解吸，经C18色谱柱分离，二极管阵列检测器检测，在210 nm波长下，以保留时间定性，峰面积定量。 结果： DMO和DEO测定方法的线性关系良好，r>0.999。DMO和DEO的方法检出限分别为0.39 μg/ml、0.52 μg/ml，方法定量下限分别为1.28 μg/ml、1.72 μg/ml。DMO和DEO的平均解吸效率分别为82.40%~92.72%、94.13%~97.69%，批内精密度分别为1.87%~6.18%、2.25%~3.31%，批间精密度分别为3.29%~5.73%、1.38%~2.94%。平均采样效率均为100%。DMO穿透容量为37.61 mg（200 mg固体吸附剂），DEO穿透容量为>28.11 mg（200 mg固体吸附剂）。在4 ℃条件下样品至少可以保存7 d。 结论： 该方法操作简便、实用性强，各项指标均满足规范要求，适用于工作场所空气中DMO和DEO的同时测定。.

Ni-modified Ag/SiO2 catalysts containing 0~3 wt.% Ni were obtained by impregnating Ni species onto Ag/SiO2 followed by calcination and reduction. The catalysts\' performance in the hydrogenation of dimethyl oxalate (DMO) to methyl glycolate (MG) was tested. Ag-0.5%Ni/SiO2 showed the highest catalytic activity among these catalysts and exhibited excellent catalytic stability. The effects of the Ni content on the structure and surface chemical states of catalysts were investigated by XRF, N2-sorption, XRD, TEM, EDX-mapping, FT-IR, H2-TPR, UV-vis, and XPS. The better catalytic activity and stability of Ni-modified Ag/SiO2 (versus Ag/SiO2) are ascribed to the improved dispersion of active Ag species as well as the higher resistance to the growth of Ag particles due to the presence of Ni species.

Objective: To investigate the clinical features, non-dialysis treatment and prognosis of acute renal injury caused by acute dimethyl oxalate (DMO) poisoning. Methods: Retrospective analysis was performed on the occupational data, clinical manifestation, laboratory examination, treatment methods and prognosis of 4 patients with acute DMO poisoning in July 2020. Results: A large number of white DMO crystals were observed in the workplace. Four patients had acute onset, presenting symptoms such as fatigue, abdominal distension, abdominal cramps and nocturia to varying degrees. Laboratory tests all showed acute kidney injury. Serum creatinine of patients at the onset were 119-835 μmol/L. Patients were given early treatment including rest, protection of renal function, hydration and alkalization of urine, Bailing capsule. Renal function of 4 patients returned to normal, and clinical prognosis was good. Conclusion: Acute DMO poisoning leads to acute renal injury, mainly with renal tubulointerstitial lesions such as hypogravity uria and aseptic leucuria. Active treatment in the early stage has a good short-term clinical prognosis.
目的： 探讨草酸二甲酯（DMO）中毒致急性肾损伤的临床表现及非透析治疗的方法、疗效及预后。 方法： 于2020年7月，对4例急性DMO中毒患者的职业资料、临床资料、实验室检查结果、治疗方法及病情转归等进行回顾性分析。 结果： 急性事故后现场调查可见工作场所内有大量白色DMO晶体。4例患者同时、短期内接触DMO后急性起病，出现不同程度的乏力、腹胀、腰腹部绞痛及夜尿增多等症状。实验室检查均显示急性肾损伤，起病时患者血肌酐119~835 μmol/L。早期予以休息、保护肾功能、水化碱化尿液等治疗，同时均给予百令胶囊治疗。4例患者症状缓解，肾功能完全恢复正常，临床预后良好。 结论： 急性DMO中毒导致急性肾损伤主要以低比重尿、无菌性白细胞尿等肾小管间质病变为主，早期积极治疗，临床短期预后较好。.

The support of MgO/γ-Al2O3 was initially prepared by a multiple impregnation method and Pd was placed on the surface of the MgO/γ-Al2O3 support via incipient wetness impregnation. Pd/MgO/γ-Al2O3 (Pd/MAO) catalysts were systematically characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), CO2-temperature-programmed desorption (TPD), transmission electron microscopy (TEM), CO-Fourier transform infrared (CO-FTIR), and X-ray photoelectron spectroscopy (XPS) and tested in the CO oxidative coupling to dimethyl oxalate (DMO) reaction. Compared to Pd/γ-Al2O3, the catalytic activities of the Pd/MAO catalysts improved significantly. The Pd/MAO catalyst with a 30% mass ratio of Mg to γ-Al2O3 delivers 3 times higher STY of DMO than that of Pd/γ-Al2O3. It has been demonstrated that MgO covered γ-Al2O3 layer-by-layer forming MAO supports, which can increase surface basicity and the interaction between Pd particles and the MAO supports. Moreover, the relationship between metal and support interaction and catalytic performance was discussed.

We report a green, template-free, and general one-pot method of endogenous growth of free-standing boehmite (AlOOH) nanosheets on a 3D-network 60 μm-Al-fiber felt through water-only hydrothermal oxidation reaction between Al metal and H2O (2Al + 4H2O → 2AlOOH + 3H2). Content and morphology of AlOOH nanosheets can be finely tuned by adjusting the hydrothermal oxidation time length and temperature. Palladium is highly dispersed on such AlOOH endogenously formed on Al-fiber felt via incipient wetness impregnation method and as-obtained Pd/AlOOH/Al-fiber catalysts are checked in the CO coupling to dimethyl oxalate (DMO) reaction. Interestingly, Pd dispersion is very sensitive to the thickness (26-68 nm) of AlOOH nanosheet, and therefore the conversion shows strong AlOOH-nanosheet-thickness dependence whereas the intrinsic activity (TOF) is AlOOH-nanosheet-thickness independence. The most promising structured catalyst is the one using a microfibrous-structured composite with the thinnest AlOOH nanosheet (26 nm) to support a small amount of Pd of only 0.26 wt %. This catalyst, with high thermal-conductivity and satisfying structural robustness, delivers 67% CO conversion and 96% DMO selectivity at 150 °C using a feed of CH3ONO/CO/N2 (1/1.4/7.6, vol) and a gas hourly space velocity of 3000 L kg-1 h-1, and particularly, is very stable for at least 150 h without deactivation sign.