As new chairman of the Senate Appropriations Committee, Mark O. Hatfield (R-Ore.) has dedicated himself to trying to keep legislative riders dealing with emotional issues such as abortion off his money bills.

For years Hatfield sat in the minority and watched appropriation bills slowed to the point on nearly closing down the government for lack of funds as members fought over whether federal funds should be spent on abortions, though this had nothing to do with the bill before them. Opponents seized on the money bills as their vehicle because liberals controlling the Judiciary committees bottled up constitutional amendments or legislation dealing with the subject.

But now the Senate is under Republican control, and conservative Strom Thurmond (R-S.C.) is in charge of the Senate Judiciary Committee. As a result, Hatfield has argued, the Senate can expect abortion legislation to come out of the Judiciary Committee, and should deal with the issue that way.

Hatfield's first payoff came this week when his committee met to act on a supplemental appropriation and rescission bill. The House had attached to it the usual riders forbidding use of federal money for abortions except in cases of danger to the expectant mother's life, and forbidding use of federal employes' health insurance to cover the cost of abortions.

Last year the committee approved anti-abortion language, but this time it went along with Hatfield. The House language was deleted without discussion and with only one audible "no" vote.

But Hatfield still has to get the bill past the full Senate, and Sen. Jeese A. Helms (R-N.C.), one of the most active opponents of abortion, has so far not agreed to go along with Hatfield. At a White House meeting on the subject recently Helms was "very guarded" on the subject, at Hatfield aide said.

And there is no way Hatfield can make his argument to the House, because there the Judiciary subcommittee that would handle an anti-abortion constitutional amendment is presided over by liberal Rep. Don Edwards (D-Calif.), who is dedicated to bottling up such legislation.

So the prospect is that the House will keep on loading up appropriation bills with anti-abortion, anti-affirmative action and similar riders. Hatfield will keep on trying to knock them out. And if he succeeds the issues will be fought out in conferences between the two bodies. Whether that saves any time in the appropriations process remains to be seen. Hatfield, incidentally, is against abortion.