GC-FPD phosphorus

[Earl]

I have recently aquired a used FPD for an HP 5890. I can't get the thing to detect low quantites. Below 5ppm is barely detected. I know that these things should be able to see down to 5ppb for organophosphate pesticides, as I have analysis from another lab, and their method.

I have the air and H2 flows set where the manual recomends, and I have the column into the detector as far as is recomended. I have confirmed that the flame lights easily, the phosphorus lens is pointing the correct direction, and the silica liner is in good shape.

Injection technique is splitless in a split/splitless port using a drilled uniliner without wool.

H2=100mL/min

air=100mL/min

column distance=155mm into detector

The photomultiplier is new and I set the voltage to the recomended setting.

Any suggestions are welcome.

[along]

Hi Earl,

What was your injection vol?
What type of column you are using?
If possible what what the OP pesticide you are looking for?
In what matrix?

Some OP pesticides tend to intereact with the active sites in the inlet or column.

[Earl]

injection volume is 3uL.
column is an EC-5 30m 0.53mm, have also used a new RTX-5 30m 0.32mm
for start up I have been looking at TPP.
For start up I have have the analyte in methanol

[along]

Hi,

What is the temp program that you are using now, If I remember correctly, TPP will come out late in OP pesticide residue analysis,
you can try to use isothermal method at 250 C, 1ml/min and see what is the Rt for this compound before youadjust your program accordingly


Hope this will help you

[Rich]

Does anyone know where I can get a used FPD detector? I have looked on LabX and ebay, but with little success. I am trying to add one on to a 5890, but do not want to pay the $10k Agilent wants for a new detector. I know someone named Earl on this thread recently found one.

Best regards,
Rich