Analysis/adsorption of anions at ppm/ppb levels quantitatively- diploma thesis ideas...

Thanks to Allan Adler, Bruce Hamilton,
[Only registered users see links. ](no constant name) Josh,
N:dlz,MM William Penrose and the rest for clarifying and providing
comprehensive discussions on the spectrophotometer problem.

I wanted some references or suggestions on another topic. In the last
year of M.Sc degree (technically equivalent to a undergraduate
degree), students opt for a thesis or a project, which is rather like
a diploma thesis in Germany. My supervisor has put forward two ideas
for the project( we have to keep in mind our limitations and lack of
chemical and apparatus) of studying the adsorption of polymers (eg
polyvinyl alcohol) on different adsorbents and study the isotherms.
Another idea is to use of a new "biomass" like algae, fungi, wood
shavings, or sawdust to adsorb (biosorp) different heavy metals (for a
interesting discussion on "What is a heavy metal" Hawkes, Stephen J.
What Is a "Heavy Metal"? J. Chem. Educ. 1997 74 1374, from aqueous
solutions. Though there is nothing new or innovative in it, what one
do is to find some new adsorbent of plant origin. The changes in
concentration of metals would be observed with ion-exchange resins or
AAS.

The third idea that I was thinking of is to study the adsorption of
anions by biomass found in polluted waters like nitrates, nitrites,
sulfides, phosphates from detergents, and many others, but the problem
according to my teacher is quantitative analysis of anions in "trace
levels". Perhaps very few (relatively inexpensive) instrumental
methods exist for ANIONS. The only one I know is ion-chromatography,
and spectrophotometric determination of nitrite/nitrate. We don't have
the ion-chromatography instrument!!

1.Are there any sensitive, relatively cheap chemical methods to
quatitatively determine common anions at ppm levels? Reference books
would be appreciated. "Spot Tests by Fritz Feigel is an excellent
book, but almost all tests are qualitative)

2. Could someone name sensitive spectrophotmetric methods (we have
UV-Visible Shimadzu-1601 spectrophotmeter) for the determination of
common anions like halides, nitrates, sulfates.
Perhpas I am asking too much of a favor, but any new ideas/ new topics
(not too advanced) would be welcomed.