Quality control samples for routine use in water laboratories

Summary Quality management systems in water laboratories have steadily improved during the past years, and the use of quality control samples is becoming routine. A selection of quality control samples has been designed and prepared by the Danish reference laboratory for water analysis. The samples cover 38 parameters at up to three concentration levels that are typical for environmental water. The samples have been produced in quantities that enable frequent use. Some samples are distributed together with preconstructed control charts for laboratory staff with limited knowledge of control chart statistics. Other users apply a Quality 4.0 computer programme for administration and statistical handling of quality control data with construction of control charts.