Development of drug quantification method in blood by a simple visible spectrometer

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K09299
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 55060:Emergency medicine-related
• Research Institution: National Research Institute of Police Science
• Principal Investigator: Tsujikawa Kenji 科学警察研究所, 附属鑑定所, 鑑定官 (50356193)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: カフェイン / 検査キット / 血中濃度 / 判定

Outline of Final Research Achievements

We developed a simple estimation method using a point-of-care test kit for urinary caffeine (CAF). CAF-spiked human serum was diluted with PBS and applied to the kit. After 5 min incubation, the kit was scanned by a scanner and the membrane image was processed with ImageJ.
When the 20-fold diluted serum was applied, serum samples with initial CAF concentration 25 and 50 ug/mL were CAF-negative and -positive, respectively. When the 100-fold diluted serum was applied, none of the CAF-spiked serum samples gave positive. Therefore, we proposed the following test procedure: i) 20-fold diluted serum was initially tested and ii) 100-fold diluted serum was additionally tested when the initial result was CAF positive. Using this procedure, CAF concentration is classified into 3 levels: <25, 25 to 100, and >100 ug/mL. The test procedure was validated using postmortem heart blood from two cases of fatal CAF intoxication (CAF concentration: 276 and 175 ug/mL) and two cases of other intoxication.

Free Research Field

法中毒学

Academic Significance and Societal Importance of the Research Achievements

カフェイン中毒は増加が著しく、また、時に致死的な中毒である。一方で、血液浄化法により血中からカフェインを除去することで、血中カフェイン濃度が致死濃度域であっても十分に救命可能である。本研究成果は、血液浄化法を適応するかどうかを判断する上で有用な血中カフェイン濃度の判定法となることが期待される。