European collaborative study on luteinizing hormone assay: 2. Discrepancy among assay kits is related to variation both in standard curve calibration and epitope specificity of kit monoclonal antibodies

1994 ◽  
Vol 17 (6) ◽  
pp. 407-416 ◽  
Author(s):  
S. Costagliola ◽  
P. Niccoli ◽  
M. Florentino ◽  
Pierre Carayon ◽  
P. Beck-Peccoz ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Luteinizing Hormone ◽  
Collaborative Study ◽  
Standard Curve ◽  
Epitope Specificity ◽  
European Collaborative Study ◽  
Hormone Assay

Collaborative Study Using Atomic Absorption Spectrophotometry for the Determination of Copper in Alcoholic Products

1967 ◽  
Vol 50 (2) ◽  
pp. 338-339
Author(s):  
Duane H Strunk ◽  
A A Andreasen
Keyword(s):  
Atomic Absorption ◽  
Spectrophotometric Method ◽  
Collaborative Study ◽  
Atomic Absorption Spectrophotometry ◽  
Good Precision ◽  
Absorption Method ◽  
Standard Curve ◽  
Absorption Spectrophotometry ◽  
Determination Of Copper

Abstract A collaborative study was conducted on the 'atomic absorption spectrophotometric method for measuring the concentration of copper in alcoholic products. In this method, the samples are aspirated directly into the burner of the instrument, and the absorhance values are converted to ppm copper by reference to a standard curve. Data show good precision and are comparable to those obtained by the ZDBT method. It is recommended that the atomic absorption method be adopted as official, first action.

Poor Interoperability of the Adams-Harbertson Method for Analysis of Anthocyanins: Comparison with AOAC pH Differential Method

2013 ◽  
Vol 96 (1) ◽  
pp. 86-90 ◽  
Author(s):  
Larry M Brooks ◽  
Benjamin J Kuhlman Kuhlman ◽  
Doug W McKesson ◽  
Leo McCloskey
Keyword(s):  
Ad Hoc ◽  
A Priori ◽  
Collaborative Study ◽  
Maximum Error ◽  
Differential Method ◽  
Pinot Noir ◽  
Cabernet Sauvignon ◽  
Official Method ◽  
Standard Curve ◽  
Aoac Official

Abstract The poor interoperability of anthocyanin glycosides measurements by two pH differential methods is documented. Adams-Harbertson, which was proposed for commercial winemaking, was compared to AOAC Official MethodSM 2005.02 for wine. California bottled wines (Pinot Noir, Merlot, and Cabernet Sauvignon) were assayed in a collaborative study (n = 105), which found mean precision of Adams- Harbertson winery versus reference measurements to be 77 ± 20%. Maximum error is expected to be 48% for Pinot Noir, 42% for Merlot, and 34% for Cabernet Sauvignon from reproducibility RSD. Range of measurements was actually 30 to 91% for Pinot Noir. An interoperability study (n = 30) found Adams-Harbertson produces measurements that are nominally 150% of the AOAC pH differential method. Large analytical chemistry differences are: AOAC method uses Beer-Lambert equation and measures absorbance at pH 1.0 and 4.5, proposed a priori by Flueki and Francis; whereas Adams-Harbertson uses “universal” standard curve and measures absorbance ad hoc at pH 1.8 and 4.9 to reduce the effects of so-called co-pigmentation. Errors relative to AOAC are produced by Adams-Harbertson standard curve over Beer-Lambert and pH 1.8 over pH 1.0. The study recommends using AOAC Official Method 2005.02 for analysis of wine anthocyanin glycosides.

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