day-to-day coefficients variation ranged 8% 29% the of signal-to-noise 1.25pt ratio.25pt"> 3) was < 0.01

ng/mg for all compounds. Each test series included a drug-free hair sample as negative control.

Table 1  Ingredients of the cleansing product Ultra Clean    -- 

Components Ingredients

Shampoo (tube 1) 

(Aloe- rid shampoo)

             Sodium laureth sulfate, aloe vera, cocamido-propyl betaine, cocamid DEA, sodium PCA, tetrasodium EDTA, panthenol, citric acid,

                  sodium thiosulfate, methylparaben, DMDM hydantoin, sodium chloride, fragrance, coloring

Purifier (tube 2)

(Aloe-rid treatment)

                                      Aloe vera, propylene glycol, EDTA, potas-sium sorbate, methylparaben, carbomer-940, triethanolamine, coloring

Conditioner  Aloe vera, geranium maculatum, comfrey, (tube 3)grapefruit juice, hydrolized animal protein,

N-octadecanol, cetyl trimethyl ammoniumbromide, N-hexadecyl alcohol, methylparaben, propylparaben, fragrance, coloring)

hair was first wetted and half of the shampoo was applied for 3 min (step 1). Second the purifier was thoroughly distributed on the hair

and left to work for 3 min. Subsequently, the remainder of the shampoo was applied again for 3 min (step 3) before the condi-

tioner was used in the fourth step. After each step the hair was rinsed well with warm water. Shampoo, purifier and conditioner

were applied and distributed on the hair strands with a small brush. The hair samples were finally air dried.

Hair extraction

The proximal 4 cm of the hair strands were used for analysis. The hair segment was placed in a polypropylene vial and washed for

5 min each with water (5 ml), acetone (5 ml) and hexane (5 ml). After drying, the hair was cut into small pieces of about 1 mm and

40–80 mg was used for analysis. The hair was transferred to a polypropylene vial and 4 ml methanol and 100 µl of the internal

standard (IS) mixture (2 ng/µl of amphetamine-D11, MDA-D5,MDMA-D5, MDE-D6, cocaine-D3, morphine-D3, codeine-D3and

methadone-D9; 0.2 ng/µl of THC-D3) were added. The closed vial was sonicated for 4 h at 50 °C.

Table 2  Ions measured in

Purification

The methanol was evaporated and the residue was dissolved in 7 ml of phosphate buffer (0.1 M, pH 6) containing 400 mg of bovine

serum albumin. The mixture was then applied to a solid phase extraction column (Bakerbond SPE C18, 500 mg), which had been

conditioned by flushing with 2 ml of methanol and 2 ml of phosphate buffer (0.1 M, pH 6). The column was rinsed with 1 ml of

0.1 M acetic acid and dried for 10 min under vacuum. THC was first eluted with 3 ml dichloromethane/acetone (1:1; v/v), followed

by elution of amphetamines, opiates and cocaine with 3 ml dichloromethane/2-propanol/ammonia (40:10:1, v/v/v). Both ex-

tracts were evaporated under a slight stream of nitrogen at 30 °C.

Derivatization

µ

of dimethylsulfoxide and 60% aqueous tetrabutylammonium hydroxide solution (98:2, v/v) was added to the extract. Subse-

quently, 50 µl methyl iodide was added and the mixture was vortexed. After 5 min at room temperature,350 µl 0.1 N hydrochloric

acid was added. The methylated THC (THC-Me) was then extracted with 2 ×  1 ml isooctane. The organic layer was separated

and the solvent evaporated at 30 °C in a slight nitrogen stream. For GC/MS analysis the dry residue was dissolved in 50 µl of water-

free ethyl acetate.

Amphetamines and opiates were derivatized by adding 50µl of pentafluoropropionic anhydride (PFPA) to the extract and the mix-

ture was incubated at 70 °C for 30 min. The excess pentafluoropropionic anhydride was evaporated at room temperature in a slight

nitrogen stream. For GC/MS analysis the dry residue was dissolved in 50 µl of water-free ethyl acetate.

GC/MS analysis

For GC/MS analysis of amphetamines, opiates and cocaine a HP5 MS capillary column was used. The carrier gas was He (constant

flow: 1 mL/min), the injection volume 1 µl (splitless injection), the injector temperature 250 °C and the transfer line temperature

280 °C. The oven temperature program was 2 min isothermally at 60 °C, 40 °C/min to 170 °C, 8 °C/min to 270 °C and 13 min isother-

mally at 270 °C. EI ionization (70 eV) was used. The ions listed in Table 2 were measured in the selected ion monitoring (SIM) mode

(dwell time per ion: 30 ms). For analysis of THC the same GC/MS conditions were applied. The measured ions for THC-Me and

THC-D3-Me are also listed in Table 2.

Quantification and validation data

For quantification the peak areas of the ions specified as “target” (see Table 2) were used. Quantification was based on peak area ra-

tios relative to the respective internal standard (IS). A 5-point calibration curve was obtained by measuring spiked hair samples

(100 mg) containing 10, 50, 100, 200 and 400 ng of the analytes. The calibrations were linear in the range tested and the correlation

coefficients were > 0.99 for all compounds. The intra-assay precision was determined by analyzing five spiked hair samples (100 mg)

containing 200 ng of each drug in one series. The intra-assay coefficients of variation (CV) ranged from 7% to 26% (listed in Table 3).

Inter-assay precision data were obtained from analyses of the spiked hair samples (200 ng), performed on six different days. The

day-to-day coefficients of variation (CV) ranged from 8% to 29% and the limit of detection (signal-to-noise ratio = 3) was < 0.01

ng/mg for all compounds. Each test series included a drug-free hair sample as negative control.

Instrumentation and reagents

Instrumentation: Gas chromatograph HP 6890 with auto-sampler (Hewlett-Packard, Palo Alto, Calif.), mass-spectrometer HP 5973

(Hewlett-Packard), capillary column HP-5 MS (30 m, 0.25 mm internal diameter, 0.25µm film thickness; Hewlett-Packard). For soni-

cation the Elma T 460/H ultrasonic bath (Elma, Singen, Germany) was used, the 50 ml polypropylene vials with screw caps were pur-

chased from Falcon (Lincoln Park, N.J.). All solvents and reagents were analytical grade. Methanol, acetone, hexane, ethyl acetate,

dichloromethane, isooctane, ammonia, dimethylsulfoxide, tetrabutylammonium hydroxide, acetic acid and 2-propanol were pur-

chased from E. Merck (Darmstadt, Germany), methyl iodide, pentafluoropropionic anhydride and bovine serum albumin from

Sigma-Aldrich (Deisenhofen, Germany), solid phase extraction columns from Mallinckrodt Baker (Griesheim, Germany) and all

drug standard solutions as well as deuterated compounds from Radian (Austin, Tex.).

Table 4   Changes in THC con-        Without After Ultra Differ-

centration

treatment Clean ence

(ng/mg) (ng/mg) (%)

0.03 0.04 35

0.04 0.01 –78

0.57 0.28 –51

0.61 0.29 –51

Table 5   Changes in ampheta-         Without After Ultra Differ-

mine concentration

treatment Clean ence

(ng/mg) (ng/mg) (%)

0.11 0.05 –55

0.12 0.07 –44

0.13 0.15 16

0.34 0.17 –48

0.74 0.33 –56

0.94 0.39 –59

Results