Pb {metRology}

Lead in wine

Description

A data frame containing reported results for lead (in mg/kg) from CCQM Key Comparison CCQM-K30.

Usage

	Pb

Format

A data frame containing 11 reported results with uncertainty data:

lab

Factor giving abbreviated laboratory identifier

value

The reported value for lead (mg/kg)

u

Standard uncertainty (mg/kg). The values in Pb were calculated from the reported expanded uncertainty U and coverage factor k using u=U/k.

k

Coverage factor. Conventionally, the coverage factor is set to a suitable quantile of Student's t based on the Welch-Satterthwaite effective degrees of freedom or simply set to 2 for approximately 95% confidence. In this data set, labs all quoted k for approximately 95% confidence.

U

Expanded uncertainty as reported by labs.

method

Factor indicating general measurement methodology:

IDMS

Isotope dilution mass spectrometry

ICP

Inductively coupled plasma spectrometry

GFAAS

Graphite furnace atomic absorbtion spectrometry

include

logical; Whether the reported result was included in the calculation of the Key Comparison Reference Value for the study.

Details

The study involved circulation of a homogeneous set of samples of wine for analysis for lead (Pb) content by a number of National Measurement Institutes.

The Key Comparison Reference Value, or assigned value for the lead content, was set at 2.99 mg/kg with expanded uncertainty 0.06 mg/kg.

Source

Hearn, R., Santamaria-Fernandez, R. and Sargent, M. (2008) Final report on key comparison CCQM-K30: Determination of lead in wine. Metrologia 45, 08001, 2008

References

See source.