Читать книгу X-Ray Fluorescence in Biological Sciences - Группа авторов - Страница 89

Analysis of body tissue (urine, blood, plasma, nail, or hair) for the determination of its composition has become the most powerful and ubiquitous tool for disease detection and control in recent years. If there any case of suspected exposure to different toxic element (Pb, Cd, and As), measurement of those element by using EDXRF is an excellent technique. Moreover, the presence of even some essential elements in more than the required quantities in any body tissue, like iron in urine, or manganese in blood, that can cause organ malfunction or pathogen‐initiated disease can also be detected by EDXRF. In addition, it may be said that XRF analysis using EDXRF spectrometers is a unique technique for the identification and quantification of elements in any substance, including body tissue. It is a fast, accurate technique for the determination of elements in even very small quantities of samples. it is notable that, for the rapid, nondestructive clinical analysis of trace element recently XOS, the Alzheimer's Center of Albany Medical Center, Albany, NY, USA in colaboration with the Wadsworth Center (New York State Department of Health, Albany, NY, USA) started to measure trace elements of interest; potential diagnosis and treatment of neurodegenerative diseases using an NIH‐supported study (NIH 2R44RR021797‐02) toward development of an HD XRF‐based analyzer [18].

Table 6.2 Precision and accuracy of the method.

Elements	Elemental concentration in Orchard leaf/NIST 1571 (mg/kg)	Mean	SD	Certified value Orchard leaf/NIST 1571	RE (%)	CV (%)
Exp‐1	Exp‐2
K	13 340	13 410	13 375	49.50	14 700	9.01	0.37
Ca	19 670	19 779	19 725	77.07	20 900	5.62	0.39
Mn	93.51	94.21	93.86	0.49	91	−3.14	0.53
Fe	270	298	284	19.80	300	5.33	6.97
Cu	11.97	10.49	11.23	1.05	12	6.42	9.32
Zn	26.99	24.97	25.98	1.43	25	−3.92	5.50
As	9.45	8.97	9.21	0.34	10	7.90	3.69
Rb	11.25	11.43	11.34	0.13	12	5.50	1.12
Sr	43.42	40.21	41.82	2.27	37	−13.01	5.43
Pb	46.98	48.60	47.79	1.15	45	−6.20	2.40

However, the present study ascertained,the precision and the accuracy of the obtained results were excellent (Tables 6.1 and 6.2). Total cost of analysis was also low as no chemicals were used to prepare the samples for analysis and makes it more affordable by the patients/customers. This method is very simple and handling the system is very easy. EDXRF has been demonstrated to be a very potential technique with high precision and accuracy with good sensitivity for the determination of As in hair tissue and Pb in whole blood samples at the clinical point of care. So, EDXRF is worthy of use in clinical diagnosis, particularly for the above mentioned cases.