分光光度法测定环氧琥珀酸合成体系中的酒石酸

基于酒石酸与偏钒酸铵的特异显色反应,建立了一种分光光度计法测定环氧琥珀酸合成体系中酒石酸含量的方法。研究了显色剂用量和硫酸溶液用量的影响,并考察了空白样和试样的稳定性;对体系中其他组分的干扰以及适用的质量浓度范围进行了初步探讨,并检验了该方法的精密度和准确度。该方法相对标准偏差小于1%,标准误差低于3%。     

DETERMINATION OF SOLUBLE NITROGEN BY SPECTROPHOTOMETRY

A simple spectrophotometric method for the determination of nitrogen in unhopped wort has been tested by the EBC Analysis Committee and accepted for inclusion in Analytica-EBC. The spectrophotometric method is intended as a quick method for routine quality control. It is emphasized that the procedure has to be followed in detail and that the precautions stated under Notes on Procedure are most important. The average precision values obtained for the range 600 to 850 mg/litre were r₉₅=30 and R₉₅ = 104.     

空气-乙炔火焰原子吸收分光光度法测定铅精矿中微量氧化钙

利用空气 -乙炔火焰原子吸收分光光度法研究了铅精矿中氧化钙的测定 ,采用基体匹配法消除基体铅的干扰 ,选择氯化锶与EDTA作释放剂 ,建立了铅精矿中微量氧化钙的测定方法。该法操作简便 ,精密度和准确度较好 ,方法相对标准偏差为 3.0 4% ,加标回收率在 99%～ 10 1%之间     

十二烷基磺酸钠存在下DBC-偶氮氯膦分光光度法测定化学试剂中的痕量铝

研究在pH 4.3 HAc-NaAc缓冲介质中,Al(Ⅲ)一（DBC-偶氮氯膦）一十二烷基磺酸钠( SDS)体系光度性质。研究结果表明：该显色体系的λmax= 622 nm,ε622nm=1.41×104 L·mol-1.cm-1,络合物组成比为Al(Ⅲ)：(DBC-CPA)=1:1,铝量在0.20～1.20 mg.L-1范围内遵守比耳定律。方法已满意地用于碳酸氢钠、氢氧化钠中痕量铝的测定。     

Lead and cadmium in tissues from horse, sheep, lamb and reindeer in Sweden

 Levels of lead and cadmium were determined in tissues of muscle, liver and kidney from horse, lamb, sheep and reindeer in Sweden during the years 1994–1997. Mean levels of lead in muscle, liver and kidney from horse were <0.002, 0.13 and 0.047, from lamb <0.002, 0.031 and 0.053, from sheep <0.002, not analysed and 0.046, and from reindeer 0.003, 0.13 and 0.13 mg/fresh weight, respectively. The mean levels of cadmium in muscle, liver and kidney from horse were 0.042, 2.5 and 18, from lamb 0.0019, 0.031 and 0.12, from sheep 0.0034, not analysed and 1.0, and from reindeer 0.003, 0.60 and 2.7 mg/fresh weight, respectively. Comparisons with literature data were attempted. In some cases the results could differ by several orders of magnitude. It cannot be ruled out that some of the differences between studies might be due to analytical differences, making comparisons very difficult. Received: 2 June 1998     

用DSPCF分光光度法测定钯

在室温下以硝酸为介质,钯与DSPCF形成有色络合物,其表观摩尔吸光系数ε_(520)=1.2×10~4,络合物组成为Pd(Ⅱ):DSPCF=1:2。其特点是在室温下发生显色反应,当加入HNO_3使介质达1.75N时,只有Pd(Ⅱ)—DSPCF红色络合物不褪色,可用于铂钯二次精矿等的测定。     

耐硫变换催化剂中钼含量的测定

用分光光度法,测定耐硫变换催化剂中三氧化钼的含量,与原子吸收法测定结果进行对比,其方法简便、仪器简单、准确度高,结果满意。     

树脂悬浮光度法测定微量银

在ｐＨ６．９的缓冲溶液中，银与硫代米Ｃｈｉ酮（ＴＭＫ）形成的螯合物在树脂甘油相中悬浮富集，用光度法测定银在波长４６１ｎｍ处有最大吸收，银在０～６μｇ／１０ｍＬ范围内遵守比尔定律，可用于样品中微量银的测定。     

多波长光谱法测定红糖中总铁和亚铁的含量

国家标准采用原子吸收光谱法测定食品中铁含量,其前处理需要灰化等步骤,操作繁琐,耗时耗能,测的为总铁的含量。本文建立了一种三波长邻菲罗啉显色法测定红糖总铁和亚铁含量的方法,先将红糖直接溶解成一定浓度的红糖溶液,然后按照邻菲罗啉显色法并基于423、510和700 nm波长处的吸光度测出总铁的含量,并进行了红糖中总铁含量的回收率试验。红糖溶液在不添加还原剂的情况下按照相同方法测出亚铁的含量。该方法能够有效扣除了红糖中多种色素以及基线漂移对结果的影响,结果发现试验的红糖样品,其中总铁的含量为(13.65±0.29)mg/kg,亚铁含量为(13.29±0.18)mg/kg,以二价铁为主,占总铁含量98%以上;红糖中总铁含量的回收率约103%。本方法避免了灰化前处理时的繁琐,测定较简便,结果准确,适用于生产企业使用。     

紫外分光光度法测定水体总氮的影响因素

本文就紫外分光光度法在测定水体总氮中易影响测定工作的几个方面做了阐述,并提出了改进意见