  We have used ATLAS12 to generate hydrogen-deficient stellar atmospheres to
allow us to construct synthetic spectra to explore the possibility that the
donor stars in some cataclysmic variables (CVs) are hydrogen deficient. We find
that four systems, AE Aqr, DX And, EY Cyg, and QZ Ser have significant hydrogen
deficits. We confirm that carbon and magnesium deficits, and sodium
enhancements, are common among CV donor stars. The three Z Cam systems we
observed are found to have solar metallicities and no abundance anomalies. Two
of these objects, Z Cam and AH Her, have M-type donor stars; much cooler than
expected given their long orbital periods. By using the combination of
equivalent width measurements and light curve modeling, we have developed the
ability to account for contamination of the donor star spectra by other
luminosity sources in the binary. This enables more realistic assessments of
secondary star metallicities. We find that the use of equivalent width
measurements should allow for robust metallicities and abundance anomalies to
be determined for CVs with M-type donor stars.
