Sample Preparation Technology for Drug Detection of Criminal Investigation— Application of POWTEQ Micro Ball Mill GT300

 Hair poison analysis is reliable evidence in practice. Compared with urine, blood and other test samples, the most significant advantage of hair samples is to extend the retrospective period of drug abuse, which can dig out drug abuse information for a longer time, dozens of centimeters of hair can even reflect drug abuse information in several years.

Sample Preparation Technology of Hair Sample - Micro Grinding Extraction Method

 Micro-grinding extraction method is to grind the hair sample hair into fine powder by micro ball mill, effectively increasing the sample surface area so that the drug is fully released. At the same time, the inner cuticle of the hair will be destroyed after grinding, which is not only conducive to the effective penetration of the solvent into the hair but also has a significant effect on the drug extraction in the hair cortex and medulla. National Drug Laboratory conducted a set of experiments using the POWTEQ micro ball mill GT300, and the experimental results fully met the requirements of drug detection.

 To better demonstrate the application of micro ball mills in the field of drug detection, we carried out 50 sets of experiments with GT300 by 2 schemes.

1.Scheme 1: Samples are ground in 2ml vials.

(hair sample in 2ml vials before grinding)

Scheme 1: Test 1

Scheme 1: Test 2

Scheme 1: Test 3

2.Scheme 2:  Samples are ground in 5ml vials

(hair sample in 5ml vials before grinding)

Scheme 2: Test 1

Scheme 2: Test 2

Through experiments, we suggest that the following schemes can be selected for hair sample preparation for drug detection:

Scheme 1

1. Configuration: 2pcs. of 24-hole adapters,48 or even numbers less than 48 pcs. of2ml vials, 7mm balls zirconium oxide(or stainless steel) 2pcs for each vial;
2. Grinding speed:1800rpm;
3. Grinding time:120s-150s, the grinding results can fully meet the requirements of drug analysis;
4. If grinding time is set as 4mins,better fineness and evenness could be achieved. The sample is in the form of dry powder;
5. Grinding mode: continuous;6. Suggested sample batch capacity:10mg-55mg.
6. Suggested sample batch capacity:10mg-55mg.

Scheme 2:

1. Configuration:2pcs. of 6-hole adapters, 12 or even numbers less than 12pcs. of 5ml vials, 7mm stainless steel ball 2pcs. for each vial;2pcs. of 6-hole adapters, 12 or even numbers less than 12pcs. of 5ml vials, 5mm stainless steel ball 4pcs. for each vial;
2. Grinding speed: 1500rpm;
3. Grinding time: pause 10s for every 5 min grinding, total 10mins and 10s;
4. Grinding mode: Intermittent mode or continuous;
5. Suggested sample batch capacity: 200mg.

 The above 2 schemes have their advantages. For scheme 1, with the 2ml vials, the grinding time is short and a 24-hole adaptor is available, so 48 hair samples can be ground at the same time. For scheme 2, 5ml vials are more convenient to put sample hair compared with 2ml vials. Both schemes can meet the experimental requirements, customer can choose the more suitable scheme according to the situation.