Get-Counter not accepting array created from SQL

When I try and generate an array from a SQL output, although it's the same data type and content, perfmon doesn't accept these values, whereas it does for a manually created a list. So the first call for Get-Counter returns an error message as seen below, where as the second call with a manually created list works correctly. How do I resolve this? Get-Counter : Internal performance counter API call failed. Error: c0000bc4. At line:26 char:9 $SQLQueryGetCounters = " DECLARE @PerfmonCounterList VARCHAR(MAX) SELECT TOP 2 PerfmonCounter FROM Perfmon.PerfmonCounterList" $SQLQueryGetCounters = " DECLARE @PerfmonCounterList VARCHAR(MAX) SELECT top 2 ' "' +PerfmonCounter + '"' ItemValue FROM Perfmon.PerfmonCounterList " $Counters = @(Invoke-sqlcmd -ServerInstance Localhost -Database "DatabaseMonitoring" -Query $SQLQueryGetCounters )| select-object -expand ItemValue $List = [System.Collections.ArrayList]@() # New-Object System.Collections.Generic.List[System.Object] # [System.Collections.ArrayList]@() foreach ($Item in $Counters) { $List.Add($Item) } $List = $List.ToArray() Get-Counter -Counter $List $List = "\DATABASE(*)\DATABASE CACHE % HIT","\DATABASE(*)\DATABASE CACHE SIZE (MB)" Get-Counter -Counter $List