CANDIDATE PREPARATION OF HUMAN HAIR REFERENCE MATERIAL FOR DETERMINATION TOTAL SELENIUM BY HYDRIDE GENERATION-QUARTZ FURNACE ATOMIC ABSORPTION SPECTROMETRY (HG-QFAAS)

• Main Author: (NIM: 20513081), HUMAIRA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/22462
• Institution: Institut Teknologi Bandung

Reference materials are widely used for several purposes such as validation of methods, instrument performance test, and evaluation of personel perfomance. Affordability reference materials specific to human hair matrix is still limited and relatively expensive. Trend analysis of biological specimens in human hair increases for its excellence capable of providing a profile of nutritional/diet status and exposure to xenobiotic in certain periods. Selenium (Se), one of the essential trace elements, has an important role in the metabolism of the human body mainly as a cofactor in a group of enzymes glutathione peroxidase (GPx), which acts as an antioxidant. This research studied the preparation of human hair material as a candidate reference material from the stage of selection and collection; pretreatment of washing procedure; homogenization; water content analysis; optimization of digestion; optimization of measurement conditions HG-QFAAS; stability testing of filtrate; and the assay of total Se by HG-QFAAS and NAA. Criteria of hair sampel that was chosen are human scalp hair, male sex, straight shape, black, no treatment history of rebonding and/or hair colouring. Pretreatment using detergent, acetone, and distilled water gradually. Homogenization was conducted by reducing the size, sieving, and mixing. Water content characteristics on candidate reference materials were (12.16 ± 1.73)%. Digestion was chosen for 0.5 to 1.0 gram mass sample using 20 mL HNO3 65% conducted by twice diluting digestion process. The optimum condition measurement of total Se by HG-QFAAS were 5 M HCl acid concentrations and reducing agent NaBH4 0.8% (w/v) in NaOH 1% (w/v). Stability test results of digestion filtrate conducted by measuring total Se on the first day until the ninth, and showed levels of total Se decreases over time. So the suitable package for candidate reference material as hair powder in glass vial packaging. Determination of total Se in the sample (n = 10) by HG-QFAAS and NAA respectively 2.7965 ± 1.8624 mg/kg and 1.8430 ± 0.4875 mg/kg (dry weight). Homogeneity test statistically by IBM SPSS Statistics 20 show homogeneity between the two groups of test methods (HG-QFAAS and NAA) in terms of the significant value of 0.176 (based on median) greater than the real level of 0.05.