Chemistry Reference
In-Depth Information
Table 16.1
Some examples of the flow-based techniques and greener strategies related to replacement of toxic reagents, miniaturization of reagents and
wastes, recovery of reagents, on-line decontamination of wastes, reagent-free methodologies, among others.
Flow-based
procedure
Analyte/Sample
Sample/Reagent
consumption
Waste
generation
Sampling
frequency (h
−1
)
Precision
(
Limit of
detection
Reference
%
R.S.D.)
Multi-Syringe
FIA-UV
Nitro-substituted phenols
in mineral, tap, and sea
water
1.5 ml of sample. The use
of organic solvents is
circumvented
Not informed
135
≤
5.0
0.3-
3.2
[26]
μ
M l
−1
Closed FIA-FTIR
system
Malathion in commercial
formulations
5 ml of sample injected in
a closed manifold in which
2 ml of CHCL
3
was
recirculated
2 ml of CHCL
3
30
0.2-0.8
12
μ
g l
−1
[28]
FIA-UV
Chloride in natural
waters utilizing Hg(SCN)
2
immobilized in epoxy
resin
Sample-500
l;
Fe(III)-50 mg/determination;
Hg(II)-12 mg/det.-;
SCN-0.07 mg/det.-
μ
400
reduction of
waste
generation
%
100
2.2
1.4 × 10
−5
mol l
−1
[29]
FIA-
Chemiluminescence
Chlorpyrifos in fruits
∼
1 ml
Not informed
120
< 3.0
0.18 ng
ml
−1
[30]
FIA-UV
Carbaryl in natural
waters
1.9
g of p-aminophenol
and 5.7
μ
2.6 ml
55
0.7
1.7
μ
g l
−1
[31]
g of potassium
metaperiodate
μ
FIA-UV
Free-chlorine in waters
The consumption of
reagents was reduced
20 000 fold
Not informed
60
0.9
6.8
μ
g l
−1
[32]
Cyclic FIA-UV/Vis
Lead in gasoline using
Arsenazo (III)
20
μ
l injected volume
Recirculation
of reagents
Not informed
0.88-1.85
0.04 mg l
−1
[34]
SIA-UV
Calcium, iron and
magnesium in food
150
l of
HNO
3
, and 30 and 112
μ
l of sample, 75
μ
Not informed
7
≥
4.0
Not
informed
[47]
μ
g
of complexing reagents
SIA-Potentiometric
titration
Acidity in soft drinks
110
μ
l of sample
Not informed
45
≥
0.5
Not
informed
[48]
SIA-UV
Lactic acid in yogurt and
fermented mash samples
100
l of
reagent (Ce
4
+
) and 100
μ
l of sample, 50
μ
Not informed
22
1.5
0.16 mg l
−1
[56]
μ
l
of carrier (H
2
SO
4
)
SIA-UV
Sulfate in water and
biodiesel samples
83
μ
l of sample and 166
μ
l
Not informed
6
0.32
a
1.42 mg l
−1
[57]
of reagents
μ
SI
Ammonia, glycerol,
glucose and free iron for
monitoring of
fermentations
μ
l amounts
∼
30 ml for 40
assays
Not informed
1.5
ppm range
[70]
