Alimenter, trier et éliminer doublons dans des combobox

Private Sub UserForm_Initialize()
  Set f = Sheets("BD")
  Set champ1 = f.Range("a2:a" & f.[A65000].End(xlUp).Row)
  Set champ2 = f.Range("b2:b" & f.[b65000].End(xlUp).Row)
  Set d1 = CreateObject("Scripting.Dictionary")
  a = champ1.Value
  b = champ2.Value
  For Each c In a
    d1(Split(c, "@")(1)) = ""
  Next c
  For Each c In b
    d1(Split(c, "@")(1)) = ""
  Next c
  d = d1.keys
  Call Tri(d, LBound(d), UBound(d))
  Me.ComboBox1.List = d
  Me.combobox2.List = d
End Sub

Sub Tri(a, gauc, droi) ' Quick sort
  ref = a((gauc + droi) \ 2)
  g = gauc: d = droi
  Do
    Do While a(g) < ref: g = g + 1: Loop
    Do While ref < a(d): d = d - 1: Loop
    If g <= d Then
       temp = a(g): a(g) = a(d): a(d) = temp
       g = g + 1: d = d - 1
    End If
  Loop While g <= d
  If g < droi Then Call Tri(a, g, droi)
  If gauc < d Then Call Tri(a, gauc, d)
End Sub