Chromatography Forum

Hello

For years we have used Toxi-Lab A-Tubes for our urine GCMS general (basic) drug screen method. It was so fast and simple. Just fill an A-tube, mix, spin down, take off upper organic layer and dry down. Reconstitute and inject.

Now Agilent, who acquired Toxi-Lab from Variant, has decided to discontinue the product. What is most annoying is they only gave a month's notice. Anyway I'm wondering if anyone has alternative LLE method for general GCMS drug screening. I don't want to go to SPE because it is too time consuming, not suitable for STAT drug screening.

I can figure out what solvents they are using from the MSDS but no clue what the salt or buffer is.

TIA

Mike

LLE method for basic drugs in urine (AMP, OPI, BZD, TCA, COC, etc.)

I. Urine 1-5 mL into test tube
II. Add KOH solution to adjust pH 9-10 (KOH 5 M, 40 ul/mL), checked by pH paper
III. Add approx. 1 gram of sodium sulfate or sodium chloride, mix immediately using vortex
IV. Add 5 mL MTBE
V. Horizontal mix 10 min
VI. Centrifuge at 2600 rpm, 10 min
VII. Transfer the upper layer into new clean tube
VIII. Dry gentle under N2 at room temp.
IX. Reconstitute 50-100 microlitter with Ethyl acetate and GC or GC/MS analysis

You can use Borrate buffer pH 9 instead of step II.

Thanks I will give it a try.

Mike