EX-99. CERT

CERTIFICATION PURSUANT TO SECTION 302
OF THE SARBANES-OXLEY ACT OF 2002


I, Donald C. Burke, Chief Financial Officer of Merrill Lynch Total
Return Bond Fund, certify that:

1. I have reviewed this report on Form N-CSR of Merrill Lynch Total
Return Bond Fund and Master Total Return Bond Fund;

2. Based on my knowledge, this report does not contain any untrue
statement of a material fact or omit to state a material fact
necessary to make the statements made, in light of the circumstances
under which such statements were made, not misleading with respect
to the period covered by this report; and

3. Based on my knowledge, the financial statements, and other
financial information included in this report, fairly present in all
material respects the financial condition, results of operations,
changes in net assets, and cash flows (if the financial statements
are required to include a statement of cash flows) of the registrant
as of, and for, the periods presented in this report.


Date: February 18, 2003

              /s/ Donald C. Burke_____
              Donald C. Burke,
              Chief Financial Officer of
              Merrill Lynch Total Return Bond Fund



Exhibit 99.1

Certification Pursuant to Section 906 of the Sarbanes Oxley Act


I, Donald C. Burke, Chief Financial Officer of Merrill Lynch Total
Return Bond Fund (the "Fund"), certify that:

1. The N-CSR of the Fund (the "Report") fully complies with the
requirements of Section 13(a) or 15(d) of the Securities Exchange
Act of 1934; and

2. The information contained in the Report fairly presents, in all
material respects, the financial condition and results of operations
of the Fund.


Dated: February 18, 2003

              _/s/ Donald C. Burke____
              Donald C. Burke,
              Chief Financial Officer of
              Merrill Lynch Total Return Bond Fund



EX-99. CERT

CERTIFICATION PURSUANT TO SECTION 302
OF THE SARBANES-OXLEY ACT OF 2002


I, Terry K. Glenn, President of Merrill Lynch Total Return Bond
Fund, certify that:

1. I have reviewed this report on Form N-CSR of Merrill Lynch Total
Return Bond Fund and Master Total Return Bond Fund;

2. Based on my knowledge, this report does not contain any untrue
statement of a material fact or omit to state a material fact
necessary to make the statements made, in light of the circumstances
under which such statements were made, not misleading with respect
to the period covered by this report; and

3. Based on my knowledge, the financial statements, and other
financial information included in this report, fairly present in all
material respects the financial condition, results of operations,
changes in net assets, and cash flows (if the financial statements
are required to include a statement of cash flows) of the registrant
as of, and for, the periods presented in this report.


Date: February 18, 2003

              /s/ Terry K. Glenn___
              Terry K. Glenn,
              President of
              Merrill Lynch Total Return Bond Fund



Exhibit 99.1

Certification Pursuant to Section 906 of the Sarbanes Oxley Act

I, Terry K. Glenn, President of Merrill Lynch Total Return Bond Fund
(the "Fund"), certify that:

1. The N-CSR of the Fund (the "Report") fully complies with the
requirements of Section 13(a) or 15(d) of the Securities Exchange
Act of 1934; and

2. The information contained in the Report fairly presents, in all
material respects, the financial condition and results of operations
of the Fund.


Dated: February 18, 2003

              _/s/ Terry K. Glenn_____
              Terry K. Glenn,
              President of
              Merrill Lynch Total Return Bond Fund