Thẩm định quy trình phân tích Arsenic vô cơ và Arsenic hữu cơ trong nước mắm bằng phương pháp quang phổ hốp thu nguyên tử với kỹ thuật tạo hydride

T p chí Khoa h c và Công ngh , S 50, 2021

© 2021 i h c Công nghi p thành ph H Chí Minh

TH NH QUY TRÌNH PHÂN TÍCH ARSENIC IC

H C M M B NG

H P THU NGUYÊN T V I K THU T T O HYDRIDE

C t Chí Minh

[email protected],

Tóm t t. th nh thành công quy trình phân tích các thành ph n arsenic c m m b

pháp HG-AAS ng arsenic t ng (tAs) c phân tích sau khi phá m u b

t k t h p trong bình Teflon nhi 450 o As (V) v As (III) b ng h n h p

ch t kh KI/acid ascorbic. V i arsenic (iAs), m c th y phân b ng dung d ch HCl trong 14 gi ,

ti p t c chuy n As (V) v As (III) r i ph n ng v i hydrazine 1,5%. Dùng CHCl3 chi t và chi t l i trong

HNO3. ng arsenic h (oAs) c tính b ng hi u s ng tAs và iAs. c

kho ng n tuy n tính 2 - g/L và ng chu n y = 0,0128x + 0, ,9996

trong kho ng n 2 - g/L.

tAs và iAs 05 mg/L i v i tAs, hi

arsenic arsenic

r < 10% và RSDR iAs,

83,6 110%; RSDr < 11%, RSDR < 14%.

t oAs.

T khóa. ng arsenic t ng arsenic c m m, HG-AAS, chi t.

VALIDATION OF AN ANALYTICAL METHOD FOR THE DETERMINATION OF

INORGANIC AND ORGANIC ARSENIC IN FISH SAUCE BY HYDRIDE

GENERATION ATOMIC ABSORPTION SPECTROSCOPY

Abstract. The validation of an analytical method was carried out for the determination of arsenic

components in fish sauce by HG-AAS. The total arsenic content (tAs) was analyzed after digesting the

sample by dry and wet combined digestion method in a Teflon flask at 450 °C and then reducing As (V) to

As (III) with a mixture of reducing agents KI/ascorbic acid. For inorganic arsenic content (iAs), the sample

was hydrolyzed with HCl solution for 14 hours, converted As (V) to As (III), then reacted with hydrazine

1.5%. Extracted in CHCl3 and re-extracted in HNO3. The organic arsenic content (oAs) was calculated by

the difference tAs and iAs. Determined the linear concentration range 2 -

was y = 0.0128x + 0.0007 with R² = 0.9996 at the concentration range 2 -

and inorganic arsenic contents were found and all they were 0.015 mg/L and 0.05 mg/L, respectively. For

total arsenic, the recovery efficiencies on the organic arsenic standard and inorganic arsenic standard all

ranged from 81 to 109%; repeatability RSDr< 10% and reproducability RSDR < 12%. For inorganic arsenic,

the recovery efficiency ranged from 83.6 to 110%; RSDr < 11% and RSDR < 14%. Determined As content

in representative fish sauce samples, some samples of high protein had total As content exceeding the

permitted level of the Ministry of Health, but mainly was organic As.

Keywords. total arsenic content, inorganic arsenic content, fish sauce, HG-AAS, extraction.

1

c m m là gia v c s d ng trong h u h i Vi t Nam nói riêng và các

c m m không ch giúp c mà còn là ngu n cung c p

t s lo i axit amin thi t y u hay ng ch t s ch ng l i tình tr ng thi u s t

nhi u qu c gia [1-3] c m c ch bi n b ng cách h n h p nguyên li u g m cá và mu i theo t

l nh nh trong th i gian t m lên. Tuy arsenic trong các sinh v t bi n ch y u i d ng