On the basis of these assumptions and the knowledge that the ES-MS analyte originates from whole-blood hemoglobin that contains equal molar amounts of [alpha]- and non-[alpha]-chain species, it can be rigorously shown that
Nevertheless, the close correlation between the ES-MS results and the results obtained with other techniques imply that the assumptions are not widely divergent from reality.
This result indicates that using diluted whole blood without further purification to remove alkali metal salts is adequate for determining GHb by ES-MS.
The imprecision (CV) of the ES-MS measurements was determined by performing 10 replicate analyses on five separate samples.
A comparison of GHb determined by ES-MS with GHb determinations by other established methods is presented graphically in Fig.
9278) was comparable with that observed between ES-MS and HPLC affinity measurements (N.
An additional, incidental, result of the ES-MS quantification of GHb is the detection of hemoglobin variants.
This ES-MS method for the quantitative analysis of GHb is robust, simple, and rapid, with an intersample analysis time of <3 min.
The ES-MS results demonstrate that the degree of glycation of the [alpha]-chain is 0.
To test whether ES-MS analysis of the samples in acid solution could have caused some hydrolysis of the glucose adducts and hence led to lower GHb values in our results, we also analyzed two blood samples having ~14% GHb, as follows.
0% of total hemoglobin for an individual component)  would be too low to detect by ES-MS under the nonseparatory conditions used.