公开(公告)号：US4897128A

公开(公告)日：1990-01-30

申请号：US178183

申请日：1988-04-06

申请人： Heinz Dosch ,  Dieter Hauffe ,  Horst Gehmecker

发明人： Heinz Dosch ,  Dieter Hauffe ,  Horst Gehmecker

IPC分类号： C23C22/12 ,  C23C22/77 ,  G01N27/26 ,  G01N31/00 ,  G01N31/16

CPC分类号： C23C22/77 ,  G01N31/164

摘要： Described is a process for determining the zinc content of an acid aqueous phosphating bath. A bath sample is titrated at a pH value between 1.2 and 1.7 in the presence of ethylenediaminetetraacetic acid, hexamethylenetetramine and alkalihexacyanoferrate (III) with an alkalihexacyanoferrate(II) until the potential at an oxidation-reduction electrode immersed into the bath sample reaches an inflection point.Any content of nitrite and/or iron(II) ions must be removed by an addition of nitrite-destroying substances and by an oxidation to iron(III) ions at a pH value above 8.The process is particularly suitable for determining the zinc concentration of phosphating baths which contain 0.4 to 2.0 g/l Zn. The presence in phosphating baths of additional cations such as manganese and/or calcium and/or nickel and/or magnesium does not interfere with the process. The analysis can be automatic and may directly be used to control a metering device for supplying make-up concentrates to the phosphating bath.

摘要翻译： 描述了确定酸性磷酸氢盐浴的锌含量的方法。 在乙二胺四乙酸六亚甲基四胺和碱金属氰化铁酸盐（III）与碱金属氰化铁酸盐（II）的存在下，在1.2至1.7的pH值下滴定浴样品，直到浸入浴液样品中的氧化还原电极的电位达到拐点 。 亚硝酸根和/或铁（II）离子的任何含量必须通过加入亚硝酸盐破坏物质和通过氧化成铁（III）离子在pH值高于8处去除。该方法特别适用于测定锌浓度 的含有0.4〜2.0g / l Zn的磷化浴。 存在附加阳离子如锰和/或钙和/或镍和/或镁的磷化浴不会妨碍该方法。 分析可以是自动的，并且可以直接用于控制用于向磷化浴提供补充浓缩物的计量装置。