District of Columbia election workers spent yesterday sorting through 4,600 challenged ballots in a painstakingly slow process aimed at allowing them to determine on Tuesday the definitive vote totals in the mayoral race and two close City Council seat contests.

About 15 election aides will have to work over the weekend researching registration records to check the voter eligibility of persons whose ballots, for any number of reasons, were not counted in the city election, according to Winfred Mundle, general counsel to the D.C. Board of Elections and Ethics.

By mid-afternoon yesterday, the aides were only "up to the Ms," said deputy elections administrator Delores Woods, who explained that the challenged ballots had to first be categorized into various "problem areas" before they could be cross-checked against the board's election registration list.

The challenged ballots and 1,000 absentee ballots were to be counted Tuesday, a week after the election and the mayoral and council winners certified a day or two later."

Most of yesterday was spent sorting through the challenged ballots and separating them into piles according to questions raised about party affiliation, name and address changes since registration, missing names on registration lists and failure to sign the challenged ballot envelope.

To insure voter confidentiality, those casting challenged ballots were asked to place them in unmarked envelopes. Those envelopes were then placed inside a second envelope that was supposed to be signed by the voter. Once voter eligibility has been determined, all the unsigned envelopes will be placed in an anonymous pile before being counted.

Today and Saturday elections aides are expected to pour over voter registration lists in an even more time-consuming effort to determine voting eligibility.

With City Councilman Marion Barry leading Council Chairman Sterling Tucker by barely 1,100 votes and Mayor Walter Washington trailing a close third, all three mayoral aspirants and their supporters are anxious to learn the final vote totals. None of the candidates expects the voting count to alter the outcome, but the waiting game has been tough on them and voters alike.

"I get embarrassed when we do something wrong, but I get heartsick when we don't and people blame us anyway," said Shari Kharasch, head of the elections board, who complained the board was being unfairly criticized for delays in counting the absentee and challenged ballots.

Kharasch explained that city election laws prohibit her office from counting absentee an challenged ballots until a full week after the election. This, she said, gives election aides time to establish voter eligibility and allows proper time for mailed absentee ballots - which can be postmarked as late as election day - to reach the board's office.

"In New York State the Supreme Court there ruled that you have to wait 12 days before you can count the absentee ballots," Karasch said. "Somehow people think we're taking a long time, but by law we have to wait."

Khrasch also reiterated previous statements that the board could work more efficiently if it had money in its budget to purchase sophisticated computer equipment for storing information and quicker vote counting.

Observers for the three mayoral candidates, as well as for Council candidates in Wards 5 and 6 where the absentee and challenged ballots could also alter the final outcome, were on hand yesterday and will continue to monitor the board's work until all the ballots hve been counted.