树木样品中全磷的流动注射分析——钒钼黄显色法

本文用流动注射分析法(FIA),以钒钼酸盐试剂为载流,成功地测定了树木样品中磷的含量。此分析方法简单,分析速度达120样/小时,在30℃时连续进样的相对标准偏差RSD％<0.5,样品回收率为99.7±20％,分析结果与经典的比色分析结果梧近。FIA钒钼黄法流路简单,只用一种试剂为载流,记忆效应小,在基线漂移方面也比钼兰法优越,最适合大批树木样品中磷含量的测定。

发酵液中植酸酶活性测定方法的研究

以钒钼法对发酵液中植酸酶活性进行了测定,并对影响酶活性测定结果的因素进行了研究。实验结果表明,钒钼法测磷的灵敏度和线性范围分别为0.025mmol/L和0.025mmol/L^0.60mmol/L;为减小植酸酶活性的测定误差,结果测定必须在颜色反应结束后的4h以内完成。研究中同时发现,发酵液含有的无机磷远远大于酶活测定产生的无机磷含量,直接用发酵液测得的植酸酶酶活是不可靠的。通过对透析2h的发酵液进行植酸酶酶活的测定,实验结果的最大相对偏差仅为7.1%。

对发酵生产植酸酶过程中植酸酶活性测定方法的初步探讨

以钼蓝法、钼钒法 ,对标准磷溶液和发酵液中的植酸酶酶活进行了测定 ,并研究了影响测定结果的各个因素。结果表明 ,钼蓝法、钼钒法均可用于植酸酶酶活的测定 ,且同样有效 ,但钼钒法相对快速、简便。研究中同时发现 ,发酵过程中发酵液含有的无机磷远远大于酶活测定产生的无机磷含量 ,直接用发酵液测得的植酸酶酶活是不可靠的。文中采用发酵液透析后测定酶活 。

Characterization of V_2O_5/MoO_3 composite photocatalysts prepared via electrospinning and their photodegradation activity for dimethyl phthalate

Vanadium pentoxide（V2O5）/molybdenum trioxide（MoO 3） composites with different molar ratios of vanadium（V） to molybdenum（Mo） were synthesized via a simple electrospinning technique. The photocatalytic activity of the composites were evaluated by their ability to photodegrade methylene blue and dimethyl phthalate（DMP） under visible-light irradiation. Compared with pure V2O5 and MoO 3,the V2O5/MoO 3 composites showed enhanced visible-light photocatalytic activity because of a V 3d impurity energy level and the formation of heterostructures at the interface between V2O5 and MoO 3. The optimal molar ratio of V to Mo in the V2O5/MoO 3 composites was found to be around 1/2. Furthermore,high-performance liquid chromatographic monitoring revealed that phthalic acid was the main intermediate in the photocatalytic degradation process of DMP.