微波消解-电感耦合等离子体质谱仪测定大米食品中铬、铜、砷、镉、铅、汞的含量
元素 | 线性回归方程 | 相关系数 |
52Cr | Y=9303.318*X+2078.716 | R2=1.0000 |
63Cu | Y=11499.132*X+31663.216 | R2=0.9998 |
75As | Y=862.151*X+363.243 | R2=0.9999 |
111Cd | Y=5262.585*X+973.225 | R2=0.9999 |
202Hg | Y=25034.678*X+632.509 | R2=0.9993 |
208Pb | Y=106898.428*X+22294.953 | R2=0.9999 |
表2 11次测量的荧光强度值及检出限
Table 2 The intensity of fluorescence measured by 11 measurements and the limits detection
次数 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | LOD |
52Cr | 3552.5 | 3276.5 | 3519.2 | 3456.5 | 3471.5 | 3348.5 | 3698.9 | 3542.5 | 3624.6 | 3510.5 | 3718.6 | 0.043 |
63Cu | 21753.7 | 21880.6 | 22959.3 | 21944.7 | 22142.8 | 21770.1 | 22217.9 | 21634.8 | 21883.3 | 23955.1 | 25201.5 | 0.29 |
75As | 436.7 | 457.3 | 484.0 | 415.3 | 440.0 | 419.0 | 424.0 | 460.0 | 418.0 | 552.0 | 684.2 | 0.28 |
111Cd | 508.7 | 536.7 | 532.7 | 523.3 | 556.0 | 561.0 | 508.0 | 544.0 | 522.0 | 608.0 | 552.0 | 0.016 |
202Hg | 453.3 | 386.7 | 364.0 | 364.7 | 430.0 | 301.3 | 667.4 | 469.3 | 426.0 | 392.7 | 380.0 | 0.011 |
208Pb | 100907.6 | 100134.5 | 103533.0 | 104030.1 | 102219.3 | 101330.9 | 102525.2 | 101341.3 | 104973.0 | 119234.4 | 119228.0 | 0.20 |
52Cr | 1 | 2 | 3 | 4 | 5 | 6 | 平均值 | 相对标准偏差 |
测定低限 | 0.4953 | 0.4937 | 0.4889 | 0.4952 | 0.4671 | 0.5456 | 0.4976 | 5.2% |
一合适点 | 3.7023 | 3.7233 | 3.6378 | 3.7650 | 3.6583 | 3.4807 | 3.6612 | 2.7% |
常见限量 | 1.3677 | 1.4057 | 1.3644 | 1.3972 | 1.4261 | 1.4278 | 1.3981 | 2.0% |
63Cu | 1 | 2 | 3 | 4 | 5 | 6 | 平均值 | 相对标准偏差 |
测定低限 | 3.6900 | 3.4937 | 3.7806 | 3.9360 | 3.7272 | 3.7528 | 3.7301 | 3.8% |
一合适点 | 35.3979 | 35.7446 | 35.3302 | 36.5062 | 35.0086 | 33.8673 | 35.3092 | 2.5% |
常见限量 | 4.1038 | 4.6297 | 4.4731 | 4.8764 | 4.6682 | 4.8218 | 4.5955 | 6.1% |
75As | 1 | 2 | 3 | 4 | 5 | 6 | 平均值 | 相对标准偏差 |
测定低限 | 0.2933 | 0.2996 | 0.3710 | 0.3134 | 0.3565 | 0.3393 | 0.3288 | 9.6% |
一合适点 | 3.6913 | 3.6618 | 3.5785 | 3.6760 | 3.6669 | 3.6569 | 3.6553 | 1.1% |
常见限量 | 0.8049 | 0.7462 | 0.7467 | 0.7947 | 0.7336 | 0.7704 | 0.7661 | 3.8% |
111Cd | 1 | 2 | 3 | 4 | 5 | 6 | 平均值 | 相对标准偏差 |
测定低限 | 0.0640 | 0.0643 | 0.0538 | 0.0616 | 0.0597 | 0.0692 | 0.0621 | 8.3% |
一合适点 | 3.3701 | 3.4319 | 3.3329 | 3.3962 | 3.3639 | 3.2300 | 3.3542 | 2.1% |
常见限量 | 0.2102 | 0.2065 | 0.2084 | 0.2227 | 0.2159 | 0.2164 | 0.2134 | 2.9% |
202Hg | 1 | 2 | 3 | 4 | 5 | 6 | 平均值 | 相对标准偏差 |
测定低限 | 0.0626 | 0.0604 | 0.0604 | 0.0482 | 0.0533 | 0.0466 | 0.0553 | 12.4% |
一合适点 | 0.2619 | 0.2291 | 0.2394 | 0.2286 | 0.2540 | 0.2525 | 0.2442 | 5.7% |
常见限量 | 0.2440 | 0.2586 | 0.2659 | 0.2750 | 0.2776 | 0.2698 | 0.2652 | 4.7% |
208Pb | 1 | 2 | 3 | 4 | 5 | 6 | 平均值 | 相对标准偏差 |
测定低限 | 1.2362 | 1.2323 | 1.0346 | 1.2288 | 1.2202 | 1.2592 | 1.2019 | 6.9% |
一合适点 | 5.0312 | 5.0791 | 5.1033 | 5.1280 | 5.0349 | 4.8255 | 5.0337 | 2.2% |
常见限量 | 2.1171 | 1.9534 | 2.1140 | 2.0816 | 1.9531 | 1.9647 | 2.0307 | 4.0% |
元素 | 1 | 2 | 3 | 4 | 5 | 6 | 平均值 | 相对标准偏差 |
52Cr | 1.07 | 1.09 | 1.09 | 1.06 | 1.05 | 1.08 | 1.1 | 1.6% |
63Cu | 3.39 | 3.48 | 3.55 | 3.44 | 3.45 | 3.50 | 3.5 | 1.7% |
75As | N.D. | N.D. | N.D. | N.D. | N.D. | N.D. | - | - |
111Cd | 0.0831 | 0.0836 | 0.0901 | 0.0865 | 0.0843 | 0.0871 | 0.086 | 3.1% |
202Hg | 0.00830 | 0.00775 | 0.00702 | 0.00798 | 0.00716 | 0.00699 | 0.0075 | 7.4% |
208Pb | 0.0319 | 0.0320 | 0.0296 | 0.0282 | 0.0362 | 0.0373 | 0.033 | 10.9% |
元素 | 本底值(mg/kg) | 加标量(mg/kg) | 回收率(%) | 平均回收率(%) | RSD(%) |
52Cr | 1.07 | 0.50 | 94.7 | 95.1 | 0.39 |
1.0 | 95.4 | ||||
1.5 | 95.2 | ||||
63Cu | 3.47 | 2.0 | 105.8 | 97.3 | 7.7 |
4.0 | 94.4 | ||||
6.0 | 91.7 | ||||
75As | N.D. | 0.030 | 91.5 | 99.5 | 8.0 |
0.060 | 99.7 | ||||
0.090 | 107.4 | ||||
114Cd | 0.086 | 0.050 | 107.2 | 101.9 | 5.9 |
0.10 | 103.1 | ||||
0.15 | 95.3 | ||||
202Hg | 0.0075 | 0.0030 | 87.8 | 95.2 | 7.0 |
0.020 | 97.1 | ||||
0.030 | 100.8 | ||||
208Pb | 0.033 | 0.020 | 92.6 | 101.1 | 9.7 |
0.040 | 112.0 | ||||
0.060 | 98.9 |
表6 有证标准物质测定值与标准值比较(n=3)
Table 6 Results for the determination of elements in the certificate(n=3)
标准物质 | 元素 | 标准值mg/kg | 实测值mg/kg | 平均值mg/kg | 相对标准偏差RSD/% |
辽宁大米GBW10043 | Cr | 0.14±0.05 | 0.105 | 0.11 | 2.6 |
0.108 | |||||
0.103 | |||||
Cu | 1.7±0.1 | 1.76 | 1.8 | 1.8 | |
1.82 | |||||
1.78 | |||||
As | 0.114±0.018 | 0.0962 | 0.10 | 7.9 | |
0.0959 | |||||
0.110 | |||||
Cd | 0.012±0.003 | 0.0134 | 0.014 | 6.5 | |
0.0146 | |||||
0.0129 | |||||
Hg | 0.0048±0.0008 | 0.00502 | 0.0049 | 3.1 | |
0.00499 | |||||
0.00474 | |||||
Pb | 0.075±0.025 | 0.0778 | 0.080 | 2.5 | |
0.0816 | |||||
0.0809 | |||||
蒜粉GBW10022 | Cr | 0.30±0.07 | 0.265 | 0.26 | 1.3 |
0.263 | |||||
0.259 | |||||
Cu | 4.6±0.4 | 4.87 | 4.8 | 1.3 | |
4.88 | |||||
4.77 | |||||
As | 0.31±0.04 | 0.342 | 0.33 | 4.9 | |
0.330 | |||||
0.310 | |||||
Cd | 0.062±0.003 | 0.0623 | 0.061 | 2.5 | |
0.0595 | |||||
0.0600 | |||||
Hg | 0.0040±0.0015 | 0.00292 | 0.0028 | 4.0 | |
0.00285 | |||||
0.00270 | |||||
Pb | 0.72±0.09 | 0.695 | 0.68 | 1.8 | |
0.683 | |||||
0.671 |